BE Services split (#964)

BE Services split:
* Unrelated logic moved from ClusterService to proper services
* KafkaCluster existence check moved to controllers level
* useless interfaces removed

kafka-ui-api/src/main/java/com/provectus/kafka/ui/controller/AbstractController.java

@@ -0,0 +1,22 @@
+package com.provectus.kafka.ui.controller;
+
+import com.provectus.kafka.ui.exception.ClusterNotFoundException;
+import com.provectus.kafka.ui.model.KafkaCluster;
+import com.provectus.kafka.ui.service.ClustersStorage;
+import org.springframework.beans.factory.annotation.Autowired;
+
+public abstract class AbstractController {
+
+  private ClustersStorage clustersStorage;
+
+  protected KafkaCluster getCluster(String name) {
+    return clustersStorage.getClusterByName(name)
+        .orElseThrow(() -> new ClusterNotFoundException(
+            String.format("Cluster with name '%s' not found", name)));
+  }
+
+  @Autowired
+  public void setClustersStorage(ClustersStorage clustersStorage) {
+    this.clustersStorage = clustersStorage;
+  }
+}

kafka-ui-api/src/main/java/com/provectus/kafka/ui/controller/BrokersController.java

@@ -7,7 +7,7 @@ import com.provectus.kafka.ui.model.BrokerDTO;
 import com.provectus.kafka.ui.model.BrokerLogdirUpdateDTO;
 import com.provectus.kafka.ui.model.BrokerMetricsDTO;
 import com.provectus.kafka.ui.model.BrokersLogdirsDTO;
-import com.provectus.kafka.ui.service.ClusterService;
+import com.provectus.kafka.ui.service.BrokerService;
 import java.util.List;
 import lombok.RequiredArgsConstructor;
 import lombok.extern.log4j.Log4j2;
@@ -20,13 +20,13 @@ import reactor.core.publisher.Mono;
 @RestController
 @RequiredArgsConstructor
 @Log4j2
-public class BrokersController implements BrokersApi {
-  private final ClusterService clusterService;
+public class BrokersController extends AbstractController implements BrokersApi {
+  private final BrokerService brokerService;
 
   @Override
   public Mono<ResponseEntity<BrokerMetricsDTO>> getBrokersMetrics(String clusterName, Integer id,
                                                                ServerWebExchange exchange) {
-    return clusterService.getBrokerMetrics(clusterName, id)
+    return brokerService.getBrokerMetrics(getCluster(clusterName), id)
         .map(ResponseEntity::ok)
         .onErrorReturn(ResponseEntity.notFound().build());
   }
@@ -34,7 +34,7 @@ public class BrokersController implements BrokersApi {
   @Override
   public Mono<ResponseEntity<Flux<BrokerDTO>>> getBrokers(String clusterName,
                                                        ServerWebExchange exchange) {
-    return Mono.just(ResponseEntity.ok(clusterService.getBrokers(clusterName)));
+    return Mono.just(ResponseEntity.ok(brokerService.getBrokers(getCluster(clusterName))));
   }
 
   @Override
@@ -42,13 +42,15 @@ public class BrokersController implements BrokersApi {
                                                                          List<Integer> brokers,
                                                                          ServerWebExchange exchange
   ) {
-    return Mono.just(ResponseEntity.ok(clusterService.getAllBrokersLogdirs(clusterName, brokers)));
+    return Mono.just(ResponseEntity.ok(
+        brokerService.getAllBrokersLogdirs(getCluster(clusterName), brokers)));
   }
 
   @Override
   public Mono<ResponseEntity<Flux<BrokerConfigDTO>>> getBrokerConfig(String clusterName, Integer id,
                                                                   ServerWebExchange exchange) {
-    return Mono.just(ResponseEntity.ok(clusterService.getBrokerConfig(clusterName, id)));
+    return Mono.just(ResponseEntity.ok(
+        brokerService.getBrokerConfig(getCluster(clusterName), id)));
   }
 
   @Override
@@ -56,7 +58,7 @@ public class BrokersController implements BrokersApi {
       String clusterName, Integer id, Mono<BrokerLogdirUpdateDTO> brokerLogdir,
       ServerWebExchange exchange) {
     return brokerLogdir
-        .flatMap(bld -> clusterService.updateBrokerLogDir(clusterName, id, bld))
+        .flatMap(bld -> brokerService.updateBrokerLogDir(getCluster(clusterName), id, bld))
         .map(ResponseEntity::ok);
   }
 
@@ -67,8 +69,8 @@ public class BrokersController implements BrokersApi {
                                                              Mono<BrokerConfigItemDTO> brokerConfig,
                                                              ServerWebExchange exchange) {
     return brokerConfig
-        .flatMap(bci -> clusterService.updateBrokerConfigByName(
-            clusterName, id, name, bci.getValue()))
+        .flatMap(bci -> brokerService.updateBrokerConfigByName(
+            getCluster(clusterName), id, name, bci.getValue()))
         .map(ResponseEntity::ok);
   }
 }

kafka-ui-api/src/main/java/com/provectus/kafka/ui/controller/ConsumerGroupsController.java

@@ -3,14 +3,12 @@ package com.provectus.kafka.ui.controller;
 import static java.util.stream.Collectors.toMap;
 
 import com.provectus.kafka.ui.api.ConsumerGroupsApi;
-import com.provectus.kafka.ui.exception.ClusterNotFoundException;
 import com.provectus.kafka.ui.exception.ValidationException;
 import com.provectus.kafka.ui.model.ConsumerGroupDTO;
 import com.provectus.kafka.ui.model.ConsumerGroupDetailsDTO;
 import com.provectus.kafka.ui.model.ConsumerGroupOffsetsResetDTO;
 import com.provectus.kafka.ui.model.PartitionOffsetDTO;
-import com.provectus.kafka.ui.service.ClusterService;
-import com.provectus.kafka.ui.service.ClustersStorage;
+import com.provectus.kafka.ui.service.ConsumerGroupService;
 import com.provectus.kafka.ui.service.OffsetsResetService;
 import java.util.Map;
 import java.util.Optional;
@@ -26,22 +24,22 @@ import reactor.core.publisher.Mono;
 @RestController
 @RequiredArgsConstructor
 @Log4j2
-public class ConsumerGroupsController implements ConsumerGroupsApi {
-  private final ClusterService clusterService;
+public class ConsumerGroupsController extends AbstractController implements ConsumerGroupsApi {
+
+  private final ConsumerGroupService consumerGroupService;
   private final OffsetsResetService offsetsResetService;
-  private final ClustersStorage clustersStorage;
 
   @Override
   public Mono<ResponseEntity<Void>> deleteConsumerGroup(String clusterName, String id,
                                                         ServerWebExchange exchange) {
-    return clusterService.deleteConsumerGroupById(clusterName, id)
+    return consumerGroupService.deleteConsumerGroupById(getCluster(clusterName), id)
         .map(ResponseEntity::ok);
   }
 
   @Override
   public Mono<ResponseEntity<ConsumerGroupDetailsDTO>> getConsumerGroup(
       String clusterName, String consumerGroupId, ServerWebExchange exchange) {
-    return clusterService.getConsumerGroupDetail(clusterName, consumerGroupId)
+    return consumerGroupService.getConsumerGroupDetail(getCluster(clusterName), consumerGroupId)
         .map(ResponseEntity::ok);
   }
 
@@ -49,7 +47,7 @@ public class ConsumerGroupsController implements ConsumerGroupsApi {
   @Override
   public Mono<ResponseEntity<Flux<ConsumerGroupDTO>>> getConsumerGroups(String clusterName,
                                                                      ServerWebExchange exchange) {
-    return clusterService.getConsumerGroups(clusterName)
+    return consumerGroupService.getConsumerGroups(getCluster(clusterName))
         .map(Flux::fromIterable)
         .map(ResponseEntity::ok)
         .switchIfEmpty(Mono.just(ResponseEntity.notFound().build()));
@@ -58,7 +56,8 @@ public class ConsumerGroupsController implements ConsumerGroupsApi {
   @Override
   public Mono<ResponseEntity<Flux<ConsumerGroupDTO>>> getTopicConsumerGroups(
       String clusterName, String topicName, ServerWebExchange exchange) {
-    return clusterService.getConsumerGroups(clusterName, Optional.of(topicName))
+    return consumerGroupService.getConsumerGroups(
+        getCluster(clusterName), Optional.of(topicName))
         .map(Flux::fromIterable)
         .map(ResponseEntity::ok)
         .switchIfEmpty(Mono.just(ResponseEntity.notFound().build()));
@@ -71,9 +70,7 @@ public class ConsumerGroupsController implements ConsumerGroupsApi {
                                                                   consumerGroupOffsetsReset,
                                                               ServerWebExchange exchange) {
     return consumerGroupOffsetsReset.flatMap(reset -> {
-      var cluster =
-          clustersStorage.getClusterByName(clusterName).orElseThrow(ClusterNotFoundException::new);
-
+      var cluster = getCluster(clusterName);
       switch (reset.getResetType()) {
         case EARLIEST:
           return offsetsResetService

kafka-ui-api/src/main/java/com/provectus/kafka/ui/controller/KafkaConnectController.java

@@ -23,19 +23,19 @@ import reactor.core.publisher.Mono;
 @RestController
 @RequiredArgsConstructor
 @Log4j2
-public class KafkaConnectController implements KafkaConnectApi {
+public class KafkaConnectController extends AbstractController implements KafkaConnectApi {
   private final KafkaConnectService kafkaConnectService;
 
   @Override
   public Mono<ResponseEntity<Flux<ConnectDTO>>> getConnects(String clusterName,
                                                          ServerWebExchange exchange) {
-    return kafkaConnectService.getConnects(clusterName).map(ResponseEntity::ok);
+    return kafkaConnectService.getConnects(getCluster(clusterName)).map(ResponseEntity::ok);
   }
 
   @Override
   public Mono<ResponseEntity<Flux<String>>> getConnectors(String clusterName, String connectName,
                                                           ServerWebExchange exchange) {
-    Flux<String> connectors = kafkaConnectService.getConnectors(clusterName, connectName);
+    var connectors = kafkaConnectService.getConnectors(getCluster(clusterName), connectName);
     return Mono.just(ResponseEntity.ok(connectors));
   }
 
@@ -43,7 +43,7 @@ public class KafkaConnectController implements KafkaConnectApi {
   public Mono<ResponseEntity<ConnectorDTO>> createConnector(String clusterName, String connectName,
                                                          @Valid Mono<NewConnectorDTO> connector,
                                                          ServerWebExchange exchange) {
-    return kafkaConnectService.createConnector(clusterName, connectName, connector)
+    return kafkaConnectService.createConnector(getCluster(clusterName), connectName, connector)
         .map(ResponseEntity::ok);
   }
 
@@ -51,7 +51,7 @@ public class KafkaConnectController implements KafkaConnectApi {
   public Mono<ResponseEntity<ConnectorDTO>> getConnector(String clusterName, String connectName,
                                                       String connectorName,
                                                       ServerWebExchange exchange) {
-    return kafkaConnectService.getConnector(clusterName, connectName, connectorName)
+    return kafkaConnectService.getConnector(getCluster(clusterName), connectName, connectorName)
         .map(ResponseEntity::ok);
   }
 
@@ -59,7 +59,7 @@ public class KafkaConnectController implements KafkaConnectApi {
   public Mono<ResponseEntity<Void>> deleteConnector(String clusterName, String connectName,
                                                     String connectorName,
                                                     ServerWebExchange exchange) {
-    return kafkaConnectService.deleteConnector(clusterName, connectName, connectorName)
+    return kafkaConnectService.deleteConnector(getCluster(clusterName), connectName, connectorName)
         .map(ResponseEntity::ok);
   }
 
@@ -70,7 +70,8 @@ public class KafkaConnectController implements KafkaConnectApi {
       String search,
       ServerWebExchange exchange
   ) {
-    return Mono.just(ResponseEntity.ok(kafkaConnectService.getAllConnectors(clusterName, search)));
+    return Mono.just(ResponseEntity.ok(
+        kafkaConnectService.getAllConnectors(getCluster(clusterName), search)));
   }
 
   @Override
@@ -78,7 +79,8 @@ public class KafkaConnectController implements KafkaConnectApi {
                                                                       String connectName,
                                                                       String connectorName,
                                                                       ServerWebExchange exchange) {
-    return kafkaConnectService.getConnectorConfig(clusterName, connectName, connectorName)
+    return kafkaConnectService
+        .getConnectorConfig(getCluster(clusterName), connectName, connectorName)
         .map(ResponseEntity::ok);
   }
 
@@ -89,7 +91,7 @@ public class KafkaConnectController implements KafkaConnectApi {
                                                             @Valid Mono<Object> requestBody,
                                                             ServerWebExchange exchange) {
     return kafkaConnectService
-        .setConnectorConfig(clusterName, connectName, connectorName, requestBody)
+        .setConnectorConfig(getCluster(clusterName), connectName, connectorName, requestBody)
         .map(ResponseEntity::ok);
   }
 
@@ -98,7 +100,8 @@ public class KafkaConnectController implements KafkaConnectApi {
                                                          String connectorName,
                                                          ConnectorActionDTO action,
                                                          ServerWebExchange exchange) {
-    return kafkaConnectService.updateConnectorState(clusterName, connectName, connectorName, action)
+    return kafkaConnectService
+        .updateConnectorState(getCluster(clusterName), connectName, connectorName, action)
         .map(ResponseEntity::ok);
   }
 
@@ -108,21 +111,24 @@ public class KafkaConnectController implements KafkaConnectApi {
                                                                String connectorName,
                                                                ServerWebExchange exchange) {
     return Mono.just(ResponseEntity
-        .ok(kafkaConnectService.getConnectorTasks(clusterName, connectName, connectorName)));
+        .ok(kafkaConnectService
+            .getConnectorTasks(getCluster(clusterName), connectName, connectorName)));
   }
 
   @Override
   public Mono<ResponseEntity<Void>> restartConnectorTask(String clusterName, String connectName,
                                                          String connectorName, Integer taskId,
                                                          ServerWebExchange exchange) {
-    return kafkaConnectService.restartConnectorTask(clusterName, connectName, connectorName, taskId)
+    return kafkaConnectService
+        .restartConnectorTask(getCluster(clusterName), connectName, connectorName, taskId)
         .map(ResponseEntity::ok);
   }
 
   @Override
   public Mono<ResponseEntity<Flux<ConnectorPluginDTO>>> getConnectorPlugins(
       String clusterName, String connectName, ServerWebExchange exchange) {
-    return kafkaConnectService.getConnectorPlugins(clusterName, connectName)
+    return kafkaConnectService
+        .getConnectorPlugins(getCluster(clusterName), connectName)
         .map(ResponseEntity::ok);
   }
 
@@ -132,7 +138,8 @@ public class KafkaConnectController implements KafkaConnectApi {
         String clusterName, String connectName, String pluginName, @Valid Mono<Object> requestBody,
         ServerWebExchange exchange) {
     return kafkaConnectService
-        .validateConnectorPluginConfig(clusterName, connectName, pluginName, requestBody)
+        .validateConnectorPluginConfig(
+            getCluster(clusterName), connectName, pluginName, requestBody)
         .map(ResponseEntity::ok);
   }
 }

kafka-ui-api/src/main/java/com/provectus/kafka/ui/controller/KsqlController.java

@@ -14,7 +14,7 @@ import reactor.core.publisher.Mono;
 @RestController
 @RequiredArgsConstructor
 @Log4j2
-public class KsqlController implements KsqlApi {
+public class KsqlController extends AbstractController implements KsqlApi {
   private final KsqlService ksqlService;
 
   @Override
@@ -22,6 +22,7 @@ public class KsqlController implements KsqlApi {
                                                                       Mono<KsqlCommandDTO>
                                                                           ksqlCommand,
                                                                       ServerWebExchange exchange) {
-    return ksqlService.executeKsqlCommand(clusterName, ksqlCommand).map(ResponseEntity::ok);
+    return ksqlService.executeKsqlCommand(getCluster(clusterName), ksqlCommand)
+        .map(ResponseEntity::ok);
   }
 }

kafka-ui-api/src/main/java/com/provectus/kafka/ui/controller/MessagesController.java

@@ -7,7 +7,8 @@ import com.provectus.kafka.ui.model.SeekDirectionDTO;
 import com.provectus.kafka.ui.model.SeekTypeDTO;
 import com.provectus.kafka.ui.model.TopicMessageEventDTO;
 import com.provectus.kafka.ui.model.TopicMessageSchemaDTO;
-import com.provectus.kafka.ui.service.ClusterService;
+import com.provectus.kafka.ui.service.MessagesService;
+import com.provectus.kafka.ui.service.TopicsService;
 import java.util.Collections;
 import java.util.List;
 import java.util.Optional;
@@ -26,15 +27,16 @@ import reactor.core.publisher.Mono;
 @RestController
 @RequiredArgsConstructor
 @Log4j2
-public class MessagesController implements MessagesApi {
-  private final ClusterService clusterService;
+public class MessagesController extends AbstractController implements MessagesApi {
+  private final MessagesService messagesService;
+  private final TopicsService topicsService;
 
   @Override
   public Mono<ResponseEntity<Void>> deleteTopicMessages(
       String clusterName, String topicName, @Valid List<Integer> partitions,
       ServerWebExchange exchange) {
-    return clusterService.deleteTopicMessages(
-        clusterName,
+    return messagesService.deleteTopicMessages(
+        getCluster(clusterName),
         topicName,
         Optional.ofNullable(partitions).orElse(List.of())
     ).map(ResponseEntity::ok);
@@ -48,7 +50,8 @@ public class MessagesController implements MessagesApi {
     return parseConsumerPosition(topicName, seekType, seekTo, seekDirection)
         .map(position ->
             ResponseEntity.ok(
-                clusterService.getMessages(clusterName, topicName, position, q, limit)
+                messagesService.loadMessages(
+                    getCluster(clusterName), topicName, position, q, limit)
             )
         );
   }
@@ -56,7 +59,7 @@ public class MessagesController implements MessagesApi {
   @Override
   public Mono<ResponseEntity<TopicMessageSchemaDTO>> getTopicSchema(
       String clusterName, String topicName, ServerWebExchange exchange) {
-    return Mono.just(clusterService.getTopicSchema(clusterName, topicName))
+    return Mono.just(topicsService.getTopicSchema(getCluster(clusterName), topicName))
         .map(ResponseEntity::ok);
   }
 
@@ -65,7 +68,7 @@ public class MessagesController implements MessagesApi {
       String clusterName, String topicName, @Valid Mono<CreateTopicMessageDTO> createTopicMessage,
       ServerWebExchange exchange) {
     return createTopicMessage.flatMap(msg ->
-        clusterService.sendMessage(clusterName, topicName, msg)
+        messagesService.sendMessage(getCluster(clusterName), topicName, msg).then()
     ).map(ResponseEntity::ok);
   }
 

kafka-ui-api/src/main/java/com/provectus/kafka/ui/controller/TopicsController.java

@@ -12,7 +12,7 @@ import com.provectus.kafka.ui.model.TopicDTO;
 import com.provectus.kafka.ui.model.TopicDetailsDTO;
 import com.provectus.kafka.ui.model.TopicUpdateDTO;
 import com.provectus.kafka.ui.model.TopicsResponseDTO;
-import com.provectus.kafka.ui.service.ClusterService;
+import com.provectus.kafka.ui.service.TopicsService;
 import java.util.Optional;
 import javax.validation.Valid;
 import lombok.RequiredArgsConstructor;
@@ -27,13 +27,13 @@ import reactor.core.publisher.Mono;
 @RestController
 @RequiredArgsConstructor
 @Log4j2
-public class TopicsController implements TopicsApi {
-  private final ClusterService clusterService;
+public class TopicsController extends AbstractController implements TopicsApi {
+  private final TopicsService topicsService;
 
   @Override
   public Mono<ResponseEntity<TopicDTO>> createTopic(
       String clusterName, @Valid Mono<TopicCreationDTO> topicCreation, ServerWebExchange exchange) {
-    return clusterService.createTopic(clusterName, topicCreation)
+    return topicsService.createTopic(getCluster(clusterName), topicCreation)
         .map(s -> new ResponseEntity<>(s, HttpStatus.OK))
         .switchIfEmpty(Mono.just(ResponseEntity.notFound().build()));
   }
@@ -41,7 +41,7 @@ public class TopicsController implements TopicsApi {
   @Override
   public Mono<ResponseEntity<Void>> deleteTopic(
       String clusterName, String topicName, ServerWebExchange exchange) {
-    return clusterService.deleteTopic(clusterName, topicName).map(ResponseEntity::ok);
+    return topicsService.deleteTopic(getCluster(clusterName), topicName).map(ResponseEntity::ok);
   }
 
 
@@ -49,7 +49,7 @@ public class TopicsController implements TopicsApi {
   public Mono<ResponseEntity<Flux<TopicConfigDTO>>> getTopicConfigs(
       String clusterName, String topicName, ServerWebExchange exchange) {
     return Mono.just(
-        clusterService.getTopicConfigs(clusterName, topicName)
+        topicsService.getTopicConfigs(getCluster(clusterName), topicName)
             .map(Flux::fromIterable)
             .map(ResponseEntity::ok)
             .orElse(ResponseEntity.notFound().build())
@@ -60,7 +60,7 @@ public class TopicsController implements TopicsApi {
   public Mono<ResponseEntity<TopicDetailsDTO>> getTopicDetails(
       String clusterName, String topicName, ServerWebExchange exchange) {
     return Mono.just(
-        clusterService.getTopicDetails(clusterName, topicName)
+        topicsService.getTopicDetails(getCluster(clusterName), topicName)
             .map(ResponseEntity::ok)
             .orElse(ResponseEntity.notFound().build())
     );
@@ -73,9 +73,9 @@ public class TopicsController implements TopicsApi {
                                                         @Valid String search,
                                                         @Valid TopicColumnsToSortDTO orderBy,
                                                         ServerWebExchange exchange) {
-    return Mono.just(ResponseEntity.ok(clusterService
+    return Mono.just(ResponseEntity.ok(topicsService
         .getTopics(
-            clusterName,
+            getCluster(clusterName),
             Optional.ofNullable(page),
             Optional.ofNullable(perPage),
             Optional.ofNullable(showInternal),
@@ -88,7 +88,8 @@ public class TopicsController implements TopicsApi {
   public Mono<ResponseEntity<TopicDTO>> updateTopic(
       String clusterId, String topicName, @Valid Mono<TopicUpdateDTO> topicUpdate,
       ServerWebExchange exchange) {
-    return clusterService.updateTopic(clusterId, topicName, topicUpdate).map(ResponseEntity::ok);
+    return topicsService
+        .updateTopic(getCluster(clusterId), topicName, topicUpdate).map(ResponseEntity::ok);
   }
 
   @Override
@@ -97,7 +98,8 @@ public class TopicsController implements TopicsApi {
       Mono<PartitionsIncreaseDTO> partitionsIncrease,
       ServerWebExchange exchange) {
     return partitionsIncrease.flatMap(
-        partitions -> clusterService.increaseTopicPartitions(clusterName, topicName, partitions))
+        partitions ->
+            topicsService.increaseTopicPartitions(getCluster(clusterName), topicName, partitions))
         .map(ResponseEntity::ok);
   }
 
@@ -107,7 +109,8 @@ public class TopicsController implements TopicsApi {
       Mono<ReplicationFactorChangeDTO> replicationFactorChange,
       ServerWebExchange exchange) {
     return replicationFactorChange
-        .flatMap(rfc -> clusterService.changeReplicationFactor(clusterName, topicName, rfc))
+        .flatMap(rfc ->
+            topicsService.changeReplicationFactor(getCluster(clusterName), topicName, rfc))
         .map(ResponseEntity::ok);
   }
 }

kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/BrokerService.java

@@ -1,46 +1,171 @@
 package com.provectus.kafka.ui.service;
 
+import com.provectus.kafka.ui.exception.IllegalEntityStateException;
+import com.provectus.kafka.ui.exception.InvalidRequestApiException;
+import com.provectus.kafka.ui.exception.LogDirNotFoundApiException;
+import com.provectus.kafka.ui.exception.NotFoundException;
+import com.provectus.kafka.ui.exception.TopicOrPartitionNotFoundException;
+import com.provectus.kafka.ui.mapper.ClusterMapper;
+import com.provectus.kafka.ui.mapper.DescribeLogDirsMapper;
+import com.provectus.kafka.ui.model.BrokerConfigDTO;
 import com.provectus.kafka.ui.model.BrokerDTO;
+import com.provectus.kafka.ui.model.BrokerLogdirUpdateDTO;
+import com.provectus.kafka.ui.model.BrokerMetricsDTO;
+import com.provectus.kafka.ui.model.BrokersLogdirsDTO;
 import com.provectus.kafka.ui.model.InternalBrokerConfig;
 import com.provectus.kafka.ui.model.KafkaCluster;
+import com.provectus.kafka.ui.util.ClusterUtil;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
+import java.util.stream.Collectors;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.log4j.Log4j2;
+import org.apache.kafka.clients.admin.ConfigEntry;
 import org.apache.kafka.common.Node;
+import org.apache.kafka.common.TopicPartitionReplica;
+import org.apache.kafka.common.errors.InvalidRequestException;
+import org.apache.kafka.common.errors.LogDirNotFoundException;
+import org.apache.kafka.common.errors.TimeoutException;
+import org.apache.kafka.common.errors.UnknownTopicOrPartitionException;
+import org.apache.kafka.common.requests.DescribeLogDirsResponse;
+import org.springframework.stereotype.Service;
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
 
-public interface BrokerService {
-  /**
-   * Get brokers config as map (Config name, Config).
-   *
-   * @param cluster - cluster
-   * @param brokerId - node id
-   * @return Mono of Map(String, InternalBrokerConfig)
-   */
-  Mono<Map<String, InternalBrokerConfig>> getBrokerConfigMap(KafkaCluster cluster,
-                                                             Integer brokerId);
-
-  /**
-   * Get brokers config as Flux of InternalBrokerConfig.
-   *
-   * @param cluster - cluster
-   * @param brokerId - node id
-   * @return Flux of InternalBrokerConfig
-   */
-  Flux<InternalBrokerConfig> getBrokersConfig(KafkaCluster cluster, Integer brokerId);
-
-  /**
-   * Get active brokers in cluster.
-   *
-   * @param cluster - cluster
-   * @return Flux of Broker
-   */
-  Flux<BrokerDTO> getBrokers(KafkaCluster cluster);
-
-  /**
-   * Get cluster controller node.
-   *
-   * @param cluster - cluster
-   * @return Controller node
-   */
-  Mono<Node> getController(KafkaCluster cluster);
+@Service
+@RequiredArgsConstructor
+@Log4j2
+public class BrokerService {
+
+  private final AdminClientService adminClientService;
+  private final DescribeLogDirsMapper describeLogDirsMapper;
+  private final ClusterMapper clusterMapper;
+
+  private Mono<Map<Integer, List<ConfigEntry>>> loadBrokersConfig(
+      KafkaCluster cluster, List<Integer> brokersIds) {
+    return adminClientService.get(cluster)
+        .flatMap(ac -> ac.loadBrokersConfig(brokersIds));
+  }
+
+  private Mono<List<ConfigEntry>> loadBrokersConfig(
+      KafkaCluster cluster, Integer brokerId) {
+    return loadBrokersConfig(cluster, Collections.singletonList(brokerId))
+        .map(map -> map.values().stream()
+            .findFirst()
+            .orElseThrow(() -> new IllegalEntityStateException(
+                String.format("Config for broker %s not found", brokerId)))
+        );
+  }
+
+  public Mono<Map<String, InternalBrokerConfig>> getBrokerConfigMap(KafkaCluster cluster,
+                                                                    Integer brokerId) {
+    return loadBrokersConfig(cluster, brokerId)
+        .map(list -> list.stream()
+            .collect(Collectors.toMap(
+                ConfigEntry::name,
+                ClusterUtil::mapToInternalBrokerConfig)));
+  }
+
+  private Flux<InternalBrokerConfig> getBrokersConfig(KafkaCluster cluster, Integer brokerId) {
+    if (!cluster.getBrokers().contains(brokerId)) {
+      return Flux.error(
+          new NotFoundException(String.format("Broker with id %s not found", brokerId)));
+    }
+    return loadBrokersConfig(cluster, brokerId)
+        .map(list -> list.stream()
+            .map(ClusterUtil::mapToInternalBrokerConfig)
+            .collect(Collectors.toList()))
+        .flatMapMany(Flux::fromIterable);
+  }
+
+  public Flux<BrokerDTO> getBrokers(KafkaCluster cluster) {
+    return adminClientService
+        .get(cluster)
+        .flatMap(ReactiveAdminClient::describeCluster)
+        .map(description -> description.getNodes().stream()
+            .map(node -> {
+              BrokerDTO broker = new BrokerDTO();
+              broker.setId(node.id());
+              broker.setHost(node.host());
+              return broker;
+            }).collect(Collectors.toList()))
+        .flatMapMany(Flux::fromIterable);
+  }
+
+  public Mono<Node> getController(KafkaCluster cluster) {
+    return adminClientService
+        .get(cluster)
+        .flatMap(ReactiveAdminClient::describeCluster)
+        .map(ReactiveAdminClient.ClusterDescription::getController);
+  }
+
+  public Mono<Void> updateBrokerLogDir(KafkaCluster cluster,
+                                       Integer broker,
+                                       BrokerLogdirUpdateDTO brokerLogDir) {
+    return adminClientService.get(cluster)
+        .flatMap(ac -> updateBrokerLogDir(ac, brokerLogDir, broker));
+  }
+
+  private Mono<Void> updateBrokerLogDir(ReactiveAdminClient admin,
+                                        BrokerLogdirUpdateDTO b,
+                                        Integer broker) {
+
+    Map<TopicPartitionReplica, String> req = Map.of(
+        new TopicPartitionReplica(b.getTopic(), b.getPartition(), broker),
+        b.getLogDir());
+    return  admin.alterReplicaLogDirs(req)
+        .onErrorResume(UnknownTopicOrPartitionException.class,
+            e -> Mono.error(new TopicOrPartitionNotFoundException()))
+        .onErrorResume(LogDirNotFoundException.class,
+            e -> Mono.error(new LogDirNotFoundApiException()))
+        .doOnError(log::error);
+  }
+
+  public Mono<Void> updateBrokerConfigByName(KafkaCluster cluster,
+                                             Integer broker,
+                                             String name,
+                                             String value) {
+    return adminClientService.get(cluster)
+        .flatMap(ac -> ac.updateBrokerConfigByName(broker, name, value))
+        .onErrorResume(InvalidRequestException.class,
+            e -> Mono.error(new InvalidRequestApiException(e.getMessage())))
+        .doOnError(log::error);
+  }
+
+  private Mono<Map<Integer, Map<String, DescribeLogDirsResponse.LogDirInfo>>> getClusterLogDirs(
+      KafkaCluster cluster, List<Integer> reqBrokers) {
+    return adminClientService.get(cluster)
+        .flatMap(admin -> {
+          List<Integer> brokers = new ArrayList<>(cluster.getBrokers());
+          if (reqBrokers != null && !reqBrokers.isEmpty()) {
+            brokers.retainAll(reqBrokers);
+          }
+          return admin.describeLogDirs(brokers);
+        })
+        .onErrorResume(TimeoutException.class, (TimeoutException e) -> {
+          log.error("Error during fetching log dirs", e);
+          return Mono.just(new HashMap<>());
+        });
+  }
+
+  public Flux<BrokersLogdirsDTO> getAllBrokersLogdirs(KafkaCluster cluster, List<Integer> brokers) {
+    return getClusterLogDirs(cluster, brokers)
+        .map(describeLogDirsMapper::toBrokerLogDirsList)
+        .flatMapMany(Flux::fromIterable);
+  }
+
+  public Flux<BrokerConfigDTO> getBrokerConfig(KafkaCluster cluster, Integer brokerId) {
+    return getBrokersConfig(cluster, brokerId)
+        .map(clusterMapper::toBrokerConfig);
+  }
+
+  public Mono<BrokerMetricsDTO> getBrokerMetrics(KafkaCluster cluster, Integer id) {
+    return Mono.just(cluster.getMetrics().getInternalBrokerMetrics())
+        .map(m -> m.get(id))
+        .map(clusterMapper::toBrokerMetrics);
+  }
+
 }

kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/BrokerServiceImpl.java

@@ -1,89 +0,0 @@
-package com.provectus.kafka.ui.service;
-
-import com.provectus.kafka.ui.exception.IllegalEntityStateException;
-import com.provectus.kafka.ui.exception.NotFoundException;
-import com.provectus.kafka.ui.model.BrokerDTO;
-import com.provectus.kafka.ui.model.InternalBrokerConfig;
-import com.provectus.kafka.ui.model.KafkaCluster;
-import com.provectus.kafka.ui.util.ClusterUtil;
-import java.util.Collections;
-import java.util.List;
-import java.util.Map;
-import java.util.stream.Collectors;
-import lombok.RequiredArgsConstructor;
-import lombok.extern.log4j.Log4j2;
-import org.apache.kafka.clients.admin.ConfigEntry;
-import org.apache.kafka.common.Node;
-import org.springframework.stereotype.Service;
-import reactor.core.publisher.Flux;
-import reactor.core.publisher.Mono;
-
-@Service
-@RequiredArgsConstructor
-@Log4j2
-public class BrokerServiceImpl implements BrokerService {
-
-  private final AdminClientService adminClientService;
-
-  private Mono<Map<Integer, List<ConfigEntry>>> loadBrokersConfig(
-      KafkaCluster cluster, List<Integer> brokersIds) {
-    return adminClientService.get(cluster)
-        .flatMap(ac -> ac.loadBrokersConfig(brokersIds));
-  }
-
-  private Mono<List<ConfigEntry>> loadBrokersConfig(
-      KafkaCluster cluster, Integer brokerId) {
-    return loadBrokersConfig(cluster, Collections.singletonList(brokerId))
-        .map(map -> map.values().stream()
-            .findFirst()
-            .orElseThrow(() -> new IllegalEntityStateException(
-                String.format("Config for broker %s not found", brokerId)))
-        );
-  }
-
-  @Override
-  public Mono<Map<String, InternalBrokerConfig>> getBrokerConfigMap(KafkaCluster cluster,
-                                                                    Integer brokerId) {
-    return loadBrokersConfig(cluster, brokerId)
-        .map(list -> list.stream()
-            .collect(Collectors.toMap(
-                ConfigEntry::name,
-                ClusterUtil::mapToInternalBrokerConfig)));
-  }
-
-  @Override
-  public Flux<InternalBrokerConfig> getBrokersConfig(KafkaCluster cluster, Integer brokerId) {
-    if (!cluster.getBrokers().contains(brokerId)) {
-      return Flux.error(
-          new NotFoundException(String.format("Broker with id %s not found", brokerId)));
-    }
-    return loadBrokersConfig(cluster, brokerId)
-        .map(list -> list.stream()
-            .map(ClusterUtil::mapToInternalBrokerConfig)
-            .collect(Collectors.toList()))
-        .flatMapMany(Flux::fromIterable);
-  }
-
-  @Override
-  public Flux<BrokerDTO> getBrokers(KafkaCluster cluster) {
-    return adminClientService
-        .get(cluster)
-        .flatMap(ReactiveAdminClient::describeCluster)
-        .map(description -> description.getNodes().stream()
-            .map(node -> {
-              BrokerDTO broker = new BrokerDTO();
-              broker.setId(node.id());
-              broker.setHost(node.host());
-              return broker;
-            }).collect(Collectors.toList()))
-        .flatMapMany(Flux::fromIterable);
-  }
-
-  @Override
-  public Mono<Node> getController(KafkaCluster cluster) {
-    return adminClientService
-        .get(cluster)
-        .flatMap(ReactiveAdminClient::describeCluster)
-        .map(ReactiveAdminClient.ClusterDescription::getController);
-  }
-}

kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/ClusterService.java

@@ -1,73 +1,26 @@
 package com.provectus.kafka.ui.service;
 
 import com.provectus.kafka.ui.exception.ClusterNotFoundException;
-import com.provectus.kafka.ui.exception.IllegalEntityStateException;
-import com.provectus.kafka.ui.exception.NotFoundException;
-import com.provectus.kafka.ui.exception.TopicNotFoundException;
-import com.provectus.kafka.ui.exception.ValidationException;
 import com.provectus.kafka.ui.mapper.ClusterMapper;
-import com.provectus.kafka.ui.mapper.DescribeLogDirsMapper;
-import com.provectus.kafka.ui.model.BrokerConfigDTO;
-import com.provectus.kafka.ui.model.BrokerDTO;
-import com.provectus.kafka.ui.model.BrokerLogdirUpdateDTO;
-import com.provectus.kafka.ui.model.BrokerMetricsDTO;
-import com.provectus.kafka.ui.model.BrokersLogdirsDTO;
 import com.provectus.kafka.ui.model.ClusterDTO;
 import com.provectus.kafka.ui.model.ClusterMetricsDTO;
 import com.provectus.kafka.ui.model.ClusterStatsDTO;
-import com.provectus.kafka.ui.model.ConsumerGroupDTO;
-import com.provectus.kafka.ui.model.ConsumerGroupDetailsDTO;
-import com.provectus.kafka.ui.model.ConsumerPosition;
-import com.provectus.kafka.ui.model.CreateTopicMessageDTO;
-import com.provectus.kafka.ui.model.Feature;
-import com.provectus.kafka.ui.model.InternalTopic;
 import com.provectus.kafka.ui.model.KafkaCluster;
-import com.provectus.kafka.ui.model.PartitionsIncreaseDTO;
-import com.provectus.kafka.ui.model.PartitionsIncreaseResponseDTO;
-import com.provectus.kafka.ui.model.ReplicationFactorChangeDTO;
-import com.provectus.kafka.ui.model.ReplicationFactorChangeResponseDTO;
-import com.provectus.kafka.ui.model.TopicColumnsToSortDTO;
-import com.provectus.kafka.ui.model.TopicConfigDTO;
-import com.provectus.kafka.ui.model.TopicCreationDTO;
-import com.provectus.kafka.ui.model.TopicDTO;
-import com.provectus.kafka.ui.model.TopicDetailsDTO;
-import com.provectus.kafka.ui.model.TopicMessageEventDTO;
-import com.provectus.kafka.ui.model.TopicMessageSchemaDTO;
-import com.provectus.kafka.ui.model.TopicUpdateDTO;
-import com.provectus.kafka.ui.model.TopicsResponseDTO;
-import com.provectus.kafka.ui.serde.DeserializationService;
-import com.provectus.kafka.ui.util.ClusterUtil;
-import java.util.Collections;
-import java.util.Comparator;
 import java.util.List;
-import java.util.Optional;
-import java.util.function.Predicate;
 import java.util.stream.Collectors;
 import lombok.RequiredArgsConstructor;
-import lombok.SneakyThrows;
 import lombok.extern.log4j.Log4j2;
-import org.apache.commons.lang3.StringUtils;
-import org.apache.kafka.common.errors.GroupIdNotFoundException;
-import org.apache.kafka.common.errors.GroupNotEmptyException;
-import org.jetbrains.annotations.NotNull;
 import org.springframework.stereotype.Service;
-import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
 
 @Service
 @RequiredArgsConstructor
 @Log4j2
 public class ClusterService {
-  private static final Integer DEFAULT_PAGE_SIZE = 25;
 
   private final ClustersStorage clustersStorage;
   private final ClusterMapper clusterMapper;
-  private final KafkaService kafkaService;
-  private final AdminClientService adminClientService;
-  private final BrokerService brokerService;
-  private final ConsumingService consumingService;
-  private final DeserializationService deserializationService;
-  private final DescribeLogDirsMapper describeLogDirsMapper;
+  private final MetricsService metricsService;
 
   public List<ClusterDTO> getClusters() {
     return clustersStorage.getKafkaClusters()
@@ -76,13 +29,6 @@ public class ClusterService {
         .collect(Collectors.toList());
   }
 
-  public Mono<BrokerMetricsDTO> getBrokerMetrics(String name, Integer id) {
-    return Mono.justOrEmpty(clustersStorage.getClusterByName(name)
-        .map(c -> c.getMetrics().getInternalBrokerMetrics())
-        .map(m -> m.get(id))
-        .map(clusterMapper::toBrokerMetrics));
-  }
-
   public Mono<ClusterStatsDTO> getClusterStats(String name) {
     return Mono.justOrEmpty(
         clustersStorage.getClusterByName(name)
@@ -99,293 +45,12 @@ public class ClusterService {
     );
   }
 
-
-  public TopicsResponseDTO getTopics(String name, Optional<Integer> page,
-                                  Optional<Integer> nullablePerPage,
-                                  Optional<Boolean> showInternal,
-                                  Optional<String> search,
-                                  Optional<TopicColumnsToSortDTO> sortBy) {
-    Predicate<Integer> positiveInt = i -> i > 0;
-    int perPage = nullablePerPage.filter(positiveInt).orElse(DEFAULT_PAGE_SIZE);
-    var topicsToSkip = (page.filter(positiveInt).orElse(1) - 1) * perPage;
-    var cluster = clustersStorage.getClusterByName(name)
-        .orElseThrow(ClusterNotFoundException::new);
-    List<InternalTopic> topics = cluster.getTopics().values().stream()
-        .filter(topic -> !topic.isInternal()
-            || showInternal
-            .map(i -> topic.isInternal() == i)
-            .orElse(true))
-        .filter(topic ->
-            search
-                .map(s -> StringUtils.containsIgnoreCase(topic.getName(), s))
-                .orElse(true))
-        .sorted(getComparatorForTopic(sortBy))
-        .collect(Collectors.toList());
-    var totalPages = (topics.size() / perPage)
-        + (topics.size() % perPage == 0 ? 0 : 1);
-    return new TopicsResponseDTO()
-        .pageCount(totalPages)
-        .topics(
-            topics.stream()
-                .skip(topicsToSkip)
-                .limit(perPage)
-                .map(t ->
-                    clusterMapper.toTopic(
-                        t.toBuilder().partitions(
-                          kafkaService.getTopicPartitions(cluster, t)
-                        ).build()
-                    )
-                )
-                .collect(Collectors.toList())
-        );
-  }
-
-  private Comparator<InternalTopic> getComparatorForTopic(Optional<TopicColumnsToSortDTO> sortBy) {
-    var defaultComparator = Comparator.comparing(InternalTopic::getName);
-    if (sortBy.isEmpty()) {
-      return defaultComparator;
-    }
-    switch (sortBy.get()) {
-      case TOTAL_PARTITIONS:
-        return Comparator.comparing(InternalTopic::getPartitionCount);
-      case OUT_OF_SYNC_REPLICAS:
-        return Comparator.comparing(t -> t.getReplicas() - t.getInSyncReplicas());
-      case REPLICATION_FACTOR:
-        return Comparator.comparing(InternalTopic::getReplicationFactor);
-      case NAME:
-      default:
-        return defaultComparator;
-    }
-  }
-
-  public Optional<TopicDetailsDTO> getTopicDetails(String name, String topicName) {
-    return clustersStorage.getClusterByName(name)
-        .flatMap(c ->
-            Optional.ofNullable(c.getTopics()).map(l -> l.get(topicName)).map(
-                t -> t.toBuilder().partitions(
-                    kafkaService.getTopicPartitions(c, t)
-                ).build()
-            ).map(t -> clusterMapper.toTopicDetails(t, c.getMetrics()))
-        );
-  }
-
-  public Optional<List<TopicConfigDTO>> getTopicConfigs(String name, String topicName) {
-    return clustersStorage.getClusterByName(name)
-        .map(KafkaCluster::getTopics)
-        .map(t -> t.get(topicName))
-        .map(t -> t.getTopicConfigs().stream().map(clusterMapper::toTopicConfig)
-            .collect(Collectors.toList()));
-  }
-
-  public Mono<TopicDTO> createTopic(String clusterName, Mono<TopicCreationDTO> topicCreation) {
-    return clustersStorage.getClusterByName(clusterName).map(cluster ->
-        kafkaService.createTopic(cluster, topicCreation)
-            .doOnNext(t -> updateCluster(t, clusterName, cluster))
-            .map(clusterMapper::toTopic)
-    ).orElse(Mono.empty());
-  }
-
-  @SneakyThrows
-  public Mono<ConsumerGroupDetailsDTO> getConsumerGroupDetail(String clusterName,
-                                                           String consumerGroupId) {
-    var cluster = clustersStorage.getClusterByName(clusterName).orElseThrow(Throwable::new);
-    return kafkaService.getConsumerGroups(
-        cluster,
-        Optional.empty(),
-        Collections.singletonList(consumerGroupId)
-    ).filter(groups -> !groups.isEmpty()).map(groups -> groups.get(0)).map(
-        ClusterUtil::convertToConsumerGroupDetails
-    );
-  }
-
-  public Mono<List<ConsumerGroupDTO>> getConsumerGroups(String clusterName) {
-    return getConsumerGroups(clusterName, Optional.empty());
-  }
-
-  public Mono<List<ConsumerGroupDTO>> getConsumerGroups(String clusterName,
-                                                        Optional<String> topic) {
-    return Mono.justOrEmpty(clustersStorage.getClusterByName(clusterName))
-        .switchIfEmpty(Mono.error(ClusterNotFoundException::new))
-        .flatMap(c -> kafkaService.getConsumerGroups(c, topic, Collections.emptyList()))
-        .map(c ->
-            c.stream().map(ClusterUtil::convertToConsumerGroup).collect(Collectors.toList())
-        );
-  }
-
-  public Flux<BrokerDTO> getBrokers(String clusterName) {
-    return Mono.justOrEmpty(clustersStorage.getClusterByName(clusterName))
-        .switchIfEmpty(Mono.error(ClusterNotFoundException::new))
-        .flatMapMany(brokerService::getBrokers);
-  }
-
-  public Flux<BrokerConfigDTO> getBrokerConfig(String clusterName, Integer brokerId) {
-    return Mono.justOrEmpty(clustersStorage.getClusterByName(clusterName))
-        .switchIfEmpty(Mono.error(ClusterNotFoundException::new))
-        .flatMapMany(c -> brokerService.getBrokersConfig(c, brokerId))
-        .map(clusterMapper::toBrokerConfig);
-  }
-
-  @SneakyThrows
-  public Mono<TopicDTO> updateTopic(String clusterName, String topicName,
-                                 Mono<TopicUpdateDTO> topicUpdate) {
-    return clustersStorage.getClusterByName(clusterName).map(cl ->
-        topicUpdate
-            .flatMap(t -> kafkaService.updateTopic(cl, topicName, t))
-            .doOnNext(t -> updateCluster(t, clusterName, cl))
-            .map(clusterMapper::toTopic)
-    ).orElse(Mono.empty());
-  }
-
-  public Mono<Void> deleteTopic(String clusterName, String topicName) {
-    var cluster = clustersStorage.getClusterByName(clusterName)
-        .orElseThrow(ClusterNotFoundException::new);
-    var topic = getTopicDetails(clusterName, topicName)
-        .orElseThrow(TopicNotFoundException::new);
-    if (cluster.getFeatures().contains(Feature.TOPIC_DELETION)) {
-      return kafkaService.deleteTopic(cluster, topic.getName())
-          .doOnSuccess(t -> updateCluster(topicName, clusterName, cluster));
-    } else {
-      return Mono.error(new ValidationException("Topic deletion restricted"));
-    }
-  }
-
-  private KafkaCluster updateCluster(InternalTopic topic, String clusterName,
-                                     KafkaCluster cluster) {
-    final KafkaCluster updatedCluster = kafkaService.getUpdatedCluster(cluster, topic);
-    clustersStorage.setKafkaCluster(clusterName, updatedCluster);
-    return updatedCluster;
-  }
-
-  private KafkaCluster updateCluster(String topicToDelete, String clusterName,
-                                     KafkaCluster cluster) {
-    final KafkaCluster updatedCluster = kafkaService.getUpdatedCluster(cluster, topicToDelete);
-    clustersStorage.setKafkaCluster(clusterName, updatedCluster);
-    return updatedCluster;
-  }
-
   public Mono<ClusterDTO> updateCluster(String clusterName) {
     return clustersStorage.getClusterByName(clusterName)
-        .map(cluster -> kafkaService.getUpdatedCluster(cluster)
+        .map(cluster -> metricsService.updateClusterMetrics(cluster)
             .doOnNext(updatedCluster -> clustersStorage
                 .setKafkaCluster(updatedCluster.getName(), updatedCluster))
             .map(clusterMapper::toCluster))
         .orElse(Mono.error(new ClusterNotFoundException()));
   }
-
-  public Flux<TopicMessageEventDTO> getMessages(String clusterName, String topicName,
-                                        ConsumerPosition consumerPosition, String query,
-                                        Integer limit) {
-    return clustersStorage.getClusterByName(clusterName)
-        .map(c -> consumingService.loadMessages(c, topicName, consumerPosition, query, limit))
-        .orElse(Flux.empty());
-  }
-
-  public Mono<Void> deleteTopicMessages(String clusterName, String topicName,
-                                        List<Integer> partitions) {
-    var cluster = clustersStorage.getClusterByName(clusterName)
-        .orElseThrow(ClusterNotFoundException::new);
-    if (!cluster.getTopics().containsKey(topicName)) {
-      throw new TopicNotFoundException();
-    }
-    return consumingService.offsetsForDeletion(cluster, topicName, partitions)
-        .flatMap(offsets -> kafkaService.deleteTopicMessages(cluster, offsets));
-  }
-
-  public Mono<PartitionsIncreaseResponseDTO> increaseTopicPartitions(
-      String clusterName,
-      String topicName,
-      PartitionsIncreaseDTO partitionsIncrease) {
-    return clustersStorage.getClusterByName(clusterName).map(cluster ->
-        kafkaService.increaseTopicPartitions(cluster, topicName, partitionsIncrease)
-            .doOnNext(t -> updateCluster(t, cluster.getName(), cluster))
-            .map(t -> new PartitionsIncreaseResponseDTO()
-                .topicName(t.getName())
-                .totalPartitionsCount(t.getPartitionCount())))
-        .orElse(Mono.error(new ClusterNotFoundException(
-            String.format("No cluster for name '%s'", clusterName)
-        )));
-  }
-
-  public Mono<Void> deleteConsumerGroupById(String clusterName,
-                                            String groupId) {
-    return clustersStorage.getClusterByName(clusterName)
-        .map(cluster -> adminClientService.get(cluster)
-            .flatMap(adminClient -> adminClient.deleteConsumerGroups(List.of(groupId)))
-            .onErrorResume(this::reThrowCustomException)
-        )
-        .orElse(Mono.empty());
-  }
-
-  public TopicMessageSchemaDTO getTopicSchema(String clusterName, String topicName) {
-    var cluster = clustersStorage.getClusterByName(clusterName)
-        .orElseThrow(ClusterNotFoundException::new);
-    if (!cluster.getTopics().containsKey(topicName)) {
-      throw new TopicNotFoundException();
-    }
-    return deserializationService
-        .getRecordDeserializerForCluster(cluster)
-        .getTopicSchema(topicName);
-  }
-
-  public Mono<Void> sendMessage(String clusterName, String topicName, CreateTopicMessageDTO msg) {
-    var cluster = clustersStorage.getClusterByName(clusterName)
-        .orElseThrow(ClusterNotFoundException::new);
-    if (!cluster.getTopics().containsKey(topicName)) {
-      throw new TopicNotFoundException();
-    }
-    if (msg.getKey() == null && msg.getContent() == null) {
-      throw new ValidationException("Invalid message: both key and value can't be null");
-    }
-    if (msg.getPartition() != null
-        && msg.getPartition() > cluster.getTopics().get(topicName).getPartitionCount() - 1) {
-      throw new ValidationException("Invalid partition");
-    }
-    return kafkaService.sendMessage(cluster, topicName, msg).then();
-  }
-
-  @NotNull
-  private Mono<Void> reThrowCustomException(Throwable e) {
-    if (e instanceof GroupIdNotFoundException) {
-      return Mono.error(new NotFoundException("The group id does not exist"));
-    } else if (e instanceof GroupNotEmptyException) {
-      return Mono.error(new IllegalEntityStateException("The group is not empty"));
-    } else {
-      return Mono.error(e);
-    }
-  }
-
-  public Mono<ReplicationFactorChangeResponseDTO> changeReplicationFactor(
-      String clusterName,
-      String topicName,
-      ReplicationFactorChangeDTO replicationFactorChange) {
-    return clustersStorage.getClusterByName(clusterName).map(cluster ->
-        kafkaService.changeReplicationFactor(cluster, topicName, replicationFactorChange)
-            .doOnNext(topic -> updateCluster(topic, cluster.getName(), cluster))
-            .map(t -> new ReplicationFactorChangeResponseDTO()
-                .topicName(t.getName())
-                .totalReplicationFactor(t.getReplicationFactor())))
-        .orElse(Mono.error(new ClusterNotFoundException(
-            String.format("No cluster for name '%s'", clusterName))));
-  }
-
-  public Flux<BrokersLogdirsDTO> getAllBrokersLogdirs(String clusterName, List<Integer> brokers) {
-    return Mono.justOrEmpty(clustersStorage.getClusterByName(clusterName))
-        .flatMap(c -> kafkaService.getClusterLogDirs(c, brokers))
-        .map(describeLogDirsMapper::toBrokerLogDirsList)
-        .flatMapMany(Flux::fromIterable);
-  }
-
-  public Mono<Void> updateBrokerLogDir(
-      String clusterName, Integer id, BrokerLogdirUpdateDTO brokerLogDir) {
-    return Mono.justOrEmpty(clustersStorage.getClusterByName(clusterName))
-        .flatMap(c -> kafkaService.updateBrokerLogDir(c, id, brokerLogDir));
-  }
-
-  public Mono<Void> updateBrokerConfigByName(String clusterName,
-                                             Integer id,
-                                             String name,
-                                             String value) {
-    return Mono.justOrEmpty(clustersStorage.getClusterByName(clusterName))
-        .flatMap(c -> kafkaService.updateBrokerConfigByName(c, id, name, value));
-  }
 }

kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/ClustersMetricsScheduler.java

@@ -15,7 +15,7 @@ public class ClustersMetricsScheduler {
 
   private final ClustersStorage clustersStorage;
 
-  private final MetricsUpdateService metricsUpdateService;
+  private final MetricsService metricsService;
 
   @Scheduled(fixedRateString = "${kafka.update-metrics-rate-millis:30000}")
   public void updateMetrics() {
@@ -23,7 +23,10 @@ public class ClustersMetricsScheduler {
         .parallel()
         .runOn(Schedulers.parallel())
         .map(Map.Entry::getValue)
-        .flatMap(metricsUpdateService::updateMetrics)
+        .flatMap(cluster -> {
+          log.debug("Start getting metrics for kafkaCluster: {}", cluster.getName());
+          return metricsService.updateClusterMetrics(cluster);
+        })
         .doOnNext(s -> clustersStorage.setKafkaCluster(s.getName(), s))
         .then()
         .block();

kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/ClustersStorage.java

@@ -2,6 +2,7 @@ package com.provectus.kafka.ui.service;
 
 import com.provectus.kafka.ui.config.ClustersProperties;
 import com.provectus.kafka.ui.mapper.ClusterMapper;
+import com.provectus.kafka.ui.model.InternalTopic;
 import com.provectus.kafka.ui.model.KafkaCluster;
 import java.util.Collection;
 import java.util.HashMap;
@@ -48,8 +49,27 @@ public class ClustersStorage {
     return Optional.ofNullable(kafkaClusters.get(clusterName));
   }
 
-  public void setKafkaCluster(String key, KafkaCluster kafkaCluster) {
+  public KafkaCluster setKafkaCluster(String key, KafkaCluster kafkaCluster) {
     this.kafkaClusters.put(key, kafkaCluster);
+    return kafkaCluster;
+  }
+
+  public void onTopicDeleted(KafkaCluster cluster, String topicToDelete) {
+    var topics = Optional.ofNullable(cluster.getTopics())
+        .map(HashMap::new)
+        .orElseGet(HashMap::new);
+    topics.remove(topicToDelete);
+    var updatedCluster = cluster.toBuilder().topics(topics).build();
+    setKafkaCluster(cluster.getName(), updatedCluster);
+  }
+
+  public void onTopicUpdated(KafkaCluster cluster, InternalTopic updatedTopic) {
+    var topics = Optional.ofNullable(cluster.getTopics())
+        .map(HashMap::new)
+        .orElseGet(HashMap::new);
+    topics.put(updatedTopic.getName(), updatedTopic);
+    var updatedCluster = cluster.toBuilder().topics(topics).build();
+    setKafkaCluster(cluster.getName(), updatedCluster);
   }
 
   public Map<String, KafkaCluster> getKafkaClustersMap() {

kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/ConsumerGroupService.java

@@ -0,0 +1,133 @@
+package com.provectus.kafka.ui.service;
+
+import com.provectus.kafka.ui.model.ConsumerGroupDTO;
+import com.provectus.kafka.ui.model.ConsumerGroupDetailsDTO;
+import com.provectus.kafka.ui.model.InternalConsumerGroup;
+import com.provectus.kafka.ui.model.KafkaCluster;
+import com.provectus.kafka.ui.util.ClusterUtil;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+import java.util.Properties;
+import java.util.UUID;
+import java.util.stream.Collectors;
+import lombok.RequiredArgsConstructor;
+import org.apache.kafka.clients.consumer.ConsumerConfig;
+import org.apache.kafka.clients.consumer.KafkaConsumer;
+import org.apache.kafka.common.TopicPartition;
+import org.apache.kafka.common.serialization.BytesDeserializer;
+import org.apache.kafka.common.utils.Bytes;
+import org.springframework.stereotype.Service;
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
+
+
+@Service
+@RequiredArgsConstructor
+public class ConsumerGroupService {
+
+  private final AdminClientService adminClientService;
+
+  private Mono<List<InternalConsumerGroup>> getConsumerGroupsInternal(KafkaCluster cluster) {
+    return adminClientService.get(cluster).flatMap(ac ->
+        ac.listConsumerGroups()
+            .flatMap(groupIds -> getConsumerGroupsInternal(cluster, groupIds)));
+  }
+
+  private Mono<List<InternalConsumerGroup>> getConsumerGroupsInternal(KafkaCluster cluster,
+                                                                     List<String> groupIds) {
+    return adminClientService.get(cluster).flatMap(ac ->
+        ac.describeConsumerGroups(groupIds)
+            .map(Map::values)
+            .flatMap(descriptions ->
+                Flux.fromIterable(descriptions)
+                    .parallel()
+                    .flatMap(d ->
+                        ac.listConsumerGroupOffsets(d.groupId())
+                            .map(offsets -> ClusterUtil.convertToInternalConsumerGroup(d, offsets))
+                    )
+                    .sequential()
+                    .collectList()));
+  }
+
+  public Mono<List<InternalConsumerGroup>> getConsumerGroups(
+      KafkaCluster cluster, Optional<String> topic, List<String> groupIds) {
+    final Mono<List<InternalConsumerGroup>> consumerGroups;
+
+    if (groupIds.isEmpty()) {
+      consumerGroups = getConsumerGroupsInternal(cluster);
+    } else {
+      consumerGroups = getConsumerGroupsInternal(cluster, groupIds);
+    }
+
+    return consumerGroups.map(c ->
+        c.stream()
+            .map(d -> ClusterUtil.filterConsumerGroupTopic(d, topic))
+            .filter(Optional::isPresent)
+            .map(Optional::get)
+            .map(g ->
+                g.toBuilder().endOffsets(
+                    topicPartitionsEndOffsets(cluster, g.getOffsets().keySet())
+                ).build()
+            )
+            .collect(Collectors.toList())
+    );
+  }
+
+  public Mono<List<ConsumerGroupDTO>> getConsumerGroups(KafkaCluster cluster) {
+    return getConsumerGroups(cluster, Optional.empty());
+  }
+
+  public Mono<List<ConsumerGroupDTO>> getConsumerGroups(KafkaCluster cluster,
+                                                        Optional<String> topic) {
+    return getConsumerGroups(cluster, topic, Collections.emptyList())
+        .map(c ->
+            c.stream().map(ClusterUtil::convertToConsumerGroup).collect(Collectors.toList())
+        );
+  }
+
+  private Map<TopicPartition, Long> topicPartitionsEndOffsets(
+      KafkaCluster cluster, Collection<TopicPartition> topicPartitions) {
+    try (KafkaConsumer<Bytes, Bytes> consumer = createConsumer(cluster)) {
+      return consumer.endOffsets(topicPartitions);
+    }
+  }
+
+  public Mono<ConsumerGroupDetailsDTO> getConsumerGroupDetail(KafkaCluster cluster,
+                                                              String consumerGroupId) {
+    return getConsumerGroups(
+        cluster,
+        Optional.empty(),
+        Collections.singletonList(consumerGroupId)
+    ).filter(groups -> !groups.isEmpty()).map(groups -> groups.get(0)).map(
+        ClusterUtil::convertToConsumerGroupDetails
+    );
+  }
+
+  public Mono<Void> deleteConsumerGroupById(KafkaCluster cluster,
+                                            String groupId) {
+    return adminClientService.get(cluster)
+        .flatMap(adminClient -> adminClient.deleteConsumerGroups(List.of(groupId)));
+  }
+
+  public KafkaConsumer<Bytes, Bytes> createConsumer(KafkaCluster cluster) {
+    return createConsumer(cluster, Map.of());
+  }
+
+  public KafkaConsumer<Bytes, Bytes> createConsumer(KafkaCluster cluster,
+                                                    Map<String, Object> properties) {
+    Properties props = new Properties();
+    props.putAll(cluster.getProperties());
+    props.put(ConsumerConfig.CLIENT_ID_CONFIG, "kafka-ui-" + UUID.randomUUID());
+    props.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, cluster.getBootstrapServers());
+    props.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, BytesDeserializer.class);
+    props.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, BytesDeserializer.class);
+    props.put(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG, "earliest");
+    props.putAll(properties);
+
+    return new KafkaConsumer<>(props);
+  }
+
+}

kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/ConsumingService.java

@@ -1,119 +0,0 @@
-package com.provectus.kafka.ui.service;
-
-import com.fasterxml.jackson.databind.ObjectMapper;
-import com.provectus.kafka.ui.emitter.BackwardRecordEmitter;
-import com.provectus.kafka.ui.emitter.ForwardRecordEmitter;
-import com.provectus.kafka.ui.model.ConsumerPosition;
-import com.provectus.kafka.ui.model.KafkaCluster;
-import com.provectus.kafka.ui.model.SeekDirectionDTO;
-import com.provectus.kafka.ui.model.TopicMessageDTO;
-import com.provectus.kafka.ui.model.TopicMessageEventDTO;
-import com.provectus.kafka.ui.serde.DeserializationService;
-import com.provectus.kafka.ui.serde.RecordSerDe;
-import com.provectus.kafka.ui.util.FilterTopicMessageEvents;
-import com.provectus.kafka.ui.util.OffsetsSeekBackward;
-import com.provectus.kafka.ui.util.OffsetsSeekForward;
-import java.util.Collection;
-import java.util.List;
-import java.util.Map;
-import java.util.Optional;
-import java.util.stream.Collectors;
-import lombok.RequiredArgsConstructor;
-import lombok.extern.log4j.Log4j2;
-import org.apache.kafka.clients.consumer.Consumer;
-import org.apache.kafka.clients.consumer.KafkaConsumer;
-import org.apache.kafka.common.TopicPartition;
-import org.apache.kafka.common.utils.Bytes;
-import org.springframework.stereotype.Service;
-import org.springframework.util.StringUtils;
-import reactor.core.publisher.Flux;
-import reactor.core.publisher.FluxSink;
-import reactor.core.publisher.Mono;
-import reactor.core.scheduler.Schedulers;
-
-@Service
-@Log4j2
-@RequiredArgsConstructor
-public class ConsumingService {
-
-  private static final int MAX_RECORD_LIMIT = 100;
-  private static final int DEFAULT_RECORD_LIMIT = 20;
-
-  private final KafkaService kafkaService;
-  private final DeserializationService deserializationService;
-  private final ObjectMapper objectMapper = new ObjectMapper();
-
-  public Flux<TopicMessageEventDTO> loadMessages(KafkaCluster cluster, String topic,
-                                              ConsumerPosition consumerPosition, String query,
-                                              Integer limit) {
-    int recordsLimit = Optional.ofNullable(limit)
-        .map(s -> Math.min(s, MAX_RECORD_LIMIT))
-        .orElse(DEFAULT_RECORD_LIMIT);
-
-    java.util.function.Consumer<? super FluxSink<TopicMessageEventDTO>> emitter;
-    RecordSerDe recordDeserializer =
-        deserializationService.getRecordDeserializerForCluster(cluster);
-    if (consumerPosition.getSeekDirection().equals(SeekDirectionDTO.FORWARD)) {
-      emitter = new ForwardRecordEmitter(
-          () -> kafkaService.createConsumer(cluster),
-          new OffsetsSeekForward(topic, consumerPosition),
-          recordDeserializer
-      );
-    } else {
-      emitter = new BackwardRecordEmitter(
-          (Map<String, Object> props) -> kafkaService.createConsumer(cluster, props),
-          new OffsetsSeekBackward(topic, consumerPosition, recordsLimit),
-          recordDeserializer
-      );
-    }
-    return Flux.create(emitter)
-        .filter(m -> filterTopicMessage(m, query))
-        .takeWhile(new FilterTopicMessageEvents(recordsLimit))
-        .subscribeOn(Schedulers.elastic())
-        .share();
-  }
-
-  public Mono<Map<TopicPartition, Long>> offsetsForDeletion(KafkaCluster cluster, String topicName,
-                                                            List<Integer> partitionsToInclude) {
-    return Mono.fromSupplier(() -> {
-      try (KafkaConsumer<Bytes, Bytes> consumer = kafkaService.createConsumer(cluster)) {
-        return significantOffsets(consumer, topicName, partitionsToInclude);
-      } catch (Exception e) {
-        log.error("Error occurred while consuming records", e);
-        throw new RuntimeException(e);
-      }
-    });
-  }
-
-  /**
-   * returns end offsets for partitions where start offset != end offsets.
-   * This is useful when we need to verify that partition is not empty.
-   */
-  public static Map<TopicPartition, Long> significantOffsets(Consumer<?, ?> consumer,
-                                                              String topicName,
-                                                              Collection<Integer>
-                                                                  partitionsToInclude) {
-    var partitions = consumer.partitionsFor(topicName).stream()
-        .filter(p -> partitionsToInclude.isEmpty() || partitionsToInclude.contains(p.partition()))
-        .map(p -> new TopicPartition(topicName, p.partition()))
-        .collect(Collectors.toList());
-    var beginningOffsets = consumer.beginningOffsets(partitions);
-    var endOffsets = consumer.endOffsets(partitions);
-    return endOffsets.entrySet().stream()
-        .filter(entry -> !beginningOffsets.get(entry.getKey()).equals(entry.getValue()))
-        .collect(Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue));
-  }
-
-  private boolean filterTopicMessage(TopicMessageEventDTO message, String query) {
-    log.info("filter");
-    if (StringUtils.isEmpty(query)
-        || !message.getType().equals(TopicMessageEventDTO.TypeEnum.MESSAGE)) {
-      return true;
-    }
-
-    final TopicMessageDTO msg = message.getMessage();
-    return (!StringUtils.isEmpty(msg.getKey()) && msg.getKey().contains(query))
-        || (!StringUtils.isEmpty(msg.getContent()) && msg.getContent().contains(query));
-  }
-
-}

kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/FeatureService.java

@@ -1,15 +1,61 @@
 package com.provectus.kafka.ui.service;
 
+import static com.provectus.kafka.ui.util.Constants.DELETE_TOPIC_ENABLE;
+
 import com.provectus.kafka.ui.model.Feature;
 import com.provectus.kafka.ui.model.KafkaCluster;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Optional;
+import java.util.function.Predicate;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.log4j.Log4j2;
+import org.apache.kafka.common.Node;
+import org.springframework.stereotype.Service;
 import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
+
+@Service
+@RequiredArgsConstructor
+@Log4j2
+public class FeatureService {
+
+  private final BrokerService brokerService;
+
+  public Flux<Feature> getAvailableFeatures(KafkaCluster cluster) {
+    List<Mono<Feature>> features = new ArrayList<>();
+
+    if (Optional.ofNullable(cluster.getKafkaConnect())
+        .filter(Predicate.not(List::isEmpty))
+        .isPresent()) {
+      features.add(Mono.just(Feature.KAFKA_CONNECT));
+    }
+
+    if (cluster.getKsqldbServer() != null) {
+      features.add(Mono.just(Feature.KSQL_DB));
+    }
+
+    if (cluster.getSchemaRegistry() != null) {
+      features.add(Mono.just(Feature.SCHEMA_REGISTRY));
+    }
+
+    features.add(
+        isTopicDeletionEnabled(cluster)
+            .flatMap(r -> r ? Mono.just(Feature.TOPIC_DELETION) : Mono.empty())
+    );
+
+    return Flux.fromIterable(features).flatMap(m -> m);
+  }
 
-public interface FeatureService {
-  /**
-   * Get available features.
-   *
-   * @param cluster - cluster
-   * @return List of Feature
-   */
-  Flux<Feature> getAvailableFeatures(KafkaCluster cluster);
+  private Mono<Boolean> isTopicDeletionEnabled(KafkaCluster cluster) {
+    return brokerService.getController(cluster)
+        .map(Node::id)
+        .flatMap(broker -> brokerService.getBrokerConfigMap(cluster, broker))
+        .map(config -> {
+          if (config != null && config.get(DELETE_TOPIC_ENABLE) != null) {
+            return Boolean.parseBoolean(config.get(DELETE_TOPIC_ENABLE).getValue());
+          }
+          return false;
+        });
+  }
 }

kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/FeatureServiceImpl.java

@@ -1,62 +0,0 @@
-package com.provectus.kafka.ui.service;
-
-import static com.provectus.kafka.ui.util.Constants.DELETE_TOPIC_ENABLE;
-
-import com.provectus.kafka.ui.model.Feature;
-import com.provectus.kafka.ui.model.KafkaCluster;
-import java.util.ArrayList;
-import java.util.List;
-import java.util.Optional;
-import java.util.function.Predicate;
-import lombok.RequiredArgsConstructor;
-import lombok.extern.log4j.Log4j2;
-import org.apache.kafka.common.Node;
-import org.springframework.stereotype.Service;
-import reactor.core.publisher.Flux;
-import reactor.core.publisher.Mono;
-
-@Service
-@RequiredArgsConstructor
-@Log4j2
-public class FeatureServiceImpl implements FeatureService {
-
-  private final BrokerService brokerService;
-
-  @Override
-  public Flux<Feature> getAvailableFeatures(KafkaCluster cluster) {
-    List<Mono<Feature>> features = new ArrayList<>();
-
-    if (Optional.ofNullable(cluster.getKafkaConnect())
-        .filter(Predicate.not(List::isEmpty))
-        .isPresent()) {
-      features.add(Mono.just(Feature.KAFKA_CONNECT));
-    }
-
-    if (cluster.getKsqldbServer() != null) {
-      features.add(Mono.just(Feature.KSQL_DB));
-    }
-
-    if (cluster.getSchemaRegistry() != null) {
-      features.add(Mono.just(Feature.SCHEMA_REGISTRY));
-    }
-
-    features.add(
-        topicDeletionCheck(cluster)
-            .flatMap(r -> r ? Mono.just(Feature.TOPIC_DELETION) : Mono.empty())
-    );
-
-    return Flux.fromIterable(features).flatMap(m -> m);
-  }
-
-  private Mono<Boolean> topicDeletionCheck(KafkaCluster cluster) {
-    return brokerService.getController(cluster)
-        .map(Node::id)
-        .flatMap(broker -> brokerService.getBrokerConfigMap(cluster, broker))
-        .map(config -> {
-          if (config != null && config.get(DELETE_TOPIC_ENABLE) != null) {
-            return Boolean.parseBoolean(config.get(DELETE_TOPIC_ENABLE).getValue());
-          }
-          return false;
-        });
-  }
-}

kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/KafkaConnectService.java

@@ -21,7 +21,6 @@ import com.provectus.kafka.ui.model.KafkaConnectCluster;
 import com.provectus.kafka.ui.model.NewConnectorDTO;
 import com.provectus.kafka.ui.model.TaskDTO;
 import com.provectus.kafka.ui.model.connect.InternalConnectInfo;
-import java.util.Collection;
 import java.util.List;
 import java.util.Map;
 import java.util.function.Function;
@@ -47,25 +46,24 @@ public class KafkaConnectService {
   private final KafkaConnectMapper kafkaConnectMapper;
   private final ObjectMapper objectMapper;
 
-  public Mono<Flux<ConnectDTO>> getConnects(String clusterName) {
+  public Mono<Flux<ConnectDTO>> getConnects(KafkaCluster cluster) {
     return Mono.just(
-        Flux.fromIterable(clustersStorage.getClusterByName(clusterName)
-            .map(KafkaCluster::getKafkaConnect).stream()
-            .flatMap(Collection::stream)
-            .map(clusterMapper::toKafkaConnect)
-            .collect(Collectors.toList())
+        Flux.fromIterable(
+            cluster.getKafkaConnect().stream()
+                .map(clusterMapper::toKafkaConnect)
+                .collect(Collectors.toList())
         )
     );
   }
 
-  public Flux<FullConnectorInfoDTO> getAllConnectors(final String clusterName,
+  public Flux<FullConnectorInfoDTO> getAllConnectors(final KafkaCluster cluster,
                                                      final String search) {
-    return getConnects(clusterName)
+    return getConnects(cluster)
         .flatMapMany(Function.identity())
-        .flatMap(connect -> getConnectorNames(clusterName, connect))
-        .flatMap(pair -> getConnector(clusterName, pair.getT1(), pair.getT2()))
+        .flatMap(connect -> getConnectorNames(cluster, connect))
+        .flatMap(pair -> getConnector(cluster, pair.getT1(), pair.getT2()))
         .flatMap(connector ->
-            getConnectorConfig(clusterName, connector.getConnect(), connector.getName())
+            getConnectorConfig(cluster, connector.getConnect(), connector.getName())
                 .map(config -> InternalConnectInfo.builder()
                     .connector(connector)
                     .config(config)
@@ -74,7 +72,7 @@ public class KafkaConnectService {
         )
         .flatMap(connectInfo -> {
           ConnectorDTO connector = connectInfo.getConnector();
-          return getConnectorTasks(clusterName, connector.getConnect(), connector.getName())
+          return getConnectorTasks(cluster, connector.getConnect(), connector.getName())
               .collectList()
               .map(tasks -> InternalConnectInfo.builder()
                   .connector(connector)
@@ -85,7 +83,7 @@ public class KafkaConnectService {
         })
         .flatMap(connectInfo -> {
           ConnectorDTO connector = connectInfo.getConnector();
-          return getConnectorTopics(clusterName, connector.getConnect(), connector.getName())
+          return getConnectorTopics(cluster, connector.getConnect(), connector.getName())
               .map(ct -> InternalConnectInfo.builder()
                   .connector(connector)
                   .config(connectInfo.getConfig())
@@ -115,9 +113,9 @@ public class KafkaConnectService {
         .map(String::toUpperCase);
   }
 
-  private Mono<ConnectorTopics> getConnectorTopics(String clusterName, String connectClusterName,
+  private Mono<ConnectorTopics> getConnectorTopics(KafkaCluster cluster, String connectClusterName,
                                                    String connectorName) {
-    return getConnectAddress(clusterName, connectClusterName)
+    return getConnectAddress(cluster, connectClusterName)
         .flatMap(connectUrl -> KafkaConnectClients
             .withBaseUrl(connectUrl)
             .getConnectorTopics(connectorName)
@@ -125,8 +123,8 @@ public class KafkaConnectService {
         );
   }
 
-  private Flux<Tuple2<String, String>> getConnectorNames(String clusterName, ConnectDTO connect) {
-    return getConnectors(clusterName, connect.getName())
+  private Flux<Tuple2<String, String>> getConnectorNames(KafkaCluster cluster, ConnectDTO connect) {
+    return getConnectors(cluster, connect.getName())
         .collectList().map(e -> e.get(0))
         // for some reason `getConnectors` method returns the response as a single string
         .map(this::parseToList)
@@ -140,30 +138,30 @@ public class KafkaConnectService {
     });
   }
 
-  public Flux<String> getConnectors(String clusterName, String connectName) {
-    return getConnectAddress(clusterName, connectName)
+  public Flux<String> getConnectors(KafkaCluster cluster, String connectName) {
+    return getConnectAddress(cluster, connectName)
         .flatMapMany(connect ->
             KafkaConnectClients.withBaseUrl(connect).getConnectors(null)
                 .doOnError(log::error)
         );
   }
 
-  public Mono<ConnectorDTO> createConnector(String clusterName, String connectName,
+  public Mono<ConnectorDTO> createConnector(KafkaCluster cluster, String connectName,
                                          Mono<NewConnectorDTO> connector) {
-    return getConnectAddress(clusterName, connectName)
+    return getConnectAddress(cluster, connectName)
         .flatMap(connect ->
             connector
                 .map(kafkaConnectMapper::toClient)
                 .flatMap(c ->
                     KafkaConnectClients.withBaseUrl(connect).createConnector(c)
                 )
-                .flatMap(c -> getConnector(clusterName, connectName, c.getName()))
+                .flatMap(c -> getConnector(cluster, connectName, c.getName()))
         );
   }
 
-  public Mono<ConnectorDTO> getConnector(String clusterName, String connectName,
+  public Mono<ConnectorDTO> getConnector(KafkaCluster cluster, String connectName,
                                       String connectorName) {
-    return getConnectAddress(clusterName, connectName)
+    return getConnectAddress(cluster, connectName)
         .flatMap(connect -> KafkaConnectClients.withBaseUrl(connect).getConnector(connectorName)
             .map(kafkaConnectMapper::fromClient)
             .flatMap(connector ->
@@ -193,17 +191,17 @@ public class KafkaConnectService {
         );
   }
 
-  public Mono<Map<String, Object>> getConnectorConfig(String clusterName, String connectName,
+  public Mono<Map<String, Object>> getConnectorConfig(KafkaCluster cluster, String connectName,
                                                       String connectorName) {
-    return getConnectAddress(clusterName, connectName)
+    return getConnectAddress(cluster, connectName)
         .flatMap(connect ->
             KafkaConnectClients.withBaseUrl(connect).getConnectorConfig(connectorName)
         );
   }
 
-  public Mono<ConnectorDTO> setConnectorConfig(String clusterName, String connectName,
+  public Mono<ConnectorDTO> setConnectorConfig(KafkaCluster cluster, String connectName,
                                             String connectorName, Mono<Object> requestBody) {
-    return getConnectAddress(clusterName, connectName)
+    return getConnectAddress(cluster, connectName)
         .flatMap(connect ->
             requestBody.flatMap(body ->
                 KafkaConnectClients.withBaseUrl(connect)
@@ -213,14 +211,15 @@ public class KafkaConnectService {
         );
   }
 
-  public Mono<Void> deleteConnector(String clusterName, String connectName, String connectorName) {
-    return getConnectAddress(clusterName, connectName)
+  public Mono<Void> deleteConnector(
+      KafkaCluster cluster, String connectName, String connectorName) {
+    return getConnectAddress(cluster, connectName)
         .flatMap(connect ->
             KafkaConnectClients.withBaseUrl(connect).deleteConnector(connectorName)
         );
   }
 
-  public Mono<Void> updateConnectorState(String clusterName, String connectName,
+  public Mono<Void> updateConnectorState(KafkaCluster cluster, String connectName,
                                          String connectorName, ConnectorActionDTO action) {
     Function<String, Mono<Void>> kafkaClientCall;
     switch (action) {
@@ -239,13 +238,13 @@ public class KafkaConnectService {
       default:
         throw new IllegalStateException("Unexpected value: " + action);
     }
-    return getConnectAddress(clusterName, connectName)
+    return getConnectAddress(cluster, connectName)
         .flatMap(kafkaClientCall);
   }
 
-  public Flux<TaskDTO> getConnectorTasks(String clusterName, String connectName,
+  public Flux<TaskDTO> getConnectorTasks(KafkaCluster cluster, String connectName,
                                       String connectorName) {
-    return getConnectAddress(clusterName, connectName)
+    return getConnectAddress(cluster, connectName)
         .flatMapMany(connect ->
             KafkaConnectClients.withBaseUrl(connect).getConnectorTasks(connectorName)
                 .map(kafkaConnectMapper::fromClient)
@@ -258,17 +257,17 @@ public class KafkaConnectService {
         );
   }
 
-  public Mono<Void> restartConnectorTask(String clusterName, String connectName,
+  public Mono<Void> restartConnectorTask(KafkaCluster cluster, String connectName,
                                          String connectorName, Integer taskId) {
-    return getConnectAddress(clusterName, connectName)
+    return getConnectAddress(cluster, connectName)
         .flatMap(connect ->
             KafkaConnectClients.withBaseUrl(connect).restartConnectorTask(connectorName, taskId)
         );
   }
 
-  public Mono<Flux<ConnectorPluginDTO>> getConnectorPlugins(String clusterName,
+  public Mono<Flux<ConnectorPluginDTO>> getConnectorPlugins(KafkaCluster cluster,
                                                             String connectName) {
-    return Mono.just(getConnectAddress(clusterName, connectName)
+    return Mono.just(getConnectAddress(cluster, connectName)
         .flatMapMany(connect ->
             KafkaConnectClients.withBaseUrl(connect).getConnectorPlugins()
                 .map(kafkaConnectMapper::fromClient)
@@ -276,8 +275,8 @@ public class KafkaConnectService {
   }
 
   public Mono<ConnectorPluginConfigValidationResponseDTO> validateConnectorPluginConfig(
-      String clusterName, String connectName, String pluginName, Mono<Object> requestBody) {
-    return getConnectAddress(clusterName, connectName)
+      KafkaCluster cluster, String connectName, String pluginName, Mono<Object> requestBody) {
+    return getConnectAddress(cluster, connectName)
         .flatMap(connect ->
             requestBody.flatMap(body ->
                 KafkaConnectClients.withBaseUrl(connect)
@@ -293,17 +292,11 @@ public class KafkaConnectService {
         .orElse(Mono.error(ClusterNotFoundException::new));
   }
 
-  private Mono<String> getConnectAddress(String clusterName, String connectName) {
-    return getCluster(clusterName)
-        .map(kafkaCluster ->
-            kafkaCluster.getKafkaConnect().stream()
-                .filter(connect -> connect.getName().equals(connectName))
-                .findFirst()
-                .map(KafkaConnectCluster::getAddress)
-        )
-        .flatMap(connect -> connect
-            .map(Mono::just)
-            .orElse(Mono.error(ConnectNotFoundException::new))
-        );
+  private Mono<String> getConnectAddress(KafkaCluster cluster, String connectName) {
+    return Mono.justOrEmpty(cluster.getKafkaConnect().stream()
+            .filter(connect -> connect.getName().equals(connectName))
+            .findFirst()
+            .map(KafkaConnectCluster::getAddress))
+        .switchIfEmpty(Mono.error(ConnectNotFoundException::new));
   }
 }

kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/KafkaService.java

@@ -1,870 +0,0 @@
-package com.provectus.kafka.ui.service;
-
-import com.provectus.kafka.ui.exception.InvalidRequestApiException;
-import com.provectus.kafka.ui.exception.LogDirNotFoundApiException;
-import com.provectus.kafka.ui.exception.TopicMetadataException;
-import com.provectus.kafka.ui.exception.TopicOrPartitionNotFoundException;
-import com.provectus.kafka.ui.exception.ValidationException;
-import com.provectus.kafka.ui.model.BrokerLogdirUpdateDTO;
-import com.provectus.kafka.ui.model.CleanupPolicy;
-import com.provectus.kafka.ui.model.CreateTopicMessageDTO;
-import com.provectus.kafka.ui.model.InternalBrokerDiskUsage;
-import com.provectus.kafka.ui.model.InternalBrokerMetrics;
-import com.provectus.kafka.ui.model.InternalClusterMetrics;
-import com.provectus.kafka.ui.model.InternalConsumerGroup;
-import com.provectus.kafka.ui.model.InternalPartition;
-import com.provectus.kafka.ui.model.InternalReplica;
-import com.provectus.kafka.ui.model.InternalSegmentSizeDto;
-import com.provectus.kafka.ui.model.InternalTopic;
-import com.provectus.kafka.ui.model.InternalTopicConfig;
-import com.provectus.kafka.ui.model.KafkaCluster;
-import com.provectus.kafka.ui.model.MetricDTO;
-import com.provectus.kafka.ui.model.PartitionsIncreaseDTO;
-import com.provectus.kafka.ui.model.ReplicationFactorChangeDTO;
-import com.provectus.kafka.ui.model.ServerStatusDTO;
-import com.provectus.kafka.ui.model.TopicCreationDTO;
-import com.provectus.kafka.ui.model.TopicUpdateDTO;
-import com.provectus.kafka.ui.serde.DeserializationService;
-import com.provectus.kafka.ui.serde.RecordSerDe;
-import com.provectus.kafka.ui.util.ClusterUtil;
-import com.provectus.kafka.ui.util.JmxClusterUtil;
-import com.provectus.kafka.ui.util.JmxMetricsName;
-import com.provectus.kafka.ui.util.JmxMetricsValueName;
-import java.math.BigDecimal;
-import java.util.ArrayList;
-import java.util.Collection;
-import java.util.Collections;
-import java.util.Comparator;
-import java.util.HashMap;
-import java.util.List;
-import java.util.LongSummaryStatistics;
-import java.util.Map;
-import java.util.Optional;
-import java.util.Properties;
-import java.util.UUID;
-import java.util.concurrent.CompletableFuture;
-import java.util.stream.Collectors;
-import lombok.RequiredArgsConstructor;
-import lombok.SneakyThrows;
-import lombok.extern.log4j.Log4j2;
-import org.apache.kafka.clients.admin.NewPartitionReassignment;
-import org.apache.kafka.clients.admin.NewPartitions;
-import org.apache.kafka.clients.consumer.ConsumerConfig;
-import org.apache.kafka.clients.consumer.KafkaConsumer;
-import org.apache.kafka.clients.producer.KafkaProducer;
-import org.apache.kafka.clients.producer.ProducerConfig;
-import org.apache.kafka.clients.producer.ProducerRecord;
-import org.apache.kafka.clients.producer.RecordMetadata;
-import org.apache.kafka.common.Node;
-import org.apache.kafka.common.TopicPartition;
-import org.apache.kafka.common.TopicPartitionReplica;
-import org.apache.kafka.common.errors.InvalidRequestException;
-import org.apache.kafka.common.errors.LogDirNotFoundException;
-import org.apache.kafka.common.errors.TimeoutException;
-import org.apache.kafka.common.errors.UnknownTopicOrPartitionException;
-import org.apache.kafka.common.header.Header;
-import org.apache.kafka.common.header.internals.RecordHeader;
-import org.apache.kafka.common.header.internals.RecordHeaders;
-import org.apache.kafka.common.requests.DescribeLogDirsResponse;
-import org.apache.kafka.common.serialization.ByteArraySerializer;
-import org.apache.kafka.common.serialization.BytesDeserializer;
-import org.apache.kafka.common.utils.Bytes;
-import org.springframework.stereotype.Service;
-import reactor.core.publisher.Flux;
-import reactor.core.publisher.Mono;
-import reactor.util.function.Tuple2;
-import reactor.util.function.Tuple3;
-import reactor.util.function.Tuples;
-
-@Service
-@RequiredArgsConstructor
-@Log4j2
-public class KafkaService {
-
-  private final ZookeeperService zookeeperService;
-  private final JmxClusterUtil jmxClusterUtil;
-  private final ClustersStorage clustersStorage;
-  private final DeserializationService deserializationService;
-  private final AdminClientService adminClientService;
-  private final FeatureService featureService;
-
-
-  public KafkaCluster getUpdatedCluster(KafkaCluster cluster, InternalTopic updatedTopic) {
-    final Map<String, InternalTopic> topics =
-        Optional.ofNullable(cluster.getTopics()).map(
-            t -> new HashMap<>(cluster.getTopics())
-        ).orElse(new HashMap<>());
-    topics.put(updatedTopic.getName(), updatedTopic);
-    return cluster.toBuilder().topics(topics).build();
-  }
-
-  public KafkaCluster getUpdatedCluster(KafkaCluster cluster, String topicToDelete) {
-    final Map<String, InternalTopic> topics = new HashMap<>(cluster.getTopics());
-    topics.remove(topicToDelete);
-    return cluster.toBuilder().topics(topics).build();
-  }
-
-  @SneakyThrows
-  public Mono<KafkaCluster> getUpdatedCluster(KafkaCluster cluster) {
-    return adminClientService.get(cluster)
-        .flatMap(
-            ac -> ac.getClusterVersion().flatMap(
-                version ->
-                    getClusterMetrics(ac)
-                        .flatMap(i -> fillJmxMetrics(i, cluster.getName(), ac))
-                        .flatMap(clusterMetrics ->
-                            getTopicsData(ac).flatMap(it -> {
-                                  if (cluster.getDisableLogDirsCollection() == null
-                                      || !cluster.getDisableLogDirsCollection()) {
-                                    return updateSegmentMetrics(ac, clusterMetrics, it
-                                    );
-                                  } else {
-                                    return emptySegmentMetrics(clusterMetrics, it);
-                                  }
-                                }
-                            ).map(segmentSizeDto -> buildFromData(cluster, version, segmentSizeDto))
-                        )
-            )
-        ).flatMap(
-            nc ->  featureService.getAvailableFeatures(cluster).collectList()
-                .map(f -> nc.toBuilder().features(f).build())
-        ).doOnError(e ->
-            log.error("Failed to collect cluster {} info", cluster.getName(), e)
-        ).onErrorResume(
-            e -> Mono.just(cluster.toBuilder()
-                .status(ServerStatusDTO.OFFLINE)
-                .lastKafkaException(e)
-                .build())
-        );
-  }
-
-  private KafkaCluster buildFromData(KafkaCluster currentCluster,
-                                     String version,
-                                     InternalSegmentSizeDto segmentSizeDto) {
-
-    var topics = segmentSizeDto.getInternalTopicWithSegmentSize();
-    var brokersMetrics = segmentSizeDto.getClusterMetricsWithSegmentSize();
-    var brokersIds = new ArrayList<>(brokersMetrics.getInternalBrokerMetrics().keySet());
-
-    InternalClusterMetrics.InternalClusterMetricsBuilder metricsBuilder =
-        brokersMetrics.toBuilder();
-
-    InternalClusterMetrics topicsMetrics = collectTopicsMetrics(topics);
-
-    ServerStatusDTO zookeeperStatus = ServerStatusDTO.OFFLINE;
-    Throwable zookeeperException = null;
-    try {
-      zookeeperStatus = zookeeperService.isZookeeperOnline(currentCluster)
-          ? ServerStatusDTO.ONLINE
-          : ServerStatusDTO.OFFLINE;
-    } catch (Throwable e) {
-      zookeeperException = e;
-    }
-
-    InternalClusterMetrics clusterMetrics = metricsBuilder
-        .activeControllers(brokersMetrics.getActiveControllers())
-        .topicCount(topicsMetrics.getTopicCount())
-        .brokerCount(brokersMetrics.getBrokerCount())
-        .underReplicatedPartitionCount(topicsMetrics.getUnderReplicatedPartitionCount())
-        .inSyncReplicasCount(topicsMetrics.getInSyncReplicasCount())
-        .outOfSyncReplicasCount(topicsMetrics.getOutOfSyncReplicasCount())
-        .onlinePartitionCount(topicsMetrics.getOnlinePartitionCount())
-        .offlinePartitionCount(topicsMetrics.getOfflinePartitionCount())
-        .zooKeeperStatus(ClusterUtil.convertToIntServerStatus(zookeeperStatus))
-        .version(version)
-        .build();
-
-    return currentCluster.toBuilder()
-        .version(version)
-        .status(ServerStatusDTO.ONLINE)
-        .zookeeperStatus(zookeeperStatus)
-        .lastZookeeperException(zookeeperException)
-        .lastKafkaException(null)
-        .metrics(clusterMetrics)
-        .topics(topics)
-        .brokers(brokersIds)
-        .build();
-  }
-
-  private InternalClusterMetrics collectTopicsMetrics(Map<String, InternalTopic> topics) {
-
-    int underReplicatedPartitions = 0;
-    int inSyncReplicasCount = 0;
-    int outOfSyncReplicasCount = 0;
-    int onlinePartitionCount = 0;
-    int offlinePartitionCount = 0;
-
-    for (InternalTopic topic : topics.values()) {
-      underReplicatedPartitions += topic.getUnderReplicatedPartitions();
-      inSyncReplicasCount += topic.getInSyncReplicas();
-      outOfSyncReplicasCount += (topic.getReplicas() - topic.getInSyncReplicas());
-      onlinePartitionCount +=
-          topic.getPartitions().values().stream().mapToInt(s -> s.getLeader() == null ? 0 : 1)
-              .sum();
-      offlinePartitionCount +=
-          topic.getPartitions().values().stream().mapToInt(s -> s.getLeader() != null ? 0 : 1)
-              .sum();
-    }
-
-    return InternalClusterMetrics.builder()
-        .underReplicatedPartitionCount(underReplicatedPartitions)
-        .inSyncReplicasCount(inSyncReplicasCount)
-        .outOfSyncReplicasCount(outOfSyncReplicasCount)
-        .onlinePartitionCount(onlinePartitionCount)
-        .offlinePartitionCount(offlinePartitionCount)
-        .topicCount(topics.size())
-        .build();
-  }
-
-  private Map<String, InternalTopic> mergeWithConfigs(
-      List<InternalTopic> topics, Map<String, List<InternalTopicConfig>> configs) {
-    return topics.stream()
-        .map(t -> t.toBuilder().topicConfigs(configs.get(t.getName())).build())
-        .map(t -> t.toBuilder().cleanUpPolicy(
-            CleanupPolicy.fromString(t.getTopicConfigs().stream()
-                .filter(config -> config.getName().equals("cleanup.policy"))
-                .findFirst()
-                .orElseGet(() -> InternalTopicConfig.builder().value("unknown").build())
-                .getValue())).build())
-        .collect(Collectors.toMap(
-            InternalTopic::getName,
-            e -> e
-        ));
-  }
-
-  @SneakyThrows
-  private Mono<List<InternalTopic>> getTopicsData(ReactiveAdminClient client) {
-    return client.listTopics(true)
-        .flatMap(topics -> getTopicsData(client, topics).collectList());
-  }
-
-  private Flux<InternalTopic> getTopicsData(ReactiveAdminClient client, Collection<String> topics) {
-    final Mono<Map<String, List<InternalTopicConfig>>> configsMono =
-        loadTopicsConfig(client, topics);
-
-    return client.describeTopics(topics)
-        .map(m -> m.values().stream()
-            .map(ClusterUtil::mapToInternalTopic).collect(Collectors.toList()))
-        .flatMap(internalTopics -> configsMono
-            .map(configs -> mergeWithConfigs(internalTopics, configs).values()))
-        .flatMapMany(Flux::fromIterable);
-  }
-
-
-  private Mono<InternalClusterMetrics> getClusterMetrics(ReactiveAdminClient client) {
-    return client.describeCluster().map(desc ->
-        InternalClusterMetrics.builder()
-            .brokerCount(desc.getNodes().size())
-            .activeControllers(desc.getController() != null ? 1 : 0)
-            .build()
-    );
-  }
-
-  @SneakyThrows
-  public Mono<InternalTopic> createTopic(ReactiveAdminClient adminClient,
-                                         Mono<TopicCreationDTO> topicCreation) {
-    return topicCreation.flatMap(topicData ->
-            adminClient.createTopic(
-                topicData.getName(),
-                topicData.getPartitions(),
-                topicData.getReplicationFactor().shortValue(),
-                topicData.getConfigs()
-            ).thenReturn(topicData)
-        )
-        .onErrorResume(t -> Mono.error(new TopicMetadataException(t.getMessage())))
-        .flatMap(topicData -> getUpdatedTopic(adminClient, topicData.getName()))
-        .switchIfEmpty(Mono.error(new RuntimeException("Can't find created topic")));
-  }
-
-  public Mono<InternalTopic> createTopic(
-      KafkaCluster cluster, Mono<TopicCreationDTO> topicCreation) {
-    return adminClientService.get(cluster).flatMap(ac -> createTopic(ac, topicCreation));
-  }
-
-  public Mono<Void> deleteTopic(KafkaCluster cluster, String topicName) {
-    return adminClientService.get(cluster).flatMap(c -> c.deleteTopic(topicName));
-  }
-
-  @SneakyThrows
-  private Mono<Map<String, List<InternalTopicConfig>>> loadTopicsConfig(
-      ReactiveAdminClient client, Collection<String> topicNames) {
-    return client.getTopicsConfig(topicNames)
-        .map(configs ->
-            configs.entrySet().stream().collect(Collectors.toMap(
-                Map.Entry::getKey,
-                c -> c.getValue().stream()
-                    .map(ClusterUtil::mapToInternalTopicConfig)
-                    .collect(Collectors.toList()))));
-  }
-
-  public Mono<List<InternalConsumerGroup>> getConsumerGroupsInternal(KafkaCluster cluster) {
-    return adminClientService.get(cluster).flatMap(ac ->
-        ac.listConsumerGroups()
-            .flatMap(groupIds -> getConsumerGroupsInternal(cluster, groupIds)));
-  }
-
-  public Mono<List<InternalConsumerGroup>> getConsumerGroupsInternal(KafkaCluster cluster,
-                                                                     List<String> groupIds) {
-    return adminClientService.get(cluster).flatMap(ac ->
-        ac.describeConsumerGroups(groupIds)
-            .map(Map::values)
-            .flatMap(descriptions ->
-                Flux.fromIterable(descriptions)
-                    .parallel()
-                    .flatMap(d ->
-                        ac.listConsumerGroupOffsets(d.groupId())
-                            .map(offsets -> ClusterUtil.convertToInternalConsumerGroup(d, offsets))
-                    )
-                    .sequential()
-                    .collectList()));
-  }
-
-  public Mono<List<InternalConsumerGroup>> getConsumerGroups(
-      KafkaCluster cluster, Optional<String> topic, List<String> groupIds) {
-    final Mono<List<InternalConsumerGroup>> consumerGroups;
-
-    if (groupIds.isEmpty()) {
-      consumerGroups = getConsumerGroupsInternal(cluster);
-    } else {
-      consumerGroups = getConsumerGroupsInternal(cluster, groupIds);
-    }
-
-    return consumerGroups.map(c ->
-        c.stream()
-            .map(d -> ClusterUtil.filterConsumerGroupTopic(d, topic))
-            .filter(Optional::isPresent)
-            .map(Optional::get)
-            .map(g ->
-                g.toBuilder().endOffsets(
-                    topicPartitionsEndOffsets(cluster, g.getOffsets().keySet())
-                ).build()
-            )
-            .collect(Collectors.toList())
-    );
-  }
-
-  public Map<TopicPartition, Long> topicPartitionsEndOffsets(
-      KafkaCluster cluster, Collection<TopicPartition> topicPartitions) {
-    try (KafkaConsumer<Bytes, Bytes> consumer = createConsumer(cluster)) {
-      return consumer.endOffsets(topicPartitions);
-    }
-  }
-
-  public KafkaConsumer<Bytes, Bytes> createConsumer(KafkaCluster cluster) {
-    return createConsumer(cluster, Map.of());
-  }
-
-  public KafkaConsumer<Bytes, Bytes> createConsumer(KafkaCluster cluster,
-                                                    Map<String, Object> properties) {
-    Properties props = new Properties();
-    props.putAll(cluster.getProperties());
-    props.put(ConsumerConfig.CLIENT_ID_CONFIG, "kafka-ui-" + UUID.randomUUID());
-    props.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, cluster.getBootstrapServers());
-    props.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, BytesDeserializer.class);
-    props.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, BytesDeserializer.class);
-    props.put(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG, "earliest");
-    props.putAll(properties);
-
-    return new KafkaConsumer<>(props);
-  }
-
-  @SneakyThrows
-  public Mono<InternalTopic> updateTopic(KafkaCluster cluster,
-                                         String topicName,
-                                         TopicUpdateDTO topicUpdate) {
-    return adminClientService.get(cluster)
-        .flatMap(ac ->
-            ac.updateTopicConfig(topicName,
-                topicUpdate.getConfigs()).then(getUpdatedTopic(ac, topicName)));
-  }
-
-  private Mono<InternalTopic> getUpdatedTopic(ReactiveAdminClient ac, String topicName) {
-    return getTopicsData(ac, List.of(topicName)).next();
-  }
-
-  private InternalTopic mergeWithStats(InternalTopic topic,
-                                       Map<String, LongSummaryStatistics> topics,
-                                       Map<TopicPartition, LongSummaryStatistics> partitions) {
-    final LongSummaryStatistics stats = topics.get(topic.getName());
-
-    return topic.toBuilder()
-        .segmentSize(stats.getSum())
-        .segmentCount(stats.getCount())
-        .partitions(
-            topic.getPartitions().entrySet().stream().map(e ->
-                Tuples.of(e.getKey(), mergeWithStats(topic.getName(), e.getValue(), partitions))
-            ).collect(Collectors.toMap(
-                Tuple2::getT1,
-                Tuple2::getT2
-            ))
-        ).build();
-  }
-
-  private InternalPartition mergeWithStats(String topic, InternalPartition partition,
-                                           Map<TopicPartition, LongSummaryStatistics> partitions) {
-    final LongSummaryStatistics stats =
-        partitions.get(new TopicPartition(topic, partition.getPartition()));
-    return partition.toBuilder()
-        .segmentSize(stats.getSum())
-        .segmentCount(stats.getCount())
-        .build();
-  }
-
-  private Mono<InternalSegmentSizeDto> emptySegmentMetrics(InternalClusterMetrics clusterMetrics,
-                                                            List<InternalTopic> internalTopics) {
-    return Mono.just(
-        InternalSegmentSizeDto.builder()
-        .clusterMetricsWithSegmentSize(
-            clusterMetrics.toBuilder()
-                .segmentSize(0)
-                .segmentCount(0)
-                .internalBrokerDiskUsage(Collections.emptyMap())
-                .build()
-        )
-        .internalTopicWithSegmentSize(
-            internalTopics.stream().collect(
-                Collectors.toMap(
-                    InternalTopic::getName,
-                    i -> i
-                )
-            )
-        ).build()
-    );
-  }
-
-  private Mono<InternalSegmentSizeDto> updateSegmentMetrics(ReactiveAdminClient ac,
-                                                            InternalClusterMetrics clusterMetrics,
-                                                            List<InternalTopic> internalTopics) {
-    return ac.describeCluster().flatMap(
-        clusterDescription ->
-                ac.describeLogDirs().map(log -> {
-                  final List<Tuple3<Integer, TopicPartition, Long>> topicPartitions =
-                      log.entrySet().stream().flatMap(b ->
-                          b.getValue().entrySet().stream().flatMap(topicMap ->
-                              topicMap.getValue().replicaInfos.entrySet().stream()
-                                  .map(e -> Tuples.of(b.getKey(), e.getKey(), e.getValue().size))
-                          )
-                      ).collect(Collectors.toList());
-
-                  final Map<TopicPartition, LongSummaryStatistics> partitionStats =
-                      topicPartitions.stream().collect(
-                          Collectors.groupingBy(
-                              Tuple2::getT2,
-                              Collectors.summarizingLong(Tuple3::getT3)
-                          )
-                      );
-
-                  final Map<String, LongSummaryStatistics> topicStats =
-                      topicPartitions.stream().collect(
-                          Collectors.groupingBy(
-                              t -> t.getT2().topic(),
-                              Collectors.summarizingLong(Tuple3::getT3)
-                          )
-                      );
-
-                  final Map<Integer, LongSummaryStatistics> brokerStats =
-                      topicPartitions.stream().collect(
-                          Collectors.groupingBy(
-                              Tuple2::getT1,
-                              Collectors.summarizingLong(Tuple3::getT3)
-                          )
-                      );
-
-
-                  final LongSummaryStatistics summary =
-                      topicPartitions.stream().collect(Collectors.summarizingLong(Tuple3::getT3));
-
-
-                  final Map<String, InternalTopic> resultTopics = internalTopics.stream().map(e ->
-                      Tuples.of(e.getName(), mergeWithStats(e, topicStats, partitionStats))
-                  ).collect(Collectors.toMap(
-                      Tuple2::getT1,
-                      Tuple2::getT2
-                  ));
-
-                  final Map<Integer, InternalBrokerDiskUsage> resultBrokers =
-                      brokerStats.entrySet().stream().map(e ->
-                          Tuples.of(e.getKey(), InternalBrokerDiskUsage.builder()
-                              .segmentSize(e.getValue().getSum())
-                              .segmentCount(e.getValue().getCount())
-                              .build()
-                          )
-                      ).collect(Collectors.toMap(
-                          Tuple2::getT1,
-                          Tuple2::getT2
-                      ));
-
-                  return InternalSegmentSizeDto.builder()
-                      .clusterMetricsWithSegmentSize(
-                          clusterMetrics.toBuilder()
-                              .segmentSize(summary.getSum())
-                              .segmentCount(summary.getCount())
-                              .internalBrokerDiskUsage(resultBrokers)
-                              .build()
-                      )
-                      .internalTopicWithSegmentSize(resultTopics).build();
-                })
-    );
-  }
-
-  public List<MetricDTO> getJmxMetric(String clusterName, Node node) {
-    return clustersStorage.getClusterByName(clusterName)
-        .filter(c -> c.getJmxPort() != null)
-        .filter(c -> c.getJmxPort() > 0)
-        .map(c -> jmxClusterUtil.getJmxMetrics(node.host(), c.getJmxPort(), c.isJmxSsl(),
-                c.getJmxUsername(), c.getJmxPassword()))
-        .orElse(Collections.emptyList());
-  }
-
-  private Mono<InternalClusterMetrics> fillJmxMetrics(InternalClusterMetrics internalClusterMetrics,
-                                                      String clusterName, ReactiveAdminClient ac) {
-    return fillBrokerMetrics(internalClusterMetrics, clusterName, ac)
-        .map(this::calculateClusterMetrics);
-  }
-
-  private Mono<InternalClusterMetrics> fillBrokerMetrics(
-      InternalClusterMetrics internalClusterMetrics, String clusterName, ReactiveAdminClient ac) {
-    return ac.describeCluster()
-        .flatMapIterable(desc -> desc.getNodes())
-        .map(broker ->
-            Map.of(broker.id(), InternalBrokerMetrics.builder()
-                .metrics(getJmxMetric(clusterName, broker)).build())
-        )
-        .collectList()
-        .map(s -> internalClusterMetrics.toBuilder()
-            .internalBrokerMetrics(ClusterUtil.toSingleMap(s.stream())).build());
-  }
-
-  private InternalClusterMetrics calculateClusterMetrics(
-      InternalClusterMetrics internalClusterMetrics) {
-    final List<MetricDTO> metrics = internalClusterMetrics.getInternalBrokerMetrics().values()
-        .stream()
-        .flatMap(b -> b.getMetrics().stream())
-        .collect(
-            Collectors.groupingBy(
-                MetricDTO::getCanonicalName,
-                Collectors.reducing(jmxClusterUtil::reduceJmxMetrics)
-            )
-        ).values().stream()
-        .filter(Optional::isPresent)
-        .map(Optional::get)
-        .collect(Collectors.toList());
-    final InternalClusterMetrics.InternalClusterMetricsBuilder metricsBuilder =
-        internalClusterMetrics.toBuilder().metrics(metrics);
-    metricsBuilder.bytesInPerSec(findTopicMetrics(
-        metrics, JmxMetricsName.BytesInPerSec, JmxMetricsValueName.FiveMinuteRate
-    ));
-    metricsBuilder.bytesOutPerSec(findTopicMetrics(
-        metrics, JmxMetricsName.BytesOutPerSec, JmxMetricsValueName.FiveMinuteRate
-    ));
-    return metricsBuilder.build();
-  }
-
-  private Map<String, BigDecimal> findTopicMetrics(List<MetricDTO> metrics,
-                                                   JmxMetricsName metricsName,
-                                                   JmxMetricsValueName valueName) {
-    return metrics.stream().filter(m -> metricsName.name().equals(m.getName()))
-        .filter(m -> m.getParams().containsKey("topic"))
-        .filter(m -> m.getValue().containsKey(valueName.name()))
-        .map(m -> Tuples.of(
-            m.getParams().get("topic"),
-            m.getValue().get(valueName.name())
-        )).collect(Collectors.groupingBy(
-            Tuple2::getT1,
-            Collectors.reducing(BigDecimal.ZERO, Tuple2::getT2, BigDecimal::add)
-        ));
-  }
-
-  public Map<Integer, InternalPartition> getTopicPartitions(KafkaCluster c, InternalTopic topic) {
-    var tps = topic.getPartitions().values().stream()
-        .map(t -> new TopicPartition(topic.getName(), t.getPartition()))
-        .collect(Collectors.toList());
-    Map<Integer, InternalPartition> partitions =
-        topic.getPartitions().values().stream().collect(Collectors.toMap(
-            InternalPartition::getPartition,
-            tp -> tp
-        ));
-
-    try (var consumer = createConsumer(c)) {
-      final Map<TopicPartition, Long> earliest = consumer.beginningOffsets(tps);
-      final Map<TopicPartition, Long> latest = consumer.endOffsets(tps);
-
-      return tps.stream()
-          .map(tp -> partitions.get(tp.partition()).toBuilder()
-              .offsetMin(Optional.ofNullable(earliest.get(tp)).orElse(0L))
-              .offsetMax(Optional.ofNullable(latest.get(tp)).orElse(0L))
-              .build()
-          ).collect(Collectors.toMap(
-              InternalPartition::getPartition,
-              tp -> tp
-          ));
-    } catch (Exception e) {
-      return Collections.emptyMap();
-    }
-  }
-
-  public Mono<Void> deleteTopicMessages(KafkaCluster cluster, Map<TopicPartition, Long> offsets) {
-    return adminClientService.get(cluster).flatMap(ac -> ac.deleteRecords(offsets));
-  }
-
-  public Mono<RecordMetadata> sendMessage(KafkaCluster cluster, String topic,
-                                          CreateTopicMessageDTO msg) {
-    RecordSerDe serde =
-        deserializationService.getRecordDeserializerForCluster(cluster);
-
-    Properties properties = new Properties();
-    properties.putAll(cluster.getProperties());
-    properties.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, cluster.getBootstrapServers());
-    properties.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, ByteArraySerializer.class);
-    properties.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, ByteArraySerializer.class);
-    try (KafkaProducer<byte[], byte[]> producer = new KafkaProducer<>(properties)) {
-      ProducerRecord<byte[], byte[]> producerRecord = serde.serialize(
-          topic,
-          msg.getKey(),
-          msg.getContent(),
-          msg.getPartition()
-      );
-      producerRecord = new ProducerRecord<>(
-          producerRecord.topic(),
-          producerRecord.partition(),
-          producerRecord.key(),
-          producerRecord.value(),
-          createHeaders(msg.getHeaders()));
-
-      CompletableFuture<RecordMetadata> cf = new CompletableFuture<>();
-      producer.send(producerRecord, (metadata, exception) -> {
-        if (exception != null) {
-          cf.completeExceptionally(exception);
-        } else {
-          cf.complete(metadata);
-        }
-      });
-      return Mono.fromFuture(cf);
-    }
-  }
-
-  private Iterable<Header> createHeaders(Map<String, String> clientHeaders) {
-    if (clientHeaders == null) {
-      return null;
-    }
-    RecordHeaders headers = new RecordHeaders();
-    clientHeaders.forEach((k, v) -> headers.add(new RecordHeader(k, v.getBytes())));
-    return headers;
-  }
-
-  public Mono<InternalTopic> increaseTopicPartitions(
-      KafkaCluster cluster,
-      String topicName,
-      PartitionsIncreaseDTO partitionsIncrease) {
-    return adminClientService.get(cluster)
-        .flatMap(ac -> {
-          Integer actualCount = cluster.getTopics().get(topicName).getPartitionCount();
-          Integer requestedCount = partitionsIncrease.getTotalPartitionsCount();
-
-          if (requestedCount < actualCount) {
-            return Mono.error(
-                new ValidationException(String.format(
-                    "Topic currently has %s partitions, which is higher than the requested %s.",
-                    actualCount, requestedCount)));
-          }
-          if (requestedCount.equals(actualCount)) {
-            return Mono.error(
-                new ValidationException(
-                    String.format("Topic already has %s partitions.", actualCount)));
-          }
-
-          Map<String, NewPartitions> newPartitionsMap = Collections.singletonMap(
-              topicName,
-              NewPartitions.increaseTo(partitionsIncrease.getTotalPartitionsCount())
-          );
-          return ac.createPartitions(newPartitionsMap)
-              .then(getUpdatedTopic(ac, topicName));
-        });
-  }
-
-  private Mono<InternalTopic> changeReplicationFactor(
-      ReactiveAdminClient adminClient,
-      String topicName,
-      Map<TopicPartition, Optional<NewPartitionReassignment>> reassignments
-  ) {
-    return adminClient.alterPartitionReassignments(reassignments)
-        .then(getUpdatedTopic(adminClient, topicName));
-  }
-
-  /**
-   * Change topic replication factor, works on brokers versions 5.4.x and higher
-   */
-  public Mono<InternalTopic> changeReplicationFactor(
-      KafkaCluster cluster,
-      String topicName,
-      ReplicationFactorChangeDTO replicationFactorChange) {
-    return adminClientService.get(cluster)
-        .flatMap(ac -> {
-          Integer actual = cluster.getTopics().get(topicName).getReplicationFactor();
-          Integer requested = replicationFactorChange.getTotalReplicationFactor();
-          Integer brokersCount = cluster.getMetrics().getBrokerCount();
-
-          if (requested.equals(actual)) {
-            return Mono.error(
-                new ValidationException(
-                    String.format("Topic already has replicationFactor %s.", actual)));
-          }
-          if (requested > brokersCount) {
-            return Mono.error(
-                new ValidationException(
-                    String.format("Requested replication factor %s more than brokers count %s.",
-                        requested, brokersCount)));
-          }
-          return changeReplicationFactor(ac, topicName,
-              getPartitionsReassignments(cluster, topicName,
-                  replicationFactorChange));
-        });
-  }
-
-  public Mono<Map<Integer, Map<String, DescribeLogDirsResponse.LogDirInfo>>> getClusterLogDirs(
-      KafkaCluster cluster, List<Integer> reqBrokers) {
-    return adminClientService.get(cluster)
-        .flatMap(admin -> {
-          List<Integer> brokers = new ArrayList<>(cluster.getBrokers());
-          if (reqBrokers != null && !reqBrokers.isEmpty()) {
-            brokers.retainAll(reqBrokers);
-          }
-          return admin.describeLogDirs(brokers);
-        })
-        .onErrorResume(TimeoutException.class, (TimeoutException e) -> {
-          log.error("Error during fetching log dirs", e);
-          return Mono.just(new HashMap<>());
-        });
-  }
-
-  private Map<TopicPartition, Optional<NewPartitionReassignment>> getPartitionsReassignments(
-      KafkaCluster cluster,
-      String topicName,
-      ReplicationFactorChangeDTO replicationFactorChange) {
-    // Current assignment map (Partition number -> List of brokers)
-    Map<Integer, List<Integer>> currentAssignment = getCurrentAssignment(cluster, topicName);
-    // Brokers map (Broker id -> count)
-    Map<Integer, Integer> brokersUsage = getBrokersMap(cluster, currentAssignment);
-    int currentReplicationFactor = cluster.getTopics().get(topicName).getReplicationFactor();
-
-    // If we should to increase Replication factor
-    if (replicationFactorChange.getTotalReplicationFactor() > currentReplicationFactor) {
-      // For each partition
-      for (var assignmentList : currentAssignment.values()) {
-        // Get brokers list sorted by usage
-        var brokers = brokersUsage.entrySet().stream()
-            .sorted(Map.Entry.comparingByValue())
-            .map(Map.Entry::getKey)
-            .collect(Collectors.toList());
-
-        // Iterate brokers and try to add them in assignment
-        // while (partition replicas count != requested replication factor)
-        for (Integer broker : brokers) {
-          if (!assignmentList.contains(broker)) {
-            assignmentList.add(broker);
-            brokersUsage.merge(broker, 1, Integer::sum);
-          }
-          if (assignmentList.size() == replicationFactorChange.getTotalReplicationFactor()) {
-            break;
-          }
-        }
-        if (assignmentList.size() != replicationFactorChange.getTotalReplicationFactor()) {
-          throw new ValidationException("Something went wrong during adding replicas");
-        }
-      }
-
-      // If we should to decrease Replication factor
-    } else if (replicationFactorChange.getTotalReplicationFactor() < currentReplicationFactor) {
-      for (Map.Entry<Integer, List<Integer>> assignmentEntry : currentAssignment.entrySet()) {
-        var partition = assignmentEntry.getKey();
-        var brokers = assignmentEntry.getValue();
-
-        // Get brokers list sorted by usage in reverse order
-        var brokersUsageList = brokersUsage.entrySet().stream()
-            .sorted(Map.Entry.comparingByValue(Comparator.reverseOrder()))
-            .map(Map.Entry::getKey)
-            .collect(Collectors.toList());
-
-        // Iterate brokers and try to remove them from assignment
-        // while (partition replicas count != requested replication factor)
-        for (Integer broker : brokersUsageList) {
-          // Check is the broker the leader of partition
-          if (!cluster.getTopics().get(topicName).getPartitions().get(partition).getLeader()
-              .equals(broker)) {
-            brokers.remove(broker);
-            brokersUsage.merge(broker, -1, Integer::sum);
-          }
-          if (brokers.size() == replicationFactorChange.getTotalReplicationFactor()) {
-            break;
-          }
-        }
-        if (brokers.size() != replicationFactorChange.getTotalReplicationFactor()) {
-          throw new ValidationException("Something went wrong during removing replicas");
-        }
-      }
-    } else {
-      throw new ValidationException("Replication factor already equals requested");
-    }
-
-    // Return result map
-    return currentAssignment.entrySet().stream().collect(Collectors.toMap(
-        e -> new TopicPartition(topicName, e.getKey()),
-        e -> Optional.of(new NewPartitionReassignment(e.getValue()))
-    ));
-  }
-
-  private Map<Integer, List<Integer>> getCurrentAssignment(KafkaCluster cluster, String topicName) {
-    return cluster.getTopics().get(topicName).getPartitions().values().stream()
-        .collect(Collectors.toMap(
-            InternalPartition::getPartition,
-            p -> p.getReplicas().stream()
-                .map(InternalReplica::getBroker)
-                .collect(Collectors.toList())
-        ));
-  }
-
-  private Map<Integer, Integer> getBrokersMap(KafkaCluster cluster,
-                                              Map<Integer, List<Integer>> currentAssignment) {
-    Map<Integer, Integer> result = cluster.getBrokers().stream()
-        .collect(Collectors.toMap(
-            c -> c,
-            c -> 0
-        ));
-    currentAssignment.values().forEach(brokers -> brokers
-        .forEach(broker -> result.put(broker, result.get(broker) + 1)));
-
-    return result;
-  }
-
-  public Mono<Void> updateBrokerLogDir(KafkaCluster cluster, Integer broker,
-                                       BrokerLogdirUpdateDTO brokerLogDir) {
-    return adminClientService.get(cluster)
-        .flatMap(ac -> updateBrokerLogDir(ac, brokerLogDir, broker));
-  }
-
-  private Mono<Void> updateBrokerLogDir(ReactiveAdminClient admin,
-                                        BrokerLogdirUpdateDTO b,
-                                        Integer broker) {
-
-    Map<TopicPartitionReplica, String> req = Map.of(
-        new TopicPartitionReplica(b.getTopic(), b.getPartition(), broker),
-        b.getLogDir());
-    return  admin.alterReplicaLogDirs(req)
-        .onErrorResume(UnknownTopicOrPartitionException.class,
-            e -> Mono.error(new TopicOrPartitionNotFoundException()))
-        .onErrorResume(LogDirNotFoundException.class,
-            e -> Mono.error(new LogDirNotFoundApiException()))
-        .doOnError(log::error);
-  }
-
-  public Mono<Void> updateBrokerConfigByName(KafkaCluster cluster,
-                                             Integer broker,
-                                             String name,
-                                             String value) {
-    return adminClientService.get(cluster)
-        .flatMap(ac -> ac.updateBrokerConfigByName(broker, name, value))
-        .onErrorResume(InvalidRequestException.class,
-            e -> Mono.error(new InvalidRequestApiException(e.getMessage())))
-        .doOnError(log::error);
-  }
-}

kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/KsqlService.java

@@ -17,13 +17,11 @@ import reactor.core.publisher.Mono;
 @RequiredArgsConstructor
 public class KsqlService {
   private final KsqlClient ksqlClient;
-  private final ClustersStorage clustersStorage;
   private final List<BaseStrategy> ksqlStatementStrategies;
 
-  public Mono<KsqlCommandResponseDTO> executeKsqlCommand(String clusterName,
+  public Mono<KsqlCommandResponseDTO> executeKsqlCommand(KafkaCluster cluster,
                                                       Mono<KsqlCommandDTO> ksqlCommand) {
-    return Mono.justOrEmpty(clustersStorage.getClusterByName(clusterName))
-        .switchIfEmpty(Mono.error(ClusterNotFoundException::new))
+    return Mono.justOrEmpty(cluster)
         .map(KafkaCluster::getKsqldbServer)
         .onErrorResume(e -> {
           Throwable throwable =

kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/MessagesService.java

@@ -0,0 +1,193 @@
+package com.provectus.kafka.ui.service;
+
+import com.provectus.kafka.ui.emitter.BackwardRecordEmitter;
+import com.provectus.kafka.ui.emitter.ForwardRecordEmitter;
+import com.provectus.kafka.ui.exception.TopicNotFoundException;
+import com.provectus.kafka.ui.exception.ValidationException;
+import com.provectus.kafka.ui.model.ConsumerPosition;
+import com.provectus.kafka.ui.model.CreateTopicMessageDTO;
+import com.provectus.kafka.ui.model.KafkaCluster;
+import com.provectus.kafka.ui.model.SeekDirectionDTO;
+import com.provectus.kafka.ui.model.TopicMessageDTO;
+import com.provectus.kafka.ui.model.TopicMessageEventDTO;
+import com.provectus.kafka.ui.serde.DeserializationService;
+import com.provectus.kafka.ui.serde.RecordSerDe;
+import com.provectus.kafka.ui.util.FilterTopicMessageEvents;
+import com.provectus.kafka.ui.util.OffsetsSeekBackward;
+import com.provectus.kafka.ui.util.OffsetsSeekForward;
+import java.util.Collection;
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+import java.util.Properties;
+import java.util.concurrent.CompletableFuture;
+import java.util.stream.Collectors;
+import javax.annotation.Nullable;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.log4j.Log4j2;
+import org.apache.kafka.clients.consumer.Consumer;
+import org.apache.kafka.clients.consumer.KafkaConsumer;
+import org.apache.kafka.clients.producer.KafkaProducer;
+import org.apache.kafka.clients.producer.ProducerConfig;
+import org.apache.kafka.clients.producer.ProducerRecord;
+import org.apache.kafka.clients.producer.RecordMetadata;
+import org.apache.kafka.common.TopicPartition;
+import org.apache.kafka.common.header.Header;
+import org.apache.kafka.common.header.internals.RecordHeader;
+import org.apache.kafka.common.header.internals.RecordHeaders;
+import org.apache.kafka.common.serialization.ByteArraySerializer;
+import org.apache.kafka.common.utils.Bytes;
+import org.springframework.stereotype.Service;
+import org.springframework.util.StringUtils;
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.FluxSink;
+import reactor.core.publisher.Mono;
+import reactor.core.scheduler.Schedulers;
+
+@Service
+@RequiredArgsConstructor
+@Log4j2
+public class MessagesService {
+
+  private static final int MAX_LOAD_RECORD_LIMIT = 100;
+  private static final int DEFAULT_LOAD_RECORD_LIMIT = 20;
+
+  private final AdminClientService adminClientService;
+  private final DeserializationService deserializationService;
+  private final ConsumerGroupService consumerGroupService;
+
+  public Mono<Void> deleteTopicMessages(KafkaCluster cluster, String topicName,
+                                        List<Integer> partitionsToInclude) {
+    if (!cluster.getTopics().containsKey(topicName)) {
+      throw new TopicNotFoundException();
+    }
+    return offsetsForDeletion(cluster, topicName, partitionsToInclude)
+        .flatMap(offsets ->
+            adminClientService.get(cluster).flatMap(ac -> ac.deleteRecords(offsets)));
+  }
+
+  private Mono<Map<TopicPartition, Long>> offsetsForDeletion(KafkaCluster cluster, String topicName,
+                                                            List<Integer> partitionsToInclude) {
+    return Mono.fromSupplier(() -> {
+      try (KafkaConsumer<Bytes, Bytes> consumer = consumerGroupService.createConsumer(cluster)) {
+        return significantOffsets(consumer, topicName, partitionsToInclude);
+      } catch (Exception e) {
+        log.error("Error occurred while consuming records", e);
+        throw new RuntimeException(e);
+      }
+    });
+  }
+
+  public Mono<RecordMetadata> sendMessage(KafkaCluster cluster, String topic,
+                                          CreateTopicMessageDTO msg) {
+    if (msg.getKey() == null && msg.getContent() == null) {
+      throw new ValidationException("Invalid message: both key and value can't be null");
+    }
+    if (msg.getPartition() != null
+        && msg.getPartition() > cluster.getTopics().get(topic).getPartitionCount() - 1) {
+      throw new ValidationException("Invalid partition");
+    }
+    RecordSerDe serde =
+        deserializationService.getRecordDeserializerForCluster(cluster);
+
+    Properties properties = new Properties();
+    properties.putAll(cluster.getProperties());
+    properties.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, cluster.getBootstrapServers());
+    properties.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, ByteArraySerializer.class);
+    properties.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, ByteArraySerializer.class);
+    try (KafkaProducer<byte[], byte[]> producer = new KafkaProducer<>(properties)) {
+      ProducerRecord<byte[], byte[]> producerRecord = serde.serialize(
+          topic,
+          msg.getKey(),
+          msg.getContent(),
+          msg.getPartition()
+      );
+      producerRecord = new ProducerRecord<>(
+          producerRecord.topic(),
+          producerRecord.partition(),
+          producerRecord.key(),
+          producerRecord.value(),
+          createHeaders(msg.getHeaders()));
+
+      CompletableFuture<RecordMetadata> cf = new CompletableFuture<>();
+      producer.send(producerRecord, (metadata, exception) -> {
+        if (exception != null) {
+          cf.completeExceptionally(exception);
+        } else {
+          cf.complete(metadata);
+        }
+      });
+      return Mono.fromFuture(cf);
+    }
+  }
+
+  private Iterable<Header> createHeaders(@Nullable Map<String, String> clientHeaders) {
+    if (clientHeaders == null) {
+      return new RecordHeaders();
+    }
+    RecordHeaders headers = new RecordHeaders();
+    clientHeaders.forEach((k, v) -> headers.add(new RecordHeader(k, v.getBytes())));
+    return headers;
+  }
+
+  public Flux<TopicMessageEventDTO> loadMessages(KafkaCluster cluster, String topic,
+                                                 ConsumerPosition consumerPosition, String query,
+                                                 Integer limit) {
+    int recordsLimit = Optional.ofNullable(limit)
+        .map(s -> Math.min(s, MAX_LOAD_RECORD_LIMIT))
+        .orElse(DEFAULT_LOAD_RECORD_LIMIT);
+
+    java.util.function.Consumer<? super FluxSink<TopicMessageEventDTO>> emitter;
+    RecordSerDe recordDeserializer =
+        deserializationService.getRecordDeserializerForCluster(cluster);
+    if (consumerPosition.getSeekDirection().equals(SeekDirectionDTO.FORWARD)) {
+      emitter = new ForwardRecordEmitter(
+          () -> consumerGroupService.createConsumer(cluster),
+          new OffsetsSeekForward(topic, consumerPosition),
+          recordDeserializer
+      );
+    } else {
+      emitter = new BackwardRecordEmitter(
+          (Map<String, Object> props) -> consumerGroupService.createConsumer(cluster, props),
+          new OffsetsSeekBackward(topic, consumerPosition, recordsLimit),
+          recordDeserializer
+      );
+    }
+    return Flux.create(emitter)
+        .filter(m -> filterTopicMessage(m, query))
+        .takeWhile(new FilterTopicMessageEvents(recordsLimit))
+        .subscribeOn(Schedulers.elastic())
+        .share();
+  }
+
+  /**
+   * returns end offsets for partitions where start offset != end offsets.
+   * This is useful when we need to verify that partition is not empty.
+   */
+  public static Map<TopicPartition, Long> significantOffsets(Consumer<?, ?> consumer,
+                                                             String topicName,
+                                                             Collection<Integer>
+                                                                 partitionsToInclude) {
+    var partitions = consumer.partitionsFor(topicName).stream()
+        .filter(p -> partitionsToInclude.isEmpty() || partitionsToInclude.contains(p.partition()))
+        .map(p -> new TopicPartition(topicName, p.partition()))
+        .collect(Collectors.toList());
+    var beginningOffsets = consumer.beginningOffsets(partitions);
+    var endOffsets = consumer.endOffsets(partitions);
+    return endOffsets.entrySet().stream()
+        .filter(entry -> !beginningOffsets.get(entry.getKey()).equals(entry.getValue()))
+        .collect(Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue));
+  }
+
+  private boolean filterTopicMessage(TopicMessageEventDTO message, String query) {
+    if (StringUtils.isEmpty(query)
+        || !message.getType().equals(TopicMessageEventDTO.TypeEnum.MESSAGE)) {
+      return true;
+    }
+
+    final TopicMessageDTO msg = message.getMessage();
+    return (!StringUtils.isEmpty(msg.getKey()) && msg.getKey().contains(query))
+        || (!StringUtils.isEmpty(msg.getContent()) && msg.getContent().contains(query));
+  }
+
+}

kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/MetricsService.java

@@ -0,0 +1,363 @@
+package com.provectus.kafka.ui.service;
+
+import com.provectus.kafka.ui.model.InternalBrokerDiskUsage;
+import com.provectus.kafka.ui.model.InternalBrokerMetrics;
+import com.provectus.kafka.ui.model.InternalClusterMetrics;
+import com.provectus.kafka.ui.model.InternalPartition;
+import com.provectus.kafka.ui.model.InternalSegmentSizeDto;
+import com.provectus.kafka.ui.model.InternalTopic;
+import com.provectus.kafka.ui.model.KafkaCluster;
+import com.provectus.kafka.ui.model.MetricDTO;
+import com.provectus.kafka.ui.model.ServerStatusDTO;
+import com.provectus.kafka.ui.util.ClusterUtil;
+import com.provectus.kafka.ui.util.JmxClusterUtil;
+import com.provectus.kafka.ui.util.JmxMetricsName;
+import com.provectus.kafka.ui.util.JmxMetricsValueName;
+import java.math.BigDecimal;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.LongSummaryStatistics;
+import java.util.Map;
+import java.util.Optional;
+import java.util.stream.Collectors;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.log4j.Log4j2;
+import org.apache.kafka.common.Node;
+import org.apache.kafka.common.TopicPartition;
+import org.springframework.stereotype.Service;
+import reactor.core.publisher.Mono;
+import reactor.util.function.Tuple2;
+import reactor.util.function.Tuple3;
+import reactor.util.function.Tuples;
+
+@Service
+@RequiredArgsConstructor
+@Log4j2
+public class MetricsService {
+
+  private final ZookeeperService zookeeperService;
+  private final JmxClusterUtil jmxClusterUtil;
+  private final AdminClientService adminClientService;
+  private final FeatureService featureService;
+  private final TopicsService topicsService;
+
+  /**
+   * Updates cluster's metrics and topics structure.
+   * @param cluster to be updated
+   * @return cluster with up-to-date metrics and topics structure
+   */
+  public Mono<KafkaCluster> updateClusterMetrics(KafkaCluster cluster) {
+    return adminClientService.get(cluster)
+        .flatMap(
+            ac -> ac.getClusterVersion().flatMap(
+                version ->
+                    getClusterMetrics(ac)
+                        .flatMap(i -> fillJmxMetrics(i, cluster, ac))
+                        .flatMap(clusterMetrics ->
+                            topicsService.getTopicsData(ac).flatMap(it -> {
+                                  if (cluster.getDisableLogDirsCollection() == null
+                                      || !cluster.getDisableLogDirsCollection()) {
+                                    return updateSegmentMetrics(ac, clusterMetrics, it
+                                    );
+                                  } else {
+                                    return emptySegmentMetrics(clusterMetrics, it);
+                                  }
+                                }
+                            ).map(segmentSizeDto -> buildFromData(cluster, version, segmentSizeDto))
+                        )
+            )
+        ).flatMap(
+            nc -> featureService.getAvailableFeatures(cluster).collectList()
+                .map(f -> nc.toBuilder().features(f).build())
+        ).doOnError(e ->
+            log.error("Failed to collect cluster {} info", cluster.getName(), e)
+        ).onErrorResume(
+            e -> Mono.just(cluster.toBuilder()
+                .status(ServerStatusDTO.OFFLINE)
+                .lastKafkaException(e)
+                .build())
+        );
+  }
+
+  private KafkaCluster buildFromData(KafkaCluster currentCluster,
+                                     String version,
+                                     InternalSegmentSizeDto segmentSizeDto) {
+
+    var topics = segmentSizeDto.getInternalTopicWithSegmentSize();
+    var brokersMetrics = segmentSizeDto.getClusterMetricsWithSegmentSize();
+    var brokersIds = new ArrayList<>(brokersMetrics.getInternalBrokerMetrics().keySet());
+
+    InternalClusterMetrics.InternalClusterMetricsBuilder metricsBuilder =
+        brokersMetrics.toBuilder();
+
+    InternalClusterMetrics topicsMetrics = collectTopicsMetrics(topics);
+
+    ServerStatusDTO zookeeperStatus = ServerStatusDTO.OFFLINE;
+    Throwable zookeeperException = null;
+    try {
+      zookeeperStatus = zookeeperService.isZookeeperOnline(currentCluster)
+          ? ServerStatusDTO.ONLINE
+          : ServerStatusDTO.OFFLINE;
+    } catch (Throwable e) {
+      zookeeperException = e;
+    }
+
+    InternalClusterMetrics clusterMetrics = metricsBuilder
+        .activeControllers(brokersMetrics.getActiveControllers())
+        .topicCount(topicsMetrics.getTopicCount())
+        .brokerCount(brokersMetrics.getBrokerCount())
+        .underReplicatedPartitionCount(topicsMetrics.getUnderReplicatedPartitionCount())
+        .inSyncReplicasCount(topicsMetrics.getInSyncReplicasCount())
+        .outOfSyncReplicasCount(topicsMetrics.getOutOfSyncReplicasCount())
+        .onlinePartitionCount(topicsMetrics.getOnlinePartitionCount())
+        .offlinePartitionCount(topicsMetrics.getOfflinePartitionCount())
+        .zooKeeperStatus(ClusterUtil.convertToIntServerStatus(zookeeperStatus))
+        .version(version)
+        .build();
+
+    return currentCluster.toBuilder()
+        .version(version)
+        .status(ServerStatusDTO.ONLINE)
+        .zookeeperStatus(zookeeperStatus)
+        .lastZookeeperException(zookeeperException)
+        .lastKafkaException(null)
+        .metrics(clusterMetrics)
+        .topics(topics)
+        .brokers(brokersIds)
+        .build();
+  }
+
+  private InternalClusterMetrics collectTopicsMetrics(Map<String, InternalTopic> topics) {
+
+    int underReplicatedPartitions = 0;
+    int inSyncReplicasCount = 0;
+    int outOfSyncReplicasCount = 0;
+    int onlinePartitionCount = 0;
+    int offlinePartitionCount = 0;
+
+    for (InternalTopic topic : topics.values()) {
+      underReplicatedPartitions += topic.getUnderReplicatedPartitions();
+      inSyncReplicasCount += topic.getInSyncReplicas();
+      outOfSyncReplicasCount += (topic.getReplicas() - topic.getInSyncReplicas());
+      onlinePartitionCount +=
+          topic.getPartitions().values().stream().mapToInt(s -> s.getLeader() == null ? 0 : 1)
+              .sum();
+      offlinePartitionCount +=
+          topic.getPartitions().values().stream().mapToInt(s -> s.getLeader() != null ? 0 : 1)
+              .sum();
+    }
+
+    return InternalClusterMetrics.builder()
+        .underReplicatedPartitionCount(underReplicatedPartitions)
+        .inSyncReplicasCount(inSyncReplicasCount)
+        .outOfSyncReplicasCount(outOfSyncReplicasCount)
+        .onlinePartitionCount(onlinePartitionCount)
+        .offlinePartitionCount(offlinePartitionCount)
+        .topicCount(topics.size())
+        .build();
+  }
+
+  private Mono<InternalClusterMetrics> getClusterMetrics(ReactiveAdminClient client) {
+    return client.describeCluster().map(desc ->
+        InternalClusterMetrics.builder()
+            .brokerCount(desc.getNodes().size())
+            .activeControllers(desc.getController() != null ? 1 : 0)
+            .build()
+    );
+  }
+
+  private InternalTopic mergeWithStats(InternalTopic topic,
+                                       Map<String, LongSummaryStatistics> topics,
+                                       Map<TopicPartition, LongSummaryStatistics> partitions) {
+    final LongSummaryStatistics stats = topics.get(topic.getName());
+
+    return topic.toBuilder()
+        .segmentSize(stats.getSum())
+        .segmentCount(stats.getCount())
+        .partitions(
+            topic.getPartitions().entrySet().stream().map(e ->
+                Tuples.of(e.getKey(), mergeWithStats(topic.getName(), e.getValue(), partitions))
+            ).collect(Collectors.toMap(
+                Tuple2::getT1,
+                Tuple2::getT2
+            ))
+        ).build();
+  }
+
+  private InternalPartition mergeWithStats(String topic, InternalPartition partition,
+                                           Map<TopicPartition, LongSummaryStatistics> partitions) {
+    final LongSummaryStatistics stats =
+        partitions.get(new TopicPartition(topic, partition.getPartition()));
+    return partition.toBuilder()
+        .segmentSize(stats.getSum())
+        .segmentCount(stats.getCount())
+        .build();
+  }
+
+  private Mono<InternalSegmentSizeDto> emptySegmentMetrics(InternalClusterMetrics clusterMetrics,
+                                                            List<InternalTopic> internalTopics) {
+    return Mono.just(
+        InternalSegmentSizeDto.builder()
+        .clusterMetricsWithSegmentSize(
+            clusterMetrics.toBuilder()
+                .segmentSize(0)
+                .segmentCount(0)
+                .internalBrokerDiskUsage(Collections.emptyMap())
+                .build()
+        )
+        .internalTopicWithSegmentSize(
+            internalTopics.stream().collect(
+                Collectors.toMap(
+                    InternalTopic::getName,
+                    i -> i
+                )
+            )
+        ).build()
+    );
+  }
+
+  private Mono<InternalSegmentSizeDto> updateSegmentMetrics(ReactiveAdminClient ac,
+                                                            InternalClusterMetrics clusterMetrics,
+                                                            List<InternalTopic> internalTopics) {
+    return ac.describeCluster().flatMap(
+        clusterDescription ->
+                ac.describeLogDirs().map(log -> {
+                  final List<Tuple3<Integer, TopicPartition, Long>> topicPartitions =
+                      log.entrySet().stream().flatMap(b ->
+                          b.getValue().entrySet().stream().flatMap(topicMap ->
+                              topicMap.getValue().replicaInfos.entrySet().stream()
+                                  .map(e -> Tuples.of(b.getKey(), e.getKey(), e.getValue().size))
+                          )
+                      ).collect(Collectors.toList());
+
+                  final Map<TopicPartition, LongSummaryStatistics> partitionStats =
+                      topicPartitions.stream().collect(
+                          Collectors.groupingBy(
+                              Tuple2::getT2,
+                              Collectors.summarizingLong(Tuple3::getT3)
+                          )
+                      );
+
+                  final Map<String, LongSummaryStatistics> topicStats =
+                      topicPartitions.stream().collect(
+                          Collectors.groupingBy(
+                              t -> t.getT2().topic(),
+                              Collectors.summarizingLong(Tuple3::getT3)
+                          )
+                      );
+
+                  final Map<Integer, LongSummaryStatistics> brokerStats =
+                      topicPartitions.stream().collect(
+                          Collectors.groupingBy(
+                              Tuple2::getT1,
+                              Collectors.summarizingLong(Tuple3::getT3)
+                          )
+                      );
+
+
+                  final LongSummaryStatistics summary =
+                      topicPartitions.stream().collect(Collectors.summarizingLong(Tuple3::getT3));
+
+
+                  final Map<String, InternalTopic> resultTopics = internalTopics.stream().map(e ->
+                      Tuples.of(e.getName(), mergeWithStats(e, topicStats, partitionStats))
+                  ).collect(Collectors.toMap(
+                      Tuple2::getT1,
+                      Tuple2::getT2
+                  ));
+
+                  final Map<Integer, InternalBrokerDiskUsage> resultBrokers =
+                      brokerStats.entrySet().stream().map(e ->
+                          Tuples.of(e.getKey(), InternalBrokerDiskUsage.builder()
+                              .segmentSize(e.getValue().getSum())
+                              .segmentCount(e.getValue().getCount())
+                              .build()
+                          )
+                      ).collect(Collectors.toMap(
+                          Tuple2::getT1,
+                          Tuple2::getT2
+                      ));
+
+                  return InternalSegmentSizeDto.builder()
+                      .clusterMetricsWithSegmentSize(
+                          clusterMetrics.toBuilder()
+                              .segmentSize(summary.getSum())
+                              .segmentCount(summary.getCount())
+                              .internalBrokerDiskUsage(resultBrokers)
+                              .build()
+                      )
+                      .internalTopicWithSegmentSize(resultTopics).build();
+                })
+    );
+  }
+
+  private List<MetricDTO> getJmxMetric(KafkaCluster cluster, Node node) {
+    return Optional.of(cluster)
+        .filter(c -> c.getJmxPort() != null)
+        .filter(c -> c.getJmxPort() > 0)
+        .map(c -> jmxClusterUtil.getJmxMetrics(node.host(), c.getJmxPort(), c.isJmxSsl(),
+                c.getJmxUsername(), c.getJmxPassword()))
+        .orElse(Collections.emptyList());
+  }
+
+  private Mono<InternalClusterMetrics> fillJmxMetrics(InternalClusterMetrics internalClusterMetrics,
+                                                      KafkaCluster cluster,
+                                                      ReactiveAdminClient ac) {
+    return fillBrokerMetrics(internalClusterMetrics, cluster, ac)
+        .map(this::calculateClusterMetrics);
+  }
+
+  private Mono<InternalClusterMetrics> fillBrokerMetrics(
+      InternalClusterMetrics internalClusterMetrics, KafkaCluster cluster, ReactiveAdminClient ac) {
+    return ac.describeCluster()
+        .flatMapIterable(ReactiveAdminClient.ClusterDescription::getNodes)
+        .map(broker ->
+            Map.of(broker.id(), InternalBrokerMetrics.builder()
+                .metrics(getJmxMetric(cluster, broker)).build())
+        )
+        .collectList()
+        .map(s -> internalClusterMetrics.toBuilder()
+            .internalBrokerMetrics(ClusterUtil.toSingleMap(s.stream())).build());
+  }
+
+  private InternalClusterMetrics calculateClusterMetrics(
+      InternalClusterMetrics internalClusterMetrics) {
+    final List<MetricDTO> metrics = internalClusterMetrics.getInternalBrokerMetrics().values()
+        .stream()
+        .flatMap(b -> b.getMetrics().stream())
+        .collect(
+            Collectors.groupingBy(
+                MetricDTO::getCanonicalName,
+                Collectors.reducing(jmxClusterUtil::reduceJmxMetrics)
+            )
+        ).values().stream()
+        .filter(Optional::isPresent)
+        .map(Optional::get)
+        .collect(Collectors.toList());
+    final InternalClusterMetrics.InternalClusterMetricsBuilder metricsBuilder =
+        internalClusterMetrics.toBuilder().metrics(metrics);
+    metricsBuilder.bytesInPerSec(findTopicMetrics(
+        metrics, JmxMetricsName.BytesInPerSec, JmxMetricsValueName.FiveMinuteRate
+    ));
+    metricsBuilder.bytesOutPerSec(findTopicMetrics(
+        metrics, JmxMetricsName.BytesOutPerSec, JmxMetricsValueName.FiveMinuteRate
+    ));
+    return metricsBuilder.build();
+  }
+
+  private Map<String, BigDecimal> findTopicMetrics(List<MetricDTO> metrics,
+                                                   JmxMetricsName metricsName,
+                                                   JmxMetricsValueName valueName) {
+    return metrics.stream().filter(m -> metricsName.name().equals(m.getName()))
+        .filter(m -> m.getParams().containsKey("topic"))
+        .filter(m -> m.getValue().containsKey(valueName.name()))
+        .map(m -> Tuples.of(
+            m.getParams().get("topic"),
+            m.getValue().get(valueName.name())
+        )).collect(Collectors.groupingBy(
+            Tuple2::getT1,
+            Collectors.reducing(BigDecimal.ZERO, Tuple2::getT2, BigDecimal::add)
+        ));
+  }
+}

kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/MetricsUpdateService.java

@@ -1,20 +0,0 @@
-package com.provectus.kafka.ui.service;
-
-import com.provectus.kafka.ui.model.KafkaCluster;
-import lombok.RequiredArgsConstructor;
-import lombok.extern.log4j.Log4j2;
-import org.springframework.stereotype.Service;
-import reactor.core.publisher.Mono;
-
-@Service
-@RequiredArgsConstructor
-@Log4j2
-public class MetricsUpdateService {
-
-  private final KafkaService kafkaService;
-
-  public Mono<KafkaCluster> updateMetrics(KafkaCluster kafkaCluster) {
-    log.debug("Start getting metrics for kafkaCluster: {}", kafkaCluster.getName());
-    return kafkaService.getUpdatedCluster(kafkaCluster);
-  }
-}

kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/ReactiveAdminClient.java

@@ -4,6 +4,8 @@ import static com.google.common.util.concurrent.Uninterruptibles.getUninterrupti
 import static java.util.stream.Collectors.toList;
 import static java.util.stream.Collectors.toMap;
 
+import com.provectus.kafka.ui.exception.IllegalEntityStateException;
+import com.provectus.kafka.ui.exception.NotFoundException;
 import com.provectus.kafka.ui.util.MapUtil;
 import com.provectus.kafka.ui.util.NumberUtil;
 import java.io.Closeable;
@@ -40,6 +42,8 @@ import org.apache.kafka.common.TopicPartition;
 import org.apache.kafka.common.TopicPartitionReplica;
 import org.apache.kafka.common.acl.AclOperation;
 import org.apache.kafka.common.config.ConfigResource;
+import org.apache.kafka.common.errors.GroupIdNotFoundException;
+import org.apache.kafka.common.errors.GroupNotEmptyException;
 import org.apache.kafka.common.requests.DescribeLogDirsResponse;
 import reactor.core.publisher.Mono;
 
@@ -186,7 +190,11 @@ public class ReactiveAdminClient implements Closeable {
   }
 
   public Mono<Void> deleteConsumerGroups(Collection<String> groupIds) {
-    return toMono(client.deleteConsumerGroups(groupIds).all());
+    return toMono(client.deleteConsumerGroups(groupIds).all())
+        .onErrorResume(GroupIdNotFoundException.class,
+            th -> Mono.error(new NotFoundException("The group id does not exist")))
+        .onErrorResume(GroupNotEmptyException.class,
+            th -> Mono.error(new IllegalEntityStateException("The group is not empty")));
   }
 
   public Mono<Void> createTopic(String name,

kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/TopicsService.java

@@ -0,0 +1,443 @@
+package com.provectus.kafka.ui.service;
+
+import com.provectus.kafka.ui.exception.TopicMetadataException;
+import com.provectus.kafka.ui.exception.TopicNotFoundException;
+import com.provectus.kafka.ui.exception.ValidationException;
+import com.provectus.kafka.ui.mapper.ClusterMapper;
+import com.provectus.kafka.ui.model.CleanupPolicy;
+import com.provectus.kafka.ui.model.Feature;
+import com.provectus.kafka.ui.model.InternalPartition;
+import com.provectus.kafka.ui.model.InternalReplica;
+import com.provectus.kafka.ui.model.InternalTopic;
+import com.provectus.kafka.ui.model.InternalTopicConfig;
+import com.provectus.kafka.ui.model.KafkaCluster;
+import com.provectus.kafka.ui.model.PartitionsIncreaseDTO;
+import com.provectus.kafka.ui.model.PartitionsIncreaseResponseDTO;
+import com.provectus.kafka.ui.model.ReplicationFactorChangeDTO;
+import com.provectus.kafka.ui.model.ReplicationFactorChangeResponseDTO;
+import com.provectus.kafka.ui.model.TopicColumnsToSortDTO;
+import com.provectus.kafka.ui.model.TopicConfigDTO;
+import com.provectus.kafka.ui.model.TopicCreationDTO;
+import com.provectus.kafka.ui.model.TopicDTO;
+import com.provectus.kafka.ui.model.TopicDetailsDTO;
+import com.provectus.kafka.ui.model.TopicMessageSchemaDTO;
+import com.provectus.kafka.ui.model.TopicUpdateDTO;
+import com.provectus.kafka.ui.model.TopicsResponseDTO;
+import com.provectus.kafka.ui.serde.DeserializationService;
+import com.provectus.kafka.ui.util.ClusterUtil;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.Comparator;
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+import java.util.function.Predicate;
+import java.util.stream.Collectors;
+import lombok.RequiredArgsConstructor;
+import lombok.SneakyThrows;
+import org.apache.commons.lang3.StringUtils;
+import org.apache.kafka.clients.admin.NewPartitionReassignment;
+import org.apache.kafka.clients.admin.NewPartitions;
+import org.apache.kafka.common.TopicPartition;
+import org.springframework.stereotype.Service;
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
+
+@Service
+@RequiredArgsConstructor
+public class TopicsService {
+
+  private static final Integer DEFAULT_PAGE_SIZE = 25;
+
+  private final AdminClientService adminClientService;
+  private final ConsumerGroupService consumerGroupService;
+  private final ClustersStorage clustersStorage;
+  private final ClusterMapper clusterMapper;
+  private final DeserializationService deserializationService;
+
+  public TopicsResponseDTO getTopics(KafkaCluster cluster,
+                                     Optional<Integer> page,
+                                     Optional<Integer> nullablePerPage,
+                                     Optional<Boolean> showInternal,
+                                     Optional<String> search,
+                                     Optional<TopicColumnsToSortDTO> sortBy) {
+    Predicate<Integer> positiveInt = i -> i > 0;
+    int perPage = nullablePerPage.filter(positiveInt).orElse(DEFAULT_PAGE_SIZE);
+    var topicsToSkip = (page.filter(positiveInt).orElse(1) - 1) * perPage;
+    List<InternalTopic> topics = cluster.getTopics().values().stream()
+        .filter(topic -> !topic.isInternal()
+            || showInternal
+            .map(i -> topic.isInternal() == i)
+            .orElse(true))
+        .filter(topic ->
+            search
+                .map(s -> StringUtils.containsIgnoreCase(topic.getName(), s))
+                .orElse(true))
+        .sorted(getComparatorForTopic(sortBy))
+        .collect(Collectors.toList());
+    var totalPages = (topics.size() / perPage)
+        + (topics.size() % perPage == 0 ? 0 : 1);
+    return new TopicsResponseDTO()
+        .pageCount(totalPages)
+        .topics(
+            topics.stream()
+                .skip(topicsToSkip)
+                .limit(perPage)
+                .map(t ->
+                    clusterMapper.toTopic(
+                        t.toBuilder().partitions(getTopicPartitions(cluster, t)).build()
+                    )
+                )
+                .collect(Collectors.toList())
+        );
+  }
+
+  private Comparator<InternalTopic> getComparatorForTopic(Optional<TopicColumnsToSortDTO> sortBy) {
+    var defaultComparator = Comparator.comparing(InternalTopic::getName);
+    if (sortBy.isEmpty()) {
+      return defaultComparator;
+    }
+    switch (sortBy.get()) {
+      case TOTAL_PARTITIONS:
+        return Comparator.comparing(InternalTopic::getPartitionCount);
+      case OUT_OF_SYNC_REPLICAS:
+        return Comparator.comparing(t -> t.getReplicas() - t.getInSyncReplicas());
+      case REPLICATION_FACTOR:
+        return Comparator.comparing(InternalTopic::getReplicationFactor);
+      case NAME:
+      default:
+        return defaultComparator;
+    }
+  }
+
+  public Optional<TopicDetailsDTO> getTopicDetails(KafkaCluster cluster, String topicName) {
+    return Optional.ofNullable(cluster.getTopics()).map(l -> l.get(topicName)).map(
+        t -> t.toBuilder().partitions(getTopicPartitions(cluster, t)
+        ).build()
+    ).map(t -> clusterMapper.toTopicDetails(t, cluster.getMetrics()));
+  }
+
+  @SneakyThrows
+  public Mono<List<InternalTopic>> getTopicsData(ReactiveAdminClient client) {
+    return client.listTopics(true)
+        .flatMap(topics -> getTopicsData(client, topics).collectList());
+  }
+
+  private Flux<InternalTopic> getTopicsData(ReactiveAdminClient client, Collection<String> topics) {
+    final Mono<Map<String, List<InternalTopicConfig>>> configsMono =
+        loadTopicsConfig(client, topics);
+
+    return client.describeTopics(topics)
+        .map(m -> m.values().stream()
+            .map(ClusterUtil::mapToInternalTopic).collect(Collectors.toList()))
+        .flatMap(internalTopics -> configsMono
+            .map(configs -> mergeWithConfigs(internalTopics, configs).values()))
+        .flatMapMany(Flux::fromIterable);
+  }
+
+  public Optional<List<TopicConfigDTO>> getTopicConfigs(KafkaCluster cluster, String topicName) {
+    return Optional.of(cluster)
+        .map(KafkaCluster::getTopics)
+        .map(t -> t.get(topicName))
+        .map(t -> t.getTopicConfigs().stream().map(clusterMapper::toTopicConfig)
+            .collect(Collectors.toList()));
+  }
+
+
+  @SneakyThrows
+  private Mono<InternalTopic> createTopic(ReactiveAdminClient adminClient,
+                                         Mono<TopicCreationDTO> topicCreation) {
+    return topicCreation.flatMap(topicData ->
+            adminClient.createTopic(
+                topicData.getName(),
+                topicData.getPartitions(),
+                topicData.getReplicationFactor().shortValue(),
+                topicData.getConfigs()
+            ).thenReturn(topicData)
+        )
+        .onErrorResume(t -> Mono.error(new TopicMetadataException(t.getMessage())))
+        .flatMap(topicData -> getUpdatedTopic(adminClient, topicData.getName()))
+        .switchIfEmpty(Mono.error(new RuntimeException("Can't find created topic")));
+  }
+
+  public Mono<TopicDTO> createTopic(
+      KafkaCluster cluster, Mono<TopicCreationDTO> topicCreation) {
+    return adminClientService.get(cluster).flatMap(ac -> createTopic(ac, topicCreation))
+        .doOnNext(t -> clustersStorage.onTopicUpdated(cluster, t))
+        .map(clusterMapper::toTopic);
+  }
+
+  private Map<String, InternalTopic> mergeWithConfigs(
+      List<InternalTopic> topics, Map<String, List<InternalTopicConfig>> configs) {
+    return topics.stream()
+        .map(t -> t.toBuilder().topicConfigs(configs.get(t.getName())).build())
+        .map(t -> t.toBuilder().cleanUpPolicy(
+            CleanupPolicy.fromString(t.getTopicConfigs().stream()
+                .filter(config -> config.getName().equals("cleanup.policy"))
+                .findFirst()
+                .orElseGet(() -> InternalTopicConfig.builder().value("unknown").build())
+                .getValue())).build())
+        .collect(Collectors.toMap(
+            InternalTopic::getName,
+            e -> e
+        ));
+  }
+
+  public Mono<InternalTopic> getUpdatedTopic(ReactiveAdminClient ac, String topicName) {
+    return getTopicsData(ac, List.of(topicName)).next();
+  }
+
+  public Mono<InternalTopic> updateTopic(KafkaCluster cluster,
+                                         String topicName,
+                                         TopicUpdateDTO topicUpdate) {
+    return adminClientService.get(cluster)
+        .flatMap(ac ->
+            ac.updateTopicConfig(topicName,
+                topicUpdate.getConfigs()).then(getUpdatedTopic(ac, topicName)));
+  }
+
+  public Mono<TopicDTO> updateTopic(KafkaCluster cl, String topicName,
+                                    Mono<TopicUpdateDTO> topicUpdate) {
+    return topicUpdate
+        .flatMap(t -> updateTopic(cl, topicName, t))
+        .doOnNext(t -> clustersStorage.onTopicUpdated(cl, t))
+        .map(clusterMapper::toTopic);
+  }
+
+  @SneakyThrows
+  private Mono<Map<String, List<InternalTopicConfig>>> loadTopicsConfig(
+      ReactiveAdminClient client, Collection<String> topicNames) {
+    return client.getTopicsConfig(topicNames)
+        .map(configs ->
+            configs.entrySet().stream().collect(Collectors.toMap(
+                Map.Entry::getKey,
+                c -> c.getValue().stream()
+                    .map(ClusterUtil::mapToInternalTopicConfig)
+                    .collect(Collectors.toList()))));
+  }
+
+  private Mono<InternalTopic> changeReplicationFactor(
+      ReactiveAdminClient adminClient,
+      String topicName,
+      Map<TopicPartition, Optional<NewPartitionReassignment>> reassignments
+  ) {
+    return adminClient.alterPartitionReassignments(reassignments)
+        .then(getUpdatedTopic(adminClient, topicName));
+  }
+
+  /**
+   * Change topic replication factor, works on brokers versions 5.4.x and higher
+   */
+  public Mono<ReplicationFactorChangeResponseDTO> changeReplicationFactor(
+      KafkaCluster cluster,
+      String topicName,
+      ReplicationFactorChangeDTO replicationFactorChange) {
+    return adminClientService.get(cluster)
+        .flatMap(ac -> {
+          Integer actual = cluster.getTopics().get(topicName).getReplicationFactor();
+          Integer requested = replicationFactorChange.getTotalReplicationFactor();
+          Integer brokersCount = cluster.getMetrics().getBrokerCount();
+
+          if (requested.equals(actual)) {
+            return Mono.error(
+                new ValidationException(
+                    String.format("Topic already has replicationFactor %s.", actual)));
+          }
+          if (requested > brokersCount) {
+            return Mono.error(
+                new ValidationException(
+                    String.format("Requested replication factor %s more than brokers count %s.",
+                        requested, brokersCount)));
+          }
+          return changeReplicationFactor(ac, topicName,
+              getPartitionsReassignments(cluster, topicName,
+                  replicationFactorChange));
+        })
+        .doOnNext(topic -> clustersStorage.onTopicUpdated(cluster, topic))
+        .map(t -> new ReplicationFactorChangeResponseDTO()
+            .topicName(t.getName())
+            .totalReplicationFactor(t.getReplicationFactor()));
+  }
+
+  private Map<TopicPartition, Optional<NewPartitionReassignment>> getPartitionsReassignments(
+      KafkaCluster cluster,
+      String topicName,
+      ReplicationFactorChangeDTO replicationFactorChange) {
+    // Current assignment map (Partition number -> List of brokers)
+    Map<Integer, List<Integer>> currentAssignment = getCurrentAssignment(cluster, topicName);
+    // Brokers map (Broker id -> count)
+    Map<Integer, Integer> brokersUsage = getBrokersMap(cluster, currentAssignment);
+    int currentReplicationFactor = cluster.getTopics().get(topicName).getReplicationFactor();
+
+    // If we should to increase Replication factor
+    if (replicationFactorChange.getTotalReplicationFactor() > currentReplicationFactor) {
+      // For each partition
+      for (var assignmentList : currentAssignment.values()) {
+        // Get brokers list sorted by usage
+        var brokers = brokersUsage.entrySet().stream()
+            .sorted(Map.Entry.comparingByValue())
+            .map(Map.Entry::getKey)
+            .collect(Collectors.toList());
+
+        // Iterate brokers and try to add them in assignment
+        // while (partition replicas count != requested replication factor)
+        for (Integer broker : brokers) {
+          if (!assignmentList.contains(broker)) {
+            assignmentList.add(broker);
+            brokersUsage.merge(broker, 1, Integer::sum);
+          }
+          if (assignmentList.size() == replicationFactorChange.getTotalReplicationFactor()) {
+            break;
+          }
+        }
+        if (assignmentList.size() != replicationFactorChange.getTotalReplicationFactor()) {
+          throw new ValidationException("Something went wrong during adding replicas");
+        }
+      }
+
+      // If we should to decrease Replication factor
+    } else if (replicationFactorChange.getTotalReplicationFactor() < currentReplicationFactor) {
+      for (Map.Entry<Integer, List<Integer>> assignmentEntry : currentAssignment.entrySet()) {
+        var partition = assignmentEntry.getKey();
+        var brokers = assignmentEntry.getValue();
+
+        // Get brokers list sorted by usage in reverse order
+        var brokersUsageList = brokersUsage.entrySet().stream()
+            .sorted(Map.Entry.comparingByValue(Comparator.reverseOrder()))
+            .map(Map.Entry::getKey)
+            .collect(Collectors.toList());
+
+        // Iterate brokers and try to remove them from assignment
+        // while (partition replicas count != requested replication factor)
+        for (Integer broker : brokersUsageList) {
+          // Check is the broker the leader of partition
+          if (!cluster.getTopics().get(topicName).getPartitions().get(partition).getLeader()
+              .equals(broker)) {
+            brokers.remove(broker);
+            brokersUsage.merge(broker, -1, Integer::sum);
+          }
+          if (brokers.size() == replicationFactorChange.getTotalReplicationFactor()) {
+            break;
+          }
+        }
+        if (brokers.size() != replicationFactorChange.getTotalReplicationFactor()) {
+          throw new ValidationException("Something went wrong during removing replicas");
+        }
+      }
+    } else {
+      throw new ValidationException("Replication factor already equals requested");
+    }
+
+    // Return result map
+    return currentAssignment.entrySet().stream().collect(Collectors.toMap(
+        e -> new TopicPartition(topicName, e.getKey()),
+        e -> Optional.of(new NewPartitionReassignment(e.getValue()))
+    ));
+  }
+
+  private Map<Integer, List<Integer>> getCurrentAssignment(KafkaCluster cluster, String topicName) {
+    return cluster.getTopics().get(topicName).getPartitions().values().stream()
+        .collect(Collectors.toMap(
+            InternalPartition::getPartition,
+            p -> p.getReplicas().stream()
+                .map(InternalReplica::getBroker)
+                .collect(Collectors.toList())
+        ));
+  }
+
+  private Map<Integer, Integer> getBrokersMap(KafkaCluster cluster,
+                                              Map<Integer, List<Integer>> currentAssignment) {
+    Map<Integer, Integer> result = cluster.getBrokers().stream()
+        .collect(Collectors.toMap(
+            c -> c,
+            c -> 0
+        ));
+    currentAssignment.values().forEach(brokers -> brokers
+        .forEach(broker -> result.put(broker, result.get(broker) + 1)));
+
+    return result;
+  }
+
+  public Mono<PartitionsIncreaseResponseDTO> increaseTopicPartitions(
+      KafkaCluster cluster,
+      String topicName,
+      PartitionsIncreaseDTO partitionsIncrease) {
+    return adminClientService.get(cluster)
+        .flatMap(ac -> {
+          Integer actualCount = cluster.getTopics().get(topicName).getPartitionCount();
+          Integer requestedCount = partitionsIncrease.getTotalPartitionsCount();
+
+          if (requestedCount < actualCount) {
+            return Mono.error(
+                new ValidationException(String.format(
+                    "Topic currently has %s partitions, which is higher than the requested %s.",
+                    actualCount, requestedCount)));
+          }
+          if (requestedCount.equals(actualCount)) {
+            return Mono.error(
+                new ValidationException(
+                    String.format("Topic already has %s partitions.", actualCount)));
+          }
+
+          Map<String, NewPartitions> newPartitionsMap = Collections.singletonMap(
+              topicName,
+              NewPartitions.increaseTo(partitionsIncrease.getTotalPartitionsCount())
+          );
+          return ac.createPartitions(newPartitionsMap)
+              .then(getUpdatedTopic(ac, topicName));
+        })
+        .doOnNext(t -> clustersStorage.onTopicUpdated(cluster, t))
+        .map(t -> new PartitionsIncreaseResponseDTO()
+            .topicName(t.getName())
+            .totalPartitionsCount(t.getPartitionCount()));
+  }
+
+  private Map<Integer, InternalPartition> getTopicPartitions(KafkaCluster c, InternalTopic topic) {
+    var tps = topic.getPartitions().values().stream()
+        .map(t -> new TopicPartition(topic.getName(), t.getPartition()))
+        .collect(Collectors.toList());
+    Map<Integer, InternalPartition> partitions =
+        topic.getPartitions().values().stream().collect(Collectors.toMap(
+            InternalPartition::getPartition,
+            tp -> tp
+        ));
+
+    try (var consumer = consumerGroupService.createConsumer(c)) {
+      final Map<TopicPartition, Long> earliest = consumer.beginningOffsets(tps);
+      final Map<TopicPartition, Long> latest = consumer.endOffsets(tps);
+
+      return tps.stream()
+          .map(tp -> partitions.get(tp.partition()).toBuilder()
+              .offsetMin(Optional.ofNullable(earliest.get(tp)).orElse(0L))
+              .offsetMax(Optional.ofNullable(latest.get(tp)).orElse(0L))
+              .build()
+          ).collect(Collectors.toMap(
+              InternalPartition::getPartition,
+              tp -> tp
+          ));
+    } catch (Exception e) {
+      return Collections.emptyMap();
+    }
+  }
+
+  public Mono<Void> deleteTopic(KafkaCluster cluster, String topicName) {
+    var topicDetails = getTopicDetails(cluster, topicName)
+        .orElseThrow(TopicNotFoundException::new);
+    if (cluster.getFeatures().contains(Feature.TOPIC_DELETION)) {
+      return adminClientService.get(cluster).flatMap(c -> c.deleteTopic(topicName))
+          .doOnSuccess(t -> clustersStorage.onTopicDeleted(cluster, topicName));
+    } else {
+      return Mono.error(new ValidationException("Topic deletion restricted"));
+    }
+  }
+
+  public TopicMessageSchemaDTO getTopicSchema(KafkaCluster cluster, String topicName) {
+    if (!cluster.getTopics().containsKey(topicName)) {
+      throw new TopicNotFoundException();
+    }
+    return deserializationService
+        .getRecordDeserializerForCluster(cluster)
+        .getTopicSchema(topicName);
+  }
+
+}

kafka-ui-api/src/test/java/com/provectus/kafka/ui/service/ClusterServiceTest.java

@@ -1,303 +0,0 @@
-package com.provectus.kafka.ui.service;
-
-import static org.assertj.core.api.Assertions.assertThat;
-import static org.mockito.ArgumentMatchers.any;
-import static org.mockito.Mockito.when;
-
-import com.provectus.kafka.ui.mapper.ClusterMapper;
-import com.provectus.kafka.ui.model.InternalTopic;
-import com.provectus.kafka.ui.model.InternalTopicConfig;
-import com.provectus.kafka.ui.model.KafkaCluster;
-import com.provectus.kafka.ui.model.TopicColumnsToSortDTO;
-import com.provectus.kafka.ui.model.TopicDTO;
-import java.util.List;
-import java.util.Map;
-import java.util.Objects;
-import java.util.Optional;
-import java.util.UUID;
-import java.util.function.Function;
-import java.util.stream.Collectors;
-import java.util.stream.IntStream;
-import org.apache.kafka.clients.admin.ConfigEntry;
-import org.junit.jupiter.api.Test;
-import org.junit.jupiter.api.extension.ExtendWith;
-import org.mapstruct.factory.Mappers;
-import org.mockito.InjectMocks;
-import org.mockito.Mock;
-import org.mockito.Spy;
-import org.mockito.junit.jupiter.MockitoExtension;
-
-@ExtendWith(MockitoExtension.class)
-class ClusterServiceTest {
-  @Spy
-  private final ClusterMapper clusterMapper = Mappers.getMapper(ClusterMapper.class);
-  @InjectMocks
-  private ClusterService clusterService;
-  @Mock
-  private ClustersStorage clustersStorage;
-  @Mock
-  private KafkaService kafkaService;
-
-  @Test
-  public void shouldListFirst25Topics() {
-    var topicName = UUID.randomUUID().toString();
-
-    final KafkaCluster cluster = KafkaCluster.builder()
-        .topics(
-            IntStream.rangeClosed(1, 100).boxed()
-                .map(Objects::toString)
-                .collect(Collectors.toMap(Function.identity(), e -> InternalTopic.builder()
-                    .partitions(Map.of())
-                    .name(e)
-                    .build()))
-        )
-        .build();
-
-    when(clustersStorage.getClusterByName(topicName))
-        .thenReturn(Optional.of(cluster));
-
-    when(
-        kafkaService.getTopicPartitions(any(), any())
-    ).thenReturn(
-        Map.of()
-    );
-
-    var topics = clusterService.getTopics(topicName,
-        Optional.empty(), Optional.empty(), Optional.empty(),
-        Optional.empty(), Optional.empty());
-    assertThat(topics.getPageCount()).isEqualTo(4);
-    assertThat(topics.getTopics()).hasSize(25);
-    assertThat(topics.getTopics()).map(TopicDTO::getName).isSorted();
-  }
-
-  @Test
-  public void shouldCalculateCorrectPageCountForNonDivisiblePageSize() {
-    var topicName = UUID.randomUUID().toString();
-
-    when(clustersStorage.getClusterByName(topicName))
-        .thenReturn(Optional.of(KafkaCluster.builder()
-            .topics(
-                IntStream.rangeClosed(1, 100).boxed()
-                    .map(Objects::toString)
-                    .collect(Collectors.toMap(Function.identity(), e -> InternalTopic.builder()
-                        .partitions(Map.of())
-                        .name(e)
-                        .build()))
-            )
-            .build()));
-
-    when(
-        kafkaService.getTopicPartitions(any(), any())
-    ).thenReturn(
-        Map.of()
-    );
-
-
-    var topics = clusterService.getTopics(topicName, Optional.of(4), Optional.of(33),
-        Optional.empty(), Optional.empty(), Optional.empty());
-    assertThat(topics.getPageCount()).isEqualTo(4);
-    assertThat(topics.getTopics()).hasSize(1)
-        .first().extracting(TopicDTO::getName).isEqualTo("99");
-  }
-
-  @Test
-  public void shouldCorrectlyHandleNonPositivePageNumberAndPageSize() {
-    var topicName = UUID.randomUUID().toString();
-
-    when(clustersStorage.getClusterByName(topicName))
-        .thenReturn(Optional.of(KafkaCluster.builder()
-            .topics(
-                IntStream.rangeClosed(1, 100).boxed()
-                    .map(Objects::toString)
-                    .collect(Collectors.toMap(Function.identity(), e -> InternalTopic.builder()
-                        .partitions(Map.of())
-                        .name(e)
-                        .build()))
-            )
-            .build()));
-
-    when(
-        kafkaService.getTopicPartitions(any(), any())
-    ).thenReturn(
-        Map.of()
-    );
-
-
-    var topics = clusterService.getTopics(topicName, Optional.of(0), Optional.of(-1),
-        Optional.empty(), Optional.empty(), Optional.empty());
-    assertThat(topics.getPageCount()).isEqualTo(4);
-    assertThat(topics.getTopics()).hasSize(25);
-    assertThat(topics.getTopics()).map(TopicDTO::getName).isSorted();
-  }
-
-  @Test
-  public void shouldListBotInternalAndNonInternalTopics() {
-    var topicName = UUID.randomUUID().toString();
-
-    when(clustersStorage.getClusterByName(topicName))
-        .thenReturn(Optional.of(KafkaCluster.builder()
-            .topics(
-                IntStream.rangeClosed(1, 100).boxed()
-                    .map(Objects::toString)
-                    .collect(Collectors.toMap(Function.identity(), e -> InternalTopic.builder()
-                        .partitions(Map.of())
-                        .name(e)
-                        .internal(Integer.parseInt(e) % 10 == 0)
-                        .build()))
-            )
-            .build()));
-
-    when(
-        kafkaService.getTopicPartitions(any(), any())
-    ).thenReturn(
-        Map.of()
-    );
-
-
-    var topics = clusterService.getTopics(topicName,
-        Optional.empty(), Optional.empty(), Optional.of(true),
-        Optional.empty(), Optional.empty());
-    assertThat(topics.getPageCount()).isEqualTo(4);
-    assertThat(topics.getTopics()).hasSize(25);
-    assertThat(topics.getTopics()).map(TopicDTO::getName).isSorted();
-  }
-
-
-  @Test
-  public void shouldListOnlyNonInternalTopics() {
-    var topicName = UUID.randomUUID().toString();
-
-    when(clustersStorage.getClusterByName(topicName))
-        .thenReturn(Optional.of(KafkaCluster.builder()
-            .topics(
-                IntStream.rangeClosed(1, 100).boxed()
-                    .map(Objects::toString)
-                    .collect(Collectors.toMap(Function.identity(), e -> InternalTopic.builder()
-                        .partitions(Map.of())
-                        .name(e)
-                        .internal(Integer.parseInt(e) % 10 == 0)
-                        .build()))
-            )
-            .build()));
-
-    when(
-        kafkaService.getTopicPartitions(any(), any())
-    ).thenReturn(
-        Map.of()
-    );
-
-
-    var topics = clusterService.getTopics(topicName,
-        Optional.empty(), Optional.empty(), Optional.of(true),
-        Optional.empty(), Optional.empty());
-    assertThat(topics.getPageCount()).isEqualTo(4);
-    assertThat(topics.getTopics()).hasSize(25);
-    assertThat(topics.getTopics()).map(TopicDTO::getName).isSorted();
-  }
-
-
-  @Test
-  public void shouldListOnlyTopicsContainingOne() {
-    var topicName = UUID.randomUUID().toString();
-
-    when(clustersStorage.getClusterByName(topicName))
-        .thenReturn(Optional.of(KafkaCluster.builder()
-            .topics(
-                IntStream.rangeClosed(1, 100).boxed()
-                    .map(Objects::toString)
-                    .collect(Collectors.toMap(Function.identity(), e -> InternalTopic.builder()
-                        .partitions(Map.of())
-                        .name(e)
-                        .build()))
-            )
-            .build()));
-
-    when(
-        kafkaService.getTopicPartitions(any(), any())
-    ).thenReturn(
-        Map.of()
-    );
-
-
-    var topics = clusterService.getTopics(topicName,
-        Optional.empty(), Optional.empty(), Optional.empty(),
-        Optional.of("1"), Optional.empty());
-    assertThat(topics.getPageCount()).isEqualTo(1);
-    assertThat(topics.getTopics()).hasSize(20);
-    assertThat(topics.getTopics()).map(TopicDTO::getName).isSorted();
-  }
-
-  @Test
-  public void shouldListTopicsOrderedByPartitionsCount() {
-    var topicName = UUID.randomUUID().toString();
-
-    when(clustersStorage.getClusterByName(topicName))
-        .thenReturn(Optional.of(KafkaCluster.builder()
-            .topics(
-                IntStream.rangeClosed(1, 100).boxed()
-                    .map(Objects::toString)
-                    .collect(Collectors.toMap(Function.identity(), e -> InternalTopic.builder()
-                        .partitions(Map.of())
-                        .name(e)
-                        .partitionCount(100 - Integer.parseInt(e))
-                        .build()))
-            )
-            .build()));
-
-    when(
-        kafkaService.getTopicPartitions(any(), any())
-    ).thenReturn(
-        Map.of()
-    );
-
-
-    var topics = clusterService.getTopics(topicName,
-        Optional.empty(), Optional.empty(), Optional.empty(),
-        Optional.empty(), Optional.of(TopicColumnsToSortDTO.TOTAL_PARTITIONS));
-    assertThat(topics.getPageCount()).isEqualTo(4);
-    assertThat(topics.getTopics()).hasSize(25);
-    assertThat(topics.getTopics()).map(TopicDTO::getPartitionCount).isSorted();
-  }
-
-  @Test
-  public void shouldRetrieveTopicConfigs() {
-    var topicName = UUID.randomUUID().toString();
-
-    when(clustersStorage.getClusterByName(topicName))
-        .thenReturn(Optional.of(KafkaCluster.builder()
-            .topics(
-                IntStream.rangeClosed(1, 100).boxed()
-                    .map(Objects::toString)
-                    .collect(Collectors.toMap(Function.identity(), e -> InternalTopic.builder()
-                        .name(e)
-                        .topicConfigs(
-                            List.of(InternalTopicConfig.builder()
-                                .name("testName")
-                                .value("testValue")
-                                .defaultValue("testDefaultValue")
-                                .source(ConfigEntry.ConfigSource.DEFAULT_CONFIG)
-                                .isReadOnly(true)
-                                .isSensitive(true)
-                                .synonyms(List.of())
-                                .build()
-                            )
-                        )
-                        .build()))
-            )
-            .build()));
-
-    var configs = clusterService.getTopicConfigs(topicName, "1");
-    var topicConfig = configs.isPresent() ? configs.get().get(0) : null;
-
-    assertThat(configs.isPresent()).isTrue();
-    assertThat(topicConfig.getName()).isEqualTo("testName");
-    assertThat(topicConfig.getValue()).isEqualTo("testValue");
-    assertThat(topicConfig.getDefaultValue()).isEqualTo("testDefaultValue");
-    assertThat(topicConfig.getSource().getValue())
-            .isEqualTo(ConfigEntry.ConfigSource.DEFAULT_CONFIG.name());
-    assertThat(topicConfig.getSynonyms()).isNotNull();
-    assertThat(topicConfig.getIsReadOnly()).isTrue();
-    assertThat(topicConfig.getIsSensitive()).isTrue();
-  }
-
-}

kafka-ui-api/src/test/java/com/provectus/kafka/ui/service/KsqlServiceTest.java

@@ -7,7 +7,6 @@ import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
 import com.provectus.kafka.ui.client.KsqlClient;
-import com.provectus.kafka.ui.exception.ClusterNotFoundException;
 import com.provectus.kafka.ui.exception.KsqlDbNotFoundException;
 import com.provectus.kafka.ui.exception.UnprocessableEntityException;
 import com.provectus.kafka.ui.model.KafkaCluster;
@@ -17,7 +16,6 @@ import com.provectus.kafka.ui.strategy.ksql.statement.BaseStrategy;
 import com.provectus.kafka.ui.strategy.ksql.statement.DescribeStrategy;
 import com.provectus.kafka.ui.strategy.ksql.statement.ShowStrategy;
 import java.util.List;
-import java.util.Optional;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.ExtendWith;
@@ -45,81 +43,58 @@ class KsqlServiceTest {
     this.alternativeStrategy = new DescribeStrategy();
     this.ksqlService = new KsqlService(
         this.ksqlClient,
-        this.clustersStorage,
         List.of(baseStrategy, alternativeStrategy)
     );
   }
 
-  @Test
-  void shouldThrowClusterNotFoundExceptionOnExecuteKsqlCommand() {
-    String clusterName = "test";
-    KsqlCommandDTO command = (new KsqlCommandDTO()).ksql("show streams;");
-    when(clustersStorage.getClusterByName(clusterName)).thenReturn(Optional.ofNullable(null));
-
-    StepVerifier.create(ksqlService.executeKsqlCommand(clusterName, Mono.just(command)))
-        .verifyError(ClusterNotFoundException.class);
-  }
-
   @Test
   void shouldThrowKsqlDbNotFoundExceptionOnExecuteKsqlCommand() {
-    String clusterName = "test";
     KsqlCommandDTO command = (new KsqlCommandDTO()).ksql("show streams;");
     KafkaCluster kafkaCluster = Mockito.mock(KafkaCluster.class);
-    when(clustersStorage.getClusterByName(clusterName))
-        .thenReturn(Optional.ofNullable(kafkaCluster));
     when(kafkaCluster.getKsqldbServer()).thenReturn(null);
 
-    StepVerifier.create(ksqlService.executeKsqlCommand(clusterName, Mono.just(command)))
+    StepVerifier.create(ksqlService.executeKsqlCommand(kafkaCluster, Mono.just(command)))
         .verifyError(KsqlDbNotFoundException.class);
   }
 
   @Test
   void shouldThrowUnprocessableEntityExceptionOnExecuteKsqlCommand() {
-    String clusterName = "test";
     KsqlCommandDTO command =
         (new KsqlCommandDTO()).ksql("CREATE STREAM users WITH (KAFKA_TOPIC='users');");
     KafkaCluster kafkaCluster = Mockito.mock(KafkaCluster.class);
-    when(clustersStorage.getClusterByName(clusterName))
-        .thenReturn(Optional.ofNullable(kafkaCluster));
     when(kafkaCluster.getKsqldbServer()).thenReturn("localhost:8088");
 
-    StepVerifier.create(ksqlService.executeKsqlCommand(clusterName, Mono.just(command)))
+    StepVerifier.create(ksqlService.executeKsqlCommand(kafkaCluster, Mono.just(command)))
         .verifyError(UnprocessableEntityException.class);
 
-    StepVerifier.create(ksqlService.executeKsqlCommand(clusterName, Mono.just(command)))
+    StepVerifier.create(ksqlService.executeKsqlCommand(kafkaCluster, Mono.just(command)))
         .verifyErrorMessage("Invalid sql");
   }
 
   @Test
   void shouldSetHostToStrategy() {
-    String clusterName = "test";
     String host = "localhost:8088";
     KsqlCommandDTO command = (new KsqlCommandDTO()).ksql("describe streams;");
     KafkaCluster kafkaCluster = Mockito.mock(KafkaCluster.class);
 
-    when(clustersStorage.getClusterByName(clusterName))
-        .thenReturn(Optional.ofNullable(kafkaCluster));
     when(kafkaCluster.getKsqldbServer()).thenReturn(host);
     when(ksqlClient.execute(any())).thenReturn(Mono.just(new KsqlCommandResponseDTO()));
 
-    ksqlService.executeKsqlCommand(clusterName, Mono.just(command)).block();
+    ksqlService.executeKsqlCommand(kafkaCluster, Mono.just(command)).block();
     assertThat(alternativeStrategy.getUri()).isEqualTo(host + "/ksql");
   }
 
   @Test
   void shouldCallClientAndReturnResponse() {
-    String clusterName = "test";
     KsqlCommandDTO command = (new KsqlCommandDTO()).ksql("describe streams;");
     KafkaCluster kafkaCluster = Mockito.mock(KafkaCluster.class);
     KsqlCommandResponseDTO response = new KsqlCommandResponseDTO().message("success");
 
-    when(clustersStorage.getClusterByName(clusterName))
-        .thenReturn(Optional.ofNullable(kafkaCluster));
     when(kafkaCluster.getKsqldbServer()).thenReturn("host");
     when(ksqlClient.execute(any())).thenReturn(Mono.just(response));
 
     KsqlCommandResponseDTO receivedResponse =
-        ksqlService.executeKsqlCommand(clusterName, Mono.just(command)).block();
+        ksqlService.executeKsqlCommand(kafkaCluster, Mono.just(command)).block();
     verify(ksqlClient, times(1)).execute(alternativeStrategy);
     assertThat(receivedResponse).isEqualTo(response);
 

kafka-ui-api/src/test/java/com/provectus/kafka/ui/service/SendAndReadTests.java

@@ -7,6 +7,7 @@ import com.fasterxml.jackson.databind.ObjectMapper;
 import com.provectus.kafka.ui.AbstractBaseTest;
 import com.provectus.kafka.ui.model.ConsumerPosition;
 import com.provectus.kafka.ui.model.CreateTopicMessageDTO;
+import com.provectus.kafka.ui.model.KafkaCluster;
 import com.provectus.kafka.ui.model.MessageFormatDTO;
 import com.provectus.kafka.ui.model.SeekDirectionDTO;
 import com.provectus.kafka.ui.model.SeekTypeDTO;
@@ -24,6 +25,7 @@ import java.util.function.Consumer;
 import lombok.SneakyThrows;
 import org.apache.kafka.clients.admin.NewTopic;
 import org.apache.kafka.common.TopicPartition;
+import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.test.context.ContextConfiguration;
@@ -118,12 +120,22 @@ public class SendAndReadTests extends AbstractBaseTest {
   private static final String JSON_SCHEMA_RECORD
       = "{ \"f1\": 12, \"f2\": \"testJsonSchema1\", \"schema\": \"some txt\" }";
 
+  private KafkaCluster targetCluster;
+
+  @Autowired
+  private MessagesService messagesService;
+
   @Autowired
-  private ClusterService clusterService;
+  private ClustersStorage clustersStorage;
 
   @Autowired
   private ClustersMetricsScheduler clustersMetricsScheduler;
 
+  @BeforeEach
+  void init() {
+    targetCluster = clustersStorage.getClusterByName(LOCAL).get();
+  }
+
   @Test
   void noSchemaStringKeyStringValue() {
     new SendAndReadSpec()
@@ -500,7 +512,8 @@ public class SendAndReadTests extends AbstractBaseTest {
     public void assertSendThrowsException() {
       String topic = createTopicAndCreateSchemas();
       try {
-        assertThatThrownBy(() -> clusterService.sendMessage(LOCAL, topic, msgToSend).block());
+        assertThatThrownBy(() ->
+            messagesService.sendMessage(targetCluster, topic, msgToSend).block());
       } finally {
         deleteTopic(topic);
       }
@@ -510,18 +523,18 @@ public class SendAndReadTests extends AbstractBaseTest {
     public void doAssert(Consumer<TopicMessageDTO> msgAssert) {
       String topic = createTopicAndCreateSchemas();
       try {
-        clusterService.sendMessage(LOCAL, topic, msgToSend).block();
-        TopicMessageDTO polled = clusterService.getMessages(
-            LOCAL,
-            topic,
-            new ConsumerPosition(
-                SeekTypeDTO.BEGINNING,
-                Map.of(new TopicPartition(topic, 0), 0L),
-                SeekDirectionDTO.FORWARD
-            ),
-            null,
-            1
-        ).filter(e -> e.getType().equals(TopicMessageEventDTO.TypeEnum.MESSAGE))
+        messagesService.sendMessage(targetCluster, topic, msgToSend).block();
+        TopicMessageDTO polled = messagesService.loadMessages(
+                targetCluster,
+                topic,
+                new ConsumerPosition(
+                    SeekTypeDTO.BEGINNING,
+                    Map.of(new TopicPartition(topic, 0), 0L),
+                    SeekDirectionDTO.FORWARD
+                ),
+                null,
+                1
+            ).filter(e -> e.getType().equals(TopicMessageEventDTO.TypeEnum.MESSAGE))
             .map(TopicMessageEventDTO::getMessage)
             .blockLast(Duration.ofSeconds(5000));
 

kafka-ui-api/src/test/java/com/provectus/kafka/ui/service/TopicsServiceTest.java

@@ -0,0 +1,233 @@
+package com.provectus.kafka.ui.service;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import com.provectus.kafka.ui.mapper.ClusterMapper;
+import com.provectus.kafka.ui.model.InternalTopic;
+import com.provectus.kafka.ui.model.InternalTopicConfig;
+import com.provectus.kafka.ui.model.KafkaCluster;
+import com.provectus.kafka.ui.model.TopicColumnsToSortDTO;
+import com.provectus.kafka.ui.model.TopicDTO;
+import com.provectus.kafka.ui.serde.DeserializationService;
+import java.util.List;
+import java.util.Map;
+import java.util.Objects;
+import java.util.Optional;
+import java.util.function.Function;
+import java.util.stream.Collectors;
+import java.util.stream.IntStream;
+import org.apache.kafka.clients.admin.ConfigEntry;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mapstruct.factory.Mappers;
+import org.mockito.InjectMocks;
+import org.mockito.Mock;
+import org.mockito.Spy;
+import org.mockito.junit.jupiter.MockitoExtension;
+
+@ExtendWith(MockitoExtension.class)
+class TopicsServiceTest {
+  @Spy
+  private final ClusterMapper clusterMapper = Mappers.getMapper(ClusterMapper.class);
+  @InjectMocks
+  private TopicsService topicsService;
+  @Mock
+  private AdminClientService adminClientService;
+  @Mock
+  private ConsumerGroupService consumerGroupService;
+  @Mock
+  private ClustersStorage clustersStorage;
+
+  @Mock
+  private DeserializationService deserializationService;
+
+  @Test
+  public void shouldListFirst25Topics() {
+    final KafkaCluster cluster = KafkaCluster.builder()
+        .topics(
+            IntStream.rangeClosed(1, 100).boxed()
+                .map(Objects::toString)
+                .collect(Collectors.toMap(Function.identity(), e -> InternalTopic.builder()
+                    .partitions(Map.of())
+                    .name(e)
+                    .build()))
+        )
+        .build();
+
+    var topics = topicsService.getTopics(cluster,
+        Optional.empty(), Optional.empty(), Optional.empty(),
+        Optional.empty(), Optional.empty());
+    assertThat(topics.getPageCount()).isEqualTo(4);
+    assertThat(topics.getTopics()).hasSize(25);
+    assertThat(topics.getTopics()).map(TopicDTO::getName).isSorted();
+  }
+
+  @Test
+  public void shouldCalculateCorrectPageCountForNonDivisiblePageSize() {
+    var cluster = KafkaCluster.builder()
+        .topics(
+            IntStream.rangeClosed(1, 100).boxed()
+                .map(Objects::toString)
+                .collect(Collectors.toMap(Function.identity(), e -> InternalTopic.builder()
+                    .partitions(Map.of())
+                    .name(e)
+                    .build()))
+        )
+        .build();
+
+    var topics = topicsService.getTopics(cluster, Optional.of(4), Optional.of(33),
+        Optional.empty(), Optional.empty(), Optional.empty());
+    assertThat(topics.getPageCount()).isEqualTo(4);
+    assertThat(topics.getTopics()).hasSize(1)
+        .first().extracting(TopicDTO::getName).isEqualTo("99");
+  }
+
+  @Test
+  public void shouldCorrectlyHandleNonPositivePageNumberAndPageSize() {
+    var cluster = KafkaCluster.builder()
+        .topics(
+            IntStream.rangeClosed(1, 100).boxed()
+                .map(Objects::toString)
+                .collect(Collectors.toMap(Function.identity(), e -> InternalTopic.builder()
+                    .partitions(Map.of())
+                    .name(e)
+                    .build()))
+        )
+        .build();
+
+
+    var topics = topicsService.getTopics(cluster, Optional.of(0), Optional.of(-1),
+        Optional.empty(), Optional.empty(), Optional.empty());
+    assertThat(topics.getPageCount()).isEqualTo(4);
+    assertThat(topics.getTopics()).hasSize(25);
+    assertThat(topics.getTopics()).map(TopicDTO::getName).isSorted();
+  }
+
+  @Test
+  public void shouldListBotInternalAndNonInternalTopics() {
+    var cluster = KafkaCluster.builder()
+        .topics(
+            IntStream.rangeClosed(1, 100).boxed()
+                .map(Objects::toString)
+                .collect(Collectors.toMap(Function.identity(), e -> InternalTopic.builder()
+                    .partitions(Map.of())
+                    .name(e)
+                    .internal(Integer.parseInt(e) % 10 == 0)
+                    .build()))
+        )
+        .build();
+
+    var topics = topicsService.getTopics(cluster,
+        Optional.empty(), Optional.empty(), Optional.of(true),
+        Optional.empty(), Optional.empty());
+    assertThat(topics.getPageCount()).isEqualTo(4);
+    assertThat(topics.getTopics()).hasSize(25);
+    assertThat(topics.getTopics()).map(TopicDTO::getName).isSorted();
+  }
+
+
+  @Test
+  public void shouldListOnlyNonInternalTopics() {
+    var cluster = KafkaCluster.builder()
+        .topics(
+            IntStream.rangeClosed(1, 100).boxed()
+                .map(Objects::toString)
+                .collect(Collectors.toMap(Function.identity(), e -> InternalTopic.builder()
+                    .partitions(Map.of())
+                    .name(e)
+                    .internal(Integer.parseInt(e) % 10 == 0)
+                    .build()))
+        )
+        .build();
+
+    var topics = topicsService.getTopics(cluster,
+        Optional.empty(), Optional.empty(), Optional.of(true),
+        Optional.empty(), Optional.empty());
+    assertThat(topics.getPageCount()).isEqualTo(4);
+    assertThat(topics.getTopics()).hasSize(25);
+    assertThat(topics.getTopics()).map(TopicDTO::getName).isSorted();
+  }
+
+
+  @Test
+  public void shouldListOnlyTopicsContainingOne() {
+    var cluster = KafkaCluster.builder()
+        .topics(
+            IntStream.rangeClosed(1, 100).boxed()
+                .map(Objects::toString)
+                .collect(Collectors.toMap(Function.identity(), e -> InternalTopic.builder()
+                    .partitions(Map.of())
+                    .name(e)
+                    .build()))
+        )
+        .build();
+
+    var topics = topicsService.getTopics(cluster,
+        Optional.empty(), Optional.empty(), Optional.empty(),
+        Optional.of("1"), Optional.empty());
+    assertThat(topics.getPageCount()).isEqualTo(1);
+    assertThat(topics.getTopics()).hasSize(20);
+    assertThat(topics.getTopics()).map(TopicDTO::getName).isSorted();
+  }
+
+  @Test
+  public void shouldListTopicsOrderedByPartitionsCount() {
+    var cluster = KafkaCluster.builder()
+        .topics(
+            IntStream.rangeClosed(1, 100).boxed()
+                .map(Objects::toString)
+                .collect(Collectors.toMap(Function.identity(), e -> InternalTopic.builder()
+                    .partitions(Map.of())
+                    .name(e)
+                    .partitionCount(100 - Integer.parseInt(e))
+                    .build()))
+        )
+        .build();
+
+    var topics = topicsService.getTopics(cluster,
+        Optional.empty(), Optional.empty(), Optional.empty(),
+        Optional.empty(), Optional.of(TopicColumnsToSortDTO.TOTAL_PARTITIONS));
+    assertThat(topics.getPageCount()).isEqualTo(4);
+    assertThat(topics.getTopics()).hasSize(25);
+    assertThat(topics.getTopics()).map(TopicDTO::getPartitionCount).isSorted();
+  }
+
+  @Test
+  public void shouldRetrieveTopicConfigs() {
+    var cluster = KafkaCluster.builder()
+        .topics(
+            IntStream.rangeClosed(1, 100).boxed()
+                .map(Objects::toString)
+                .collect(Collectors.toMap(Function.identity(), e -> InternalTopic.builder()
+                    .name(e)
+                    .topicConfigs(
+                        List.of(InternalTopicConfig.builder()
+                            .name("testName")
+                            .value("testValue")
+                            .defaultValue("testDefaultValue")
+                            .source(ConfigEntry.ConfigSource.DEFAULT_CONFIG)
+                            .isReadOnly(true)
+                            .isSensitive(true)
+                            .synonyms(List.of())
+                            .build()
+                        )
+                    )
+                    .build()))
+        )
+        .build();
+
+    var configs = topicsService.getTopicConfigs(cluster, "1");
+    var topicConfig = configs.isPresent() ? configs.get().get(0) : null;
+
+    assertThat(configs.isPresent()).isTrue();
+    assertThat(topicConfig.getName()).isEqualTo("testName");
+    assertThat(topicConfig.getValue()).isEqualTo("testValue");
+    assertThat(topicConfig.getDefaultValue()).isEqualTo("testDefaultValue");
+    assertThat(topicConfig.getSource().getValue())
+            .isEqualTo(ConfigEntry.ConfigSource.DEFAULT_CONFIG.name());
+    assertThat(topicConfig.getSynonyms()).isNotNull();
+    assertThat(topicConfig.getIsReadOnly()).isTrue();
+    assertThat(topicConfig.getIsSensitive()).isTrue();
+  }
+
+}