Complete logic for sending coordinates

command/agent/agent.go

@@ -38,6 +38,9 @@ const (
 		"but no reason was provided. This is a default message."
 	defaultServiceMaintReason = "Maintenance mode is enabled for this " +
 		"service, but no reason was provided. This is a default message."
+
+	// An interval used to send network coordinates to servers
+	syncCoordinateStaggerIntv = 15 * time.Second
 )
 
 var (
@@ -557,19 +560,38 @@ func (a *Agent) ResumeSync() {
 	a.state.Resume()
 }
 
-// SendCoordinates starts a goroutine that periodically sends the local coordinate
+// SendCoordinates starts a loop that periodically sends the local coordinate
 // to a server
-func (a *Agent) SendCoordinates() {
-	var c coordinate.Coordinate
-	if a.config.Server {
-		c = a.server
-	}
-	req := structs.CoordinateUpdateRequest{
-		NodeSpecificRequest: NodeSpecificRequest{
-			Datacenter: a.config.Datacenter,
-			Node:       a.config.NodeName,
-		},
-		QueryOptions: structs.QueryOptions{Token: a.config.ACLToken},
+func (a *Agent) SendCoordinates(shutdownCh chan struct{}) {
+	for {
+		intv := aeScale(a.config.SyncCoordinateInterval, len(a.LANMembers()))
+		intv = intv + randomStagger(intv)
+		timer := time.After(intv)
+		select {
+		case <-timer:
+			var c coordinate.Coordinate
+			if a.config.Server {
+				c = a.server.GetLANCoordinate()
+			} else {
+				c = a.client.GetCoordinate()
+			}
+			req := structs.CoordinateUpdateRequest{
+				NodeSpecificRequest: NodeSpecificRequest{
+					Datacenter: a.config.Datacenter,
+					Node:       a.config.NodeName,
+				},
+				Op:           structs.CoordinateSet,
+				Coord:        c,
+				QueryOptions: structs.QueryOptions{Token: a.config.ACLToken},
+			}
+
+			var reply struct{}
+			if err := a.RPC("Coordinate.Update", &arg, &reply); err != nil {
+				a.logger.Printf("[ERR] coordinate update error: %s", err.Error())
+			}
+		case <-shutdownCh:
+			return
+		}
 	}
 }
 

command/agent/command.go

@@ -709,6 +709,9 @@ func (c *Command) Run(args []string) int {
 	errWanCh := make(chan struct{})
 	go c.retryJoinWan(config, errWanCh)
 
+	// Start sending network coordinates to servers
+	go c.agent.SendCoordinates(c.agent.shutdownCh)
+
 	// Wait for exit
 	return c.handleSignals(config, errCh, errWanCh)
 }

command/agent/config.go

@@ -372,6 +372,10 @@ type Config struct {
 	// representation of our state. Defaults to every 60s.
 	AEInterval time.Duration `mapstructure:"-" json:"-"`
 
+	// SyncCoordinateInterval controls the interval for sending network coordinates
+	// to servers.
+	SyncCoordinateInterval time.Duration `mapstructure:"-" json:"-"`
+
 	// Checks holds the provided check definitions
 	Checks []*CheckDefinition `mapstructure:"-" json:"-"`
 
@@ -466,6 +470,7 @@ func DefaultConfig() *Config {
 		Protocol:            consul.ProtocolVersionMax,
 		CheckUpdateInterval: 5 * time.Minute,
 		AEInterval:          time.Minute,
+		SyncCoordinateInterval: 15 * time.Second,
 		ACLTTL:              30 * time.Second,
 		ACLDownPolicy:       "extend-cache",
 		ACLDefaultPolicy:    "allow",

consul/client.go

@@ -12,6 +12,7 @@ import (
 	"time"
 
 	"github.com/hashicorp/consul/consul/structs"
+	"github.com/hashicorp/serf/coordinate"
 	"github.com/hashicorp/serf/serf"
 )
 
@@ -376,3 +377,8 @@ func (c *Client) Stats() map[string]map[string]string {
 	}
 	return stats
 }
+
+// GetCoordinate returns the network coordinate of the receiver
+func (c *Client) GetCoordinate() *coordinate.Coordinate {
+	return c.serf.GetCoordinate()
+}

consul/server.go

@@ -19,6 +19,7 @@ import (
 	"github.com/hashicorp/consul/tlsutil"
 	"github.com/hashicorp/raft"
 	"github.com/hashicorp/raft-boltdb"
+	"github.com/hashicorp/serf/coordinate"
 	"github.com/hashicorp/serf/serf"
 )
 
@@ -693,3 +694,8 @@ func (s *Server) Stats() map[string]map[string]string {
 	}
 	return stats
 }
+
+// GetLANCoordinate returns the network coordinate of the receiver
+func (s *Server) GetLANCoordinate() *coordinate.Coordinate {
+	return s.serfLAN.GetCoordinate()
+}