[server] Improve log (#1769)

## Description

## Tests

server/pkg/controller/embedding/delete.go

@@ -73,14 +73,19 @@ func (c *Controller) deleteEmbedding(qItem repo.QueueItem) {
 	}
 	ctxLogger.Infof("Deleting from all datacenters %v", datacenters)
 	for i := range datacenters {
-		err = c.ObjectCleanupController.DeleteAllObjectsWithPrefix(prefix, datacenters[i])
+		dc := datacenters[i]
+		err = c.ObjectCleanupController.DeleteAllObjectsWithPrefix(prefix, dc)
 		if err != nil {
-			ctxLogger.WithError(err).Errorf("Failed to delete all objects from %s", datacenters[i])
+			ctxLogger.WithError(err).
+				WithField("dc", dc).
+				Errorf("Failed to delete all objects from %s", datacenters[i])
 			return
 		} else {
 			removeErr := c.Repo.RemoveDatacenter(context.Background(), fileID, datacenters[i])
 			if removeErr != nil {
-				ctxLogger.WithError(removeErr).Error("Failed to remove datacenter from db")
+				ctxLogger.WithError(removeErr).
+					WithField("dc", dc).
+					Error("Failed to remove datacenter from db")
 				return
 			}
 		}

server/pkg/controller/object_cleanup.go

@@ -260,7 +260,10 @@ func (c *ObjectCleanupController) DeleteAllObjectsWithPrefix(prefix string, dc s
 		Prefix: &prefix,
 	})
 	if err != nil {
-		log.Error(err)
+		log.WithFields(log.Fields{
+			"prefix": prefix,
+			"dc":     dc,
+		}).WithError(err).Error("Failed to list objects")
 		return stacktrace.Propagate(err, "")
 	}
 	var keys []string
@@ -270,7 +273,10 @@ func (c *ObjectCleanupController) DeleteAllObjectsWithPrefix(prefix string, dc s
 	for _, key := range keys {
 		err = c.DeleteObjectFromDataCenter(key, dc)
 		if err != nil {
-			log.Error(err)
+			log.WithFields(log.Fields{
+				"object_key": key,
+				"dc":         dc,
+			}).WithError(err).Error("Failed to delete object")
 			return stacktrace.Propagate(err, "")
 		}
 	}