moby/libnetwork/networkdb/networkdb_test.go

package networkdb

import (
	"flag"
	"fmt"
	"io/ioutil"
	"log"
	"net"
	"os"
	"sync/atomic"
	"testing"
	"time"

	"github.com/docker/docker/pkg/stringid"
	"github.com/docker/go-events"
	"github.com/hashicorp/memberlist"
	"github.com/sirupsen/logrus"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

var (
	dbPort             int32 = 10000
	runningInContainer       = flag.Bool("incontainer", false, "Indicates if the test is running in a container")
)

func TestMain(m *testing.M) {
	ioutil.WriteFile("/proc/sys/net/ipv6/conf/lo/disable_ipv6", []byte{'0', '\n'}, 0644)
	logrus.SetLevel(logrus.ErrorLevel)
	os.Exit(m.Run())
}

func createNetworkDBInstances(t *testing.T, num int, namePrefix string, conf *Config) []*NetworkDB {
	var dbs []*NetworkDB
	for i := 0; i < num; i++ {
		localConfig := *conf
		localConfig.Hostname = fmt.Sprintf("%s%d", namePrefix, i+1)
		localConfig.NodeID = stringid.TruncateID(stringid.GenerateRandomID())
		localConfig.BindPort = int(atomic.AddInt32(&dbPort, 1))
		db, err := New(&localConfig)
		require.NoError(t, err)

		if i != 0 {
			err = db.Join([]string{fmt.Sprintf("localhost:%d", db.config.BindPort-1)})
			assert.NoError(t, err)
		}

		dbs = append(dbs, db)
	}

	// Check that the cluster is properly created
	for i := 0; i < num; i++ {
		if num != len(dbs[i].ClusterPeers()) {
			t.Fatalf("Number of nodes for %s into the cluster does not match %d != %d",
				dbs[i].config.Hostname, num, len(dbs[i].ClusterPeers()))
		}
	}

	return dbs
}

func closeNetworkDBInstances(dbs []*NetworkDB) {
	log.Print("Closing DB instances...")
	for _, db := range dbs {
		db.Close()
	}
}

func (db *NetworkDB) verifyNodeExistence(t *testing.T, node string, present bool) {
	for i := 0; i < 80; i++ {
		db.RLock()
		_, ok := db.nodes[node]
		db.RUnlock()
		if present && ok {
			return
		}

		if !present && !ok {
			return
		}

		time.Sleep(50 * time.Millisecond)
	}

	assert.Fail(t, fmt.Sprintf("%v(%v): Node existence verification for node %s failed", db.config.Hostname, db.config.NodeID, node))
}

func (db *NetworkDB) verifyNetworkExistence(t *testing.T, node string, id string, present bool) {
	for i := 0; i < 80; i++ {
		db.RLock()
		nn, nnok := db.networks[node]
		db.RUnlock()
		if nnok {
			n, ok := nn[id]
			if present && ok {
				return
			}

			if !present &&
				((ok && n.leaving) ||
					!ok) {
				return
			}
		}

		time.Sleep(50 * time.Millisecond)
	}

	assert.Fail(t, "Network existence verification failed")
}

func (db *NetworkDB) verifyEntryExistence(t *testing.T, tname, nid, key, value string, present bool) {
	n := 80
	for i := 0; i < n; i++ {
		entry, err := db.getEntry(tname, nid, key)
		if present && err == nil && string(entry.value) == value {
			return
		}

		if !present &&
			((err == nil && entry.deleting) ||
				(err != nil)) {
			return
		}

		if i == n-1 && !present && err != nil {
			return
		}

		time.Sleep(50 * time.Millisecond)
	}

	assert.Fail(t, fmt.Sprintf("Entry existence verification test failed for %v(%v)", db.config.Hostname, db.config.NodeID))
}

func testWatch(t *testing.T, ch chan events.Event, ev interface{}, tname, nid, key, value string) {
	select {
	case rcvdEv := <-ch:
		assert.Equal(t, fmt.Sprintf("%T", rcvdEv), fmt.Sprintf("%T", ev))
		switch rcvdEv.(type) {
		case CreateEvent:
			assert.Equal(t, tname, rcvdEv.(CreateEvent).Table)
			assert.Equal(t, nid, rcvdEv.(CreateEvent).NetworkID)
			assert.Equal(t, key, rcvdEv.(CreateEvent).Key)
			assert.Equal(t, value, string(rcvdEv.(CreateEvent).Value))
		case UpdateEvent:
			assert.Equal(t, tname, rcvdEv.(UpdateEvent).Table)
			assert.Equal(t, nid, rcvdEv.(UpdateEvent).NetworkID)
			assert.Equal(t, key, rcvdEv.(UpdateEvent).Key)
			assert.Equal(t, value, string(rcvdEv.(UpdateEvent).Value))
		case DeleteEvent:
			assert.Equal(t, tname, rcvdEv.(DeleteEvent).Table)
			assert.Equal(t, nid, rcvdEv.(DeleteEvent).NetworkID)
			assert.Equal(t, key, rcvdEv.(DeleteEvent).Key)
		}
	case <-time.After(time.Second):
		t.Fail()
		return
	}
}

func TestNetworkDBSimple(t *testing.T) {
	dbs := createNetworkDBInstances(t, 2, "node", DefaultConfig())
	closeNetworkDBInstances(dbs)
}

func TestNetworkDBJoinLeaveNetwork(t *testing.T) {
	dbs := createNetworkDBInstances(t, 2, "node", DefaultConfig())

	err := dbs[0].JoinNetwork("network1")
	assert.NoError(t, err)

	dbs[1].verifyNetworkExistence(t, dbs[0].config.NodeID, "network1", true)

	err = dbs[0].LeaveNetwork("network1")
	assert.NoError(t, err)

	dbs[1].verifyNetworkExistence(t, dbs[0].config.NodeID, "network1", false)
	closeNetworkDBInstances(dbs)
}

func TestNetworkDBJoinLeaveNetworks(t *testing.T) {
	dbs := createNetworkDBInstances(t, 2, "node", DefaultConfig())

	n := 10
	for i := 1; i <= n; i++ {
		err := dbs[0].JoinNetwork(fmt.Sprintf("network0%d", i))
		assert.NoError(t, err)
	}

	for i := 1; i <= n; i++ {
		err := dbs[1].JoinNetwork(fmt.Sprintf("network1%d", i))
		assert.NoError(t, err)
	}

	for i := 1; i <= n; i++ {
		dbs[1].verifyNetworkExistence(t, dbs[0].config.NodeID, fmt.Sprintf("network0%d", i), true)
	}

	for i := 1; i <= n; i++ {
		dbs[0].verifyNetworkExistence(t, dbs[1].config.NodeID, fmt.Sprintf("network1%d", i), true)
	}

	for i := 1; i <= n; i++ {
		err := dbs[0].LeaveNetwork(fmt.Sprintf("network0%d", i))
		assert.NoError(t, err)
	}

	for i := 1; i <= n; i++ {
		err := dbs[1].LeaveNetwork(fmt.Sprintf("network1%d", i))
		assert.NoError(t, err)
	}

	for i := 1; i <= n; i++ {
		dbs[1].verifyNetworkExistence(t, dbs[0].config.NodeID, fmt.Sprintf("network0%d", i), false)
	}

	for i := 1; i <= n; i++ {
		dbs[0].verifyNetworkExistence(t, dbs[1].config.NodeID, fmt.Sprintf("network1%d", i), false)
	}

	closeNetworkDBInstances(dbs)
}

func TestNetworkDBCRUDTableEntry(t *testing.T) {
	dbs := createNetworkDBInstances(t, 3, "node", DefaultConfig())

	err := dbs[0].JoinNetwork("network1")
	assert.NoError(t, err)

	dbs[1].verifyNetworkExistence(t, dbs[0].config.NodeID, "network1", true)

	err = dbs[1].JoinNetwork("network1")
	assert.NoError(t, err)

	err = dbs[0].CreateEntry("test_table", "network1", "test_key", []byte("test_value"))
	assert.NoError(t, err)

	dbs[1].verifyEntryExistence(t, "test_table", "network1", "test_key", "test_value", true)
	dbs[2].verifyEntryExistence(t, "test_table", "network1", "test_key", "test_value", false)

	err = dbs[0].UpdateEntry("test_table", "network1", "test_key", []byte("test_updated_value"))
	assert.NoError(t, err)

	dbs[1].verifyEntryExistence(t, "test_table", "network1", "test_key", "test_updated_value", true)

	err = dbs[0].DeleteEntry("test_table", "network1", "test_key")
	assert.NoError(t, err)

	dbs[1].verifyEntryExistence(t, "test_table", "network1", "test_key", "", false)

	closeNetworkDBInstances(dbs)
}

func TestNetworkDBCRUDTableEntries(t *testing.T) {
	dbs := createNetworkDBInstances(t, 2, "node", DefaultConfig())

	err := dbs[0].JoinNetwork("network1")
	assert.NoError(t, err)

	dbs[1].verifyNetworkExistence(t, dbs[0].config.NodeID, "network1", true)

	err = dbs[1].JoinNetwork("network1")
	assert.NoError(t, err)

	n := 10
	for i := 1; i <= n; i++ {
		err = dbs[0].CreateEntry("test_table", "network1",
			fmt.Sprintf("test_key0%d", i),
			[]byte(fmt.Sprintf("test_value0%d", i)))
		assert.NoError(t, err)
	}

	for i := 1; i <= n; i++ {
		err = dbs[1].CreateEntry("test_table", "network1",
			fmt.Sprintf("test_key1%d", i),
			[]byte(fmt.Sprintf("test_value1%d", i)))
		assert.NoError(t, err)
	}

	for i := 1; i <= n; i++ {
		dbs[0].verifyEntryExistence(t, "test_table", "network1",
			fmt.Sprintf("test_key1%d", i),
			fmt.Sprintf("test_value1%d", i), true)
		assert.NoError(t, err)
	}

	for i := 1; i <= n; i++ {
		dbs[1].verifyEntryExistence(t, "test_table", "network1",
			fmt.Sprintf("test_key0%d", i),
			fmt.Sprintf("test_value0%d", i), true)
		assert.NoError(t, err)
	}

	// Verify deletes
	for i := 1; i <= n; i++ {
		err = dbs[0].DeleteEntry("test_table", "network1",
			fmt.Sprintf("test_key0%d", i))
		assert.NoError(t, err)
	}

	for i := 1; i <= n; i++ {
		err = dbs[1].DeleteEntry("test_table", "network1",
			fmt.Sprintf("test_key1%d", i))
		assert.NoError(t, err)
	}

	for i := 1; i <= n; i++ {
		dbs[0].verifyEntryExistence(t, "test_table", "network1",
			fmt.Sprintf("test_key1%d", i), "", false)
		assert.NoError(t, err)
	}

	for i := 1; i <= n; i++ {
		dbs[1].verifyEntryExistence(t, "test_table", "network1",
			fmt.Sprintf("test_key0%d", i), "", false)
		assert.NoError(t, err)
	}

	closeNetworkDBInstances(dbs)
}

func TestNetworkDBNodeLeave(t *testing.T) {
	dbs := createNetworkDBInstances(t, 2, "node", DefaultConfig())

	err := dbs[0].JoinNetwork("network1")
	assert.NoError(t, err)

	err = dbs[1].JoinNetwork("network1")
	assert.NoError(t, err)

	err = dbs[0].CreateEntry("test_table", "network1", "test_key", []byte("test_value"))
	assert.NoError(t, err)

	dbs[1].verifyEntryExistence(t, "test_table", "network1", "test_key", "test_value", true)

	dbs[0].Close()
	dbs[1].verifyEntryExistence(t, "test_table", "network1", "test_key", "test_value", false)
	dbs[1].Close()
}

func TestNetworkDBWatch(t *testing.T) {
	dbs := createNetworkDBInstances(t, 2, "node", DefaultConfig())
	err := dbs[0].JoinNetwork("network1")
	assert.NoError(t, err)

	err = dbs[1].JoinNetwork("network1")
	assert.NoError(t, err)

	ch, cancel := dbs[1].Watch("", "", "")

	err = dbs[0].CreateEntry("test_table", "network1", "test_key", []byte("test_value"))
	assert.NoError(t, err)

	testWatch(t, ch.C, CreateEvent{}, "test_table", "network1", "test_key", "test_value")

	err = dbs[0].UpdateEntry("test_table", "network1", "test_key", []byte("test_updated_value"))
	assert.NoError(t, err)

	testWatch(t, ch.C, UpdateEvent{}, "test_table", "network1", "test_key", "test_updated_value")

	err = dbs[0].DeleteEntry("test_table", "network1", "test_key")
	assert.NoError(t, err)

	testWatch(t, ch.C, DeleteEvent{}, "test_table", "network1", "test_key", "")

	cancel()
	closeNetworkDBInstances(dbs)
}

func TestNetworkDBBulkSync(t *testing.T) {
	dbs := createNetworkDBInstances(t, 2, "node", DefaultConfig())

	err := dbs[0].JoinNetwork("network1")
	assert.NoError(t, err)

	dbs[1].verifyNetworkExistence(t, dbs[0].config.NodeID, "network1", true)

	n := 1000
	for i := 1; i <= n; i++ {
		err = dbs[0].CreateEntry("test_table", "network1",
			fmt.Sprintf("test_key0%d", i),
			[]byte(fmt.Sprintf("test_value0%d", i)))
		assert.NoError(t, err)
	}

	err = dbs[1].JoinNetwork("network1")
	assert.NoError(t, err)

	dbs[0].verifyNetworkExistence(t, dbs[1].config.NodeID, "network1", true)

	for i := 1; i <= n; i++ {
		dbs[1].verifyEntryExistence(t, "test_table", "network1",
			fmt.Sprintf("test_key0%d", i),
			fmt.Sprintf("test_value0%d", i), true)
		assert.NoError(t, err)
	}

	closeNetworkDBInstances(dbs)
}

func TestNetworkDBCRUDMediumCluster(t *testing.T) {
	n := 5

	dbs := createNetworkDBInstances(t, n, "node", DefaultConfig())

	for i := 0; i < n; i++ {
		for j := 0; j < n; j++ {
			if i == j {
				continue
			}

			dbs[i].verifyNodeExistence(t, dbs[j].config.NodeID, true)
		}
	}

	for i := 0; i < n; i++ {
		err := dbs[i].JoinNetwork("network1")
		assert.NoError(t, err)
	}

	for i := 0; i < n; i++ {
		for j := 0; j < n; j++ {
			dbs[i].verifyNetworkExistence(t, dbs[j].config.NodeID, "network1", true)
		}
	}

	err := dbs[0].CreateEntry("test_table", "network1", "test_key", []byte("test_value"))
	assert.NoError(t, err)

	for i := 1; i < n; i++ {
		dbs[i].verifyEntryExistence(t, "test_table", "network1", "test_key", "test_value", true)
	}

	err = dbs[0].UpdateEntry("test_table", "network1", "test_key", []byte("test_updated_value"))
	assert.NoError(t, err)

	for i := 1; i < n; i++ {
		dbs[i].verifyEntryExistence(t, "test_table", "network1", "test_key", "test_updated_value", true)
	}

	err = dbs[0].DeleteEntry("test_table", "network1", "test_key")
	assert.NoError(t, err)

	for i := 1; i < n; i++ {
		dbs[i].verifyEntryExistence(t, "test_table", "network1", "test_key", "", false)
	}

	closeNetworkDBInstances(dbs)
}

func TestNetworkDBNodeJoinLeaveIteration(t *testing.T) {
	maxRetry := 5
	dbs := createNetworkDBInstances(t, 2, "node", DefaultConfig())

	// Single node Join/Leave
	err := dbs[0].JoinNetwork("network1")
	assert.NoError(t, err)

	if len(dbs[0].networkNodes["network1"]) != 1 {
		t.Fatalf("The networkNodes list has to have be 1 instead of %d", len(dbs[0].networkNodes["network1"]))
	}

	err = dbs[0].LeaveNetwork("network1")
	assert.NoError(t, err)

	if len(dbs[0].networkNodes["network1"]) != 0 {
		t.Fatalf("The networkNodes list has to have be 0 instead of %d", len(dbs[0].networkNodes["network1"]))
	}

	// Multiple nodes Join/Leave
	err = dbs[0].JoinNetwork("network1")
	assert.NoError(t, err)

	err = dbs[1].JoinNetwork("network1")
	assert.NoError(t, err)

	// Wait for the propagation on db[0]
	for i := 0; i < maxRetry; i++ {
		if len(dbs[0].networkNodes["network1"]) == 2 {
			break
		}
		time.Sleep(1 * time.Second)
	}
	if len(dbs[0].networkNodes["network1"]) != 2 {
		t.Fatalf("The networkNodes list has to have be 2 instead of %d - %v", len(dbs[0].networkNodes["network1"]), dbs[0].networkNodes["network1"])
	}
	if n, ok := dbs[0].networks[dbs[0].config.NodeID]["network1"]; !ok || n.leaving {
		t.Fatalf("The network should not be marked as leaving:%t", n.leaving)
	}

	// Wait for the propagation on db[1]
	for i := 0; i < maxRetry; i++ {
		if len(dbs[1].networkNodes["network1"]) == 2 {
			break
		}
		time.Sleep(1 * time.Second)
	}
	if len(dbs[1].networkNodes["network1"]) != 2 {
		t.Fatalf("The networkNodes list has to have be 2 instead of %d - %v", len(dbs[1].networkNodes["network1"]), dbs[1].networkNodes["network1"])
	}
	if n, ok := dbs[1].networks[dbs[1].config.NodeID]["network1"]; !ok || n.leaving {
		t.Fatalf("The network should not be marked as leaving:%t", n.leaving)
	}

	// Try a quick leave/join
	err = dbs[0].LeaveNetwork("network1")
	assert.NoError(t, err)
	err = dbs[0].JoinNetwork("network1")
	assert.NoError(t, err)

	for i := 0; i < maxRetry; i++ {
		if len(dbs[0].networkNodes["network1"]) == 2 {
			break
		}
		time.Sleep(1 * time.Second)
	}
	if len(dbs[0].networkNodes["network1"]) != 2 {
		t.Fatalf("The networkNodes list has to have be 2 instead of %d - %v", len(dbs[0].networkNodes["network1"]), dbs[0].networkNodes["network1"])
	}

	for i := 0; i < maxRetry; i++ {
		if len(dbs[1].networkNodes["network1"]) == 2 {
			break
		}
		time.Sleep(1 * time.Second)
	}
	if len(dbs[1].networkNodes["network1"]) != 2 {
		t.Fatalf("The networkNodes list has to have be 2 instead of %d - %v", len(dbs[1].networkNodes["network1"]), dbs[1].networkNodes["network1"])
	}

	closeNetworkDBInstances(dbs)
}

func TestNetworkDBGarbageCollection(t *testing.T) {
	keysWriteDelete := 5
	config := DefaultConfig()
	config.reapEntryInterval = 30 * time.Second
	config.StatsPrintPeriod = 15 * time.Second

	dbs := createNetworkDBInstances(t, 3, "node", config)

	// 2 Nodes join network
	err := dbs[0].JoinNetwork("network1")
	assert.NoError(t, err)

	err = dbs[1].JoinNetwork("network1")
	assert.NoError(t, err)

	for i := 0; i < keysWriteDelete; i++ {
		err = dbs[i%2].CreateEntry("testTable", "network1", "key-"+string(i), []byte("value"))
		assert.NoError(t, err)
	}
	time.Sleep(time.Second)
	for i := 0; i < keysWriteDelete; i++ {
		err = dbs[i%2].DeleteEntry("testTable", "network1", "key-"+string(i))
		assert.NoError(t, err)
	}
	for i := 0; i < 2; i++ {
		assert.Equal(t, keysWriteDelete, dbs[i].networks[dbs[i].config.NodeID]["network1"].entriesNumber, "entries number should match")
	}

	// from this point the timer for the garbage collection started, wait 5 seconds and then join a new node
	time.Sleep(5 * time.Second)

	err = dbs[2].JoinNetwork("network1")
	assert.NoError(t, err)
	for i := 0; i < 3; i++ {
		assert.Equal(t, keysWriteDelete, dbs[i].networks[dbs[i].config.NodeID]["network1"].entriesNumber, "entries number should match")
	}
	// at this point the entries should had been all deleted
	time.Sleep(30 * time.Second)
	for i := 0; i < 3; i++ {
		assert.Equal(t, 0, dbs[i].networks[dbs[i].config.NodeID]["network1"].entriesNumber, "entries should had been garbage collected")
	}

	// make sure that entries are not coming back
	time.Sleep(15 * time.Second)
	for i := 0; i < 3; i++ {
		assert.Equal(t, 0, dbs[i].networks[dbs[i].config.NodeID]["network1"].entriesNumber, "entries should had been garbage collected")
	}

	closeNetworkDBInstances(dbs)
}

func TestFindNode(t *testing.T) {
	dbs := createNetworkDBInstances(t, 1, "node", DefaultConfig())

	dbs[0].nodes["active"] = &node{Node: memberlist.Node{Name: "active"}}
	dbs[0].failedNodes["failed"] = &node{Node: memberlist.Node{Name: "failed"}}
	dbs[0].leftNodes["left"] = &node{Node: memberlist.Node{Name: "left"}}

	// active nodes is 2 because the testing node is in the list
	assert.Equal(t, 2, len(dbs[0].nodes))
	assert.Equal(t, 1, len(dbs[0].failedNodes))
	assert.Equal(t, 1, len(dbs[0].leftNodes))

	n, currState, m := dbs[0].findNode("active")
	assert.NotNil(t, n)
	assert.Equal(t, "active", n.Name)
	assert.Equal(t, nodeActiveState, currState)
	assert.NotNil(t, m)
	// delete the entry manually
	delete(m, "active")

	// test if can be still find
	n, currState, m = dbs[0].findNode("active")
	assert.Nil(t, n)
	assert.Equal(t, nodeNotFound, currState)
	assert.Nil(t, m)

	n, currState, m = dbs[0].findNode("failed")
	assert.NotNil(t, n)
	assert.Equal(t, "failed", n.Name)
	assert.Equal(t, nodeFailedState, currState)
	assert.NotNil(t, m)

	// find and remove
	n, currState, m = dbs[0].findNode("left")
	assert.NotNil(t, n)
	assert.Equal(t, "left", n.Name)
	assert.Equal(t, nodeLeftState, currState)
	assert.NotNil(t, m)
	delete(m, "left")

	n, currState, m = dbs[0].findNode("left")
	assert.Nil(t, n)
	assert.Equal(t, nodeNotFound, currState)
	assert.Nil(t, m)

	closeNetworkDBInstances(dbs)
}

func TestChangeNodeState(t *testing.T) {
	dbs := createNetworkDBInstances(t, 1, "node", DefaultConfig())

	dbs[0].nodes["node1"] = &node{Node: memberlist.Node{Name: "node1"}}
	dbs[0].nodes["node2"] = &node{Node: memberlist.Node{Name: "node2"}}
	dbs[0].nodes["node3"] = &node{Node: memberlist.Node{Name: "node3"}}

	// active nodes is 4 because the testing node is in the list
	assert.Equal(t, 4, len(dbs[0].nodes))

	n, currState, m := dbs[0].findNode("node1")
	assert.NotNil(t, n)
	assert.Equal(t, nodeActiveState, currState)
	assert.Equal(t, "node1", n.Name)
	assert.NotNil(t, m)

	// node1 to failed
	dbs[0].changeNodeState("node1", nodeFailedState)

	n, currState, m = dbs[0].findNode("node1")
	assert.NotNil(t, n)
	assert.Equal(t, nodeFailedState, currState)
	assert.Equal(t, "node1", n.Name)
	assert.NotNil(t, m)
	assert.NotEqual(t, time.Duration(0), n.reapTime)

	// node1 back to active
	dbs[0].changeNodeState("node1", nodeActiveState)

	n, currState, m = dbs[0].findNode("node1")
	assert.NotNil(t, n)
	assert.Equal(t, nodeActiveState, currState)
	assert.Equal(t, "node1", n.Name)
	assert.NotNil(t, m)
	assert.Equal(t, time.Duration(0), n.reapTime)

	// node1 to left
	dbs[0].changeNodeState("node1", nodeLeftState)
	dbs[0].changeNodeState("node2", nodeLeftState)
	dbs[0].changeNodeState("node3", nodeLeftState)

	n, currState, m = dbs[0].findNode("node1")
	assert.NotNil(t, n)
	assert.Equal(t, nodeLeftState, currState)
	assert.Equal(t, "node1", n.Name)
	assert.NotNil(t, m)
	assert.NotEqual(t, time.Duration(0), n.reapTime)

	n, currState, m = dbs[0].findNode("node2")
	assert.NotNil(t, n)
	assert.Equal(t, nodeLeftState, currState)
	assert.Equal(t, "node2", n.Name)
	assert.NotNil(t, m)
	assert.NotEqual(t, time.Duration(0), n.reapTime)

	n, currState, m = dbs[0].findNode("node3")
	assert.NotNil(t, n)
	assert.Equal(t, nodeLeftState, currState)
	assert.Equal(t, "node3", n.Name)
	assert.NotNil(t, m)
	assert.NotEqual(t, time.Duration(0), n.reapTime)

	// active nodes is 1 because the testing node is in the list
	assert.Equal(t, 1, len(dbs[0].nodes))
	assert.Equal(t, 0, len(dbs[0].failedNodes))
	assert.Equal(t, 3, len(dbs[0].leftNodes))

	closeNetworkDBInstances(dbs)
}

func TestNodeReincarnation(t *testing.T) {
	dbs := createNetworkDBInstances(t, 1, "node", DefaultConfig())

	dbs[0].nodes["node1"] = &node{Node: memberlist.Node{Name: "node1", Addr: net.ParseIP("192.168.1.1")}}
	dbs[0].leftNodes["node2"] = &node{Node: memberlist.Node{Name: "node2", Addr: net.ParseIP("192.168.1.2")}}
	dbs[0].failedNodes["node3"] = &node{Node: memberlist.Node{Name: "node3", Addr: net.ParseIP("192.168.1.3")}}

	// active nodes is 2 because the testing node is in the list
	assert.Equal(t, 2, len(dbs[0].nodes))
	assert.Equal(t, 1, len(dbs[0].failedNodes))
	assert.Equal(t, 1, len(dbs[0].leftNodes))

	b := dbs[0].purgeReincarnation(&memberlist.Node{Name: "node4", Addr: net.ParseIP("192.168.1.1")})
	assert.True(t, b)
	dbs[0].nodes["node4"] = &node{Node: memberlist.Node{Name: "node4", Addr: net.ParseIP("192.168.1.1")}}

	b = dbs[0].purgeReincarnation(&memberlist.Node{Name: "node5", Addr: net.ParseIP("192.168.1.2")})
	assert.True(t, b)
	dbs[0].nodes["node5"] = &node{Node: memberlist.Node{Name: "node5", Addr: net.ParseIP("192.168.1.1")}}

	b = dbs[0].purgeReincarnation(&memberlist.Node{Name: "node6", Addr: net.ParseIP("192.168.1.3")})
	assert.True(t, b)
	dbs[0].nodes["node6"] = &node{Node: memberlist.Node{Name: "node6", Addr: net.ParseIP("192.168.1.1")}}

	b = dbs[0].purgeReincarnation(&memberlist.Node{Name: "node6", Addr: net.ParseIP("192.168.1.10")})
	assert.False(t, b)

	// active nodes is 1 because the testing node is in the list
	assert.Equal(t, 4, len(dbs[0].nodes))
	assert.Equal(t, 0, len(dbs[0].failedNodes))
	assert.Equal(t, 3, len(dbs[0].leftNodes))

	closeNetworkDBInstances(dbs)
}

func TestParallelCreate(t *testing.T) {
	dbs := createNetworkDBInstances(t, 1, "node", DefaultConfig())

	startCh := make(chan int)
	doneCh := make(chan error)
	var success int32
	for i := 0; i < 20; i++ {
		go func() {
			<-startCh
			err := dbs[0].CreateEntry("testTable", "testNetwork", "key", []byte("value"))
			if err == nil {
				atomic.AddInt32(&success, 1)
			}
			doneCh <- err
		}()
	}

	close(startCh)

	for i := 0; i < 20; i++ {
		<-doneCh
	}
	close(doneCh)
	// Only 1 write should have succeeded
	assert.Equal(t, int32(1), success)

	closeNetworkDBInstances(dbs)
}

func TestParallelDelete(t *testing.T) {
	dbs := createNetworkDBInstances(t, 1, "node", DefaultConfig())

	err := dbs[0].CreateEntry("testTable", "testNetwork", "key", []byte("value"))
	assert.NoError(t, err)

	startCh := make(chan int)
	doneCh := make(chan error)
	var success int32
	for i := 0; i < 20; i++ {
		go func() {
			<-startCh
			err := dbs[0].DeleteEntry("testTable", "testNetwork", "key")
			if err == nil {
				atomic.AddInt32(&success, 1)
			}
			doneCh <- err
		}()
	}

	close(startCh)

	for i := 0; i < 20; i++ {
		<-doneCh
	}
	close(doneCh)
	// Only 1 write should have succeeded
	assert.Equal(t, int32(1), success)

	closeNetworkDBInstances(dbs)
}