How to determine whether a raft node is the leader?

[garan82]

In my use case, there is some work that should only be done once and the result would be propagated to other nodes. How can I make sure that only one node does this work? I am thinking of having the leader to do it, but I dont see any doc on determining whether a raft node is the leader. Any suggestions? Thanks!

[mind1949]

In my use case, there is some work that should only be done once and the result would be propagated to other nodes. How can I make sure that only one node does this work? I am thinking of having the leader to do it, but I dont see any doc on determining whether a raft node is the leader. Any suggestions? Thanks!

If you are using raft package, Node.Status().RaftState.RaftState == StateLeader is your choice .

[SimFG]

There is an example in the benchmark. Hope it helps you.

etcd/tools/benchmark/cmd/util.go

Lines 43 to 67 in 4977877

	func mustFindLeaderEndpoints(c *clientv3.Client) {
	resp, lerr := c.MemberList(context.TODO())
	if lerr != nil {
	fmt.Fprintf(os.Stderr, "failed to get a member list: %s\n", lerr)
	os.Exit(1)
	}
	leaderId := uint64(0)
	for _, ep := range c.Endpoints() {
	if sresp, serr := c.Status(context.TODO(), ep); serr == nil {
	leaderId = sresp.Leader
	break
	}
	}
	for _, m := range resp.Members {
	if m.ID == leaderId {
	leaderEps = m.ClientURLs
	return
	}
	}
	fmt.Fprintf(os.Stderr, "failed to find a leader endpoint\n")
	os.Exit(1)
	}

[garan82]

Thank you all!