01-cluster-join

cluster join/leave

Usage:

node1 is the node to start first, since you will see the address to join the cluster, please make a note.

$ go run node1.go
// => node1 at 192.168.0.25:7946

node2 is a node that only joins the cluster and finishes.
When you start up using the address of node1 above, the member information participating in the cluster is displayed.

$ go run node2.go --join 192.168.0.25:7946
// => Member: node1(192.168.0.25:7946)
// => Member: node2(192.168.0.25:7947)

node3 is a node that waits for a certain period of time after joining the cluster,
by exchanging the boot order of node2 and node3, you can see that participating members are changing.

# session1
$ go run node3.go --join 192.168.0.25:7946
// => Member: node1(192.168.0.25:7946)
// => Member: node3(192.168.0.25:7948)

# session2
$ go run node2.go --join 192.168.0.25:7946
// => Member: node1(192.168.0.25:7946)
// => Member: node2(192.168.0.25:7947)
// => Member: node3(192.168.0.25:7948)

Note:

Make sure memberlist.Config#Name (used as the node name) is unique.
Also, make sure BindPort and AdvertisePort are unique addresses.
It is used to communicate between nodes.

Configure:

this example using DefaultLocalConfig because it is intended for testing in the local environment.
If you want to test over the LAN/WAN network please set the appropriate Timeout / Interval.

conf := memberlist.DefaultLocalConfig()
conf.Name = "node1"
conf.BindAddr = "192.168.0.1"
conf.BindPort = 7901
conf.AdvertiseAddr = "192.168.0.1"
conf.AdvertisePort = 7901

list, err := memberlist.Create(conf)
if err != nil {
  log.Fatal(err)
}

see also - https://github.com/hashicorp/memberlist/blob/master/config.go