[Gateway] Better logging around node connectivity

1. Rename "heartbeat" -> "keepalive" to avoid confusion with other types of heartbeats.
2. Log node name alongside failed pings for easier debugging.

core/services/gateway/connectionmanager.go

@@ -27,9 +27,9 @@ import (
 	"github.com/smartcontractkit/chainlink/v2/core/utils"
 )
 
-var promHeartbeatsSent = promauto.NewGaugeVec(prometheus.GaugeOpts{
-	Name: "gateway_heartbeats_sent",
-	Help: "Metric to track the number of successful node heartbeates per DON",
+var promKeepalivesSent = promauto.NewGaugeVec(prometheus.GaugeOpts{
+	Name: "gateway_keepalives_sent",
+	Help: "Metric to track the number of successful keepalive ping messages per DON",
 }, []string{"don_id"})
 
 // ConnectionManager holds all connections between Gateway and Nodes.
@@ -77,6 +77,7 @@ type donConnectionManager struct {
 }
 
 type nodeState struct {
+	name string
 	conn network.WSConnectionWrapper
 }
 
@@ -107,10 +108,14 @@ func NewConnectionManager(gwConfig *config.GatewayConfig, clock utils.Clock, lgg
 			if ok {
 				return nil, fmt.Errorf("duplicate node address %s in DON %s", nodeAddress, donConfig.DonId)
 			}
-			nodes[nodeAddress] = &nodeState{conn: network.NewWSConnectionWrapper(lggr)}
-			if nodes[nodeAddress].conn == nil {
+			connWrapper := network.NewWSConnectionWrapper(lggr)
+			if connWrapper == nil {
 				return nil, fmt.Errorf("error creating WSConnectionWrapper for node %s", nodeAddress)
 			}
+			nodes[nodeAddress] = &nodeState{
+				name: nodeConfig.Name,
+				conn: connWrapper,
+			}
 		}
 		dons[donConfig.DonId] = &donConnectionManager{
 			donConfig:  &donConfig,
@@ -148,7 +153,7 @@ func (m *connectionManager) Start(ctx context.Context) error {
 				go donConnMgr.readLoop(nodeAddress, nodeState)
 			}
 			donConnMgr.closeWait.Add(1)
-			go donConnMgr.heartbeatLoop(m.config.HeartbeatIntervalSec)
+			go donConnMgr.keepaliveLoop(m.config.HeartbeatIntervalSec)
 		}
 		return m.wsServer.Start(ctx)
 	})
@@ -231,7 +236,7 @@ func (m *connectionManager) FinalizeHandshake(attemptId string, response []byte,
 	}
 	if conn != nil {
 		conn.SetPongHandler(func(data string) error {
-			m.lggr.Debugw("received heartbeat pong from node", "nodeAddress", attempt.nodeAddress)
+			m.lggr.Debugw("received keepalive pong from node", "nodeAddress", attempt.nodeAddress)
 			return nil
 		})
 	}
@@ -299,34 +304,34 @@ func (m *donConnectionManager) readLoop(nodeAddress string, nodeState *nodeState
 	}
 }
 
-func (m *donConnectionManager) heartbeatLoop(intervalSec uint32) {
+func (m *donConnectionManager) keepaliveLoop(intervalSec uint32) {
 	ctx, _ := m.shutdownCh.NewCtx()
 	defer m.closeWait.Done()
 
 	if intervalSec == 0 {
-		m.lggr.Error("heartbeat interval is 0, heartbeat disabled")
+		m.lggr.Errorw("keepalive interval is 0, keepalive disabled", "donID", m.donConfig.DonId)
 		return
 	}
-	m.lggr.Info("starting heartbeat loop")
+	m.lggr.Infow("starting keepalive loop", "donID", m.donConfig.DonId)
 
-	ticker := time.NewTicker(time.Duration(intervalSec) * time.Second)
-	defer ticker.Stop()
+	keepaliveTicker := time.NewTicker(time.Duration(intervalSec) * time.Second)
+	defer keepaliveTicker.Stop()
 
 	for {
 		select {
 		case <-m.shutdownCh:
 			return
-		case <-ticker.C:
+		case <-keepaliveTicker.C:
 			errorCount := 0
 			for nodeAddress, nodeState := range m.nodes {
 				err := nodeState.conn.Write(ctx, websocket.PingMessage, []byte{})
 				if err != nil {
-					m.lggr.Debugw("unable to send heartbeat to node", "nodeAddress", nodeAddress, "err", err)
+					m.lggr.Debugw("unable to send keepalive ping to node", "nodeAddress", nodeAddress, "name", nodeState.name, "donID", m.donConfig.DonId, "err", err)
 					errorCount++
 				}
 			}
-			promHeartbeatsSent.WithLabelValues(m.donConfig.DonId).Set(float64(len(m.nodes) - errorCount))
-			m.lggr.Infow("sent heartbeat to nodes", "donID", m.donConfig.DonId, "errCount", errorCount)
+			promKeepalivesSent.WithLabelValues(m.donConfig.DonId).Set(float64(len(m.nodes) - errorCount))
+			m.lggr.Infow("sent keepalive pings to nodes", "donID", m.donConfig.DonId, "errCount", errorCount)
 		}
 	}
 }

core/services/gateway/connectionmanager_test.go

@@ -227,3 +227,19 @@ func TestConnectionManager_SendToNode_Failures(t *testing.T) {
 	err = donMgr.SendToNode(testutils.Context(t), "some_other_node", message)
 	require.Error(t, err)
 }
+
+func TestConnectionManager_CleanStartClose(t *testing.T) {
+	t.Parallel()
+
+	config, _ := newTestConfig(t, 2)
+	config.ConnectionManagerConfig.HeartbeatIntervalSec = 1
+	clock := utils.NewFixedClock(time.Now())
+	mgr, err := gateway.NewConnectionManager(config, clock, logger.TestLogger(t))
+	require.NoError(t, err)
+
+	err = mgr.Start(testutils.Context(t))
+	require.NoError(t, err)
+
+	err = mgr.Close()
+	require.NoError(t, err)
+}