diff --git a/cli/commands.go b/cli/commands.go index 73790935c9..d3d76d46f4 100644 --- a/cli/commands.go +++ b/cli/commands.go @@ -36,7 +36,7 @@ var ( Name: "join", ShortName: "j", Usage: "join a docker cluster", - Flags: []cli.Flag{flJoinAdvertise, flHeartBeat, flTTL, flDiscoveryOpt}, + Flags: []cli.Flag{flJoinAdvertise, flHeartBeat, flTTL, flJoinRandomDelay, flDiscoveryOpt}, Action: join, }, } diff --git a/cli/flags.go b/cli/flags.go index 6d783189e9..b7d4e617b4 100644 --- a/cli/flags.go +++ b/cli/flags.go @@ -32,6 +32,11 @@ var ( Usage: "Address of the Docker Engine joining the cluster. Swarm manager(s) MUST be able to reach the Docker Engine at this address.", EnvVar: "SWARM_ADVERTISE", } + flJoinRandomDelay = cli.StringFlag{ + Name: "joindelay", + Value: "0s", + Usage: "add a random delay in [0s,joindelay] to avoid synchronized registration", + } flManageAdvertise = cli.StringFlag{ Name: "advertise, addr", Usage: "Address of the swarm manager joining the cluster. Other swarm manager(s) MUST be able to reach the swarm manager at this address.", diff --git a/cli/join.go b/cli/join.go index f59c005f91..5de81276a8 100644 --- a/cli/join.go +++ b/cli/join.go @@ -29,6 +29,11 @@ func join(c *cli.Context) { log.Fatal("--advertise should be of the form ip:port or hostname:port") } + joinDelay, err := time.ParseDuration(c.String("joindelay")) + if err != nil { + log.Fatalf("invalid --joindelay: %v", err) + } + hb, err := time.ParseDuration(c.String("heartbeat")) if err != nil { log.Fatalf("invalid --heartbeat: %v", err) @@ -49,11 +54,13 @@ func join(c *cli.Context) { log.Fatal(err) } - // add a random delay [0,hb) at start to avoid synchronized registration - r := rand.New(rand.NewSource(time.Now().UTC().UnixNano())) - delay := time.Duration(r.Int63n(int64(hb))) - log.Infof("Add a random delay %s to avoid synchronized registration", delay) - time.Sleep(delay) + // add a random delay between 0s and joinDelay at start to avoid synchronized registration + if joinDelay > 0 { + r := rand.New(rand.NewSource(time.Now().UTC().UnixNano())) + delay := time.Duration(r.Int63n(int64(joinDelay))) + log.Infof("Add a random delay %s to avoid synchronized registration", delay) + time.Sleep(delay) + } for { log.WithFields(log.Fields{"addr": addr, "discovery": dflag}).Infof("Registering on the discovery service every %s...", hb)