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raft is a golang library that provides a simple, clean, and idiomatic implementation of the Raft consensus protocol

License: MIT License

Makefile 0.57% Go 99.43%

golang go raft-consensus-algorithm raft write-ahead-log consensus raft-algorithm raft-protocol

raft's People

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warmchang penglq franklee0817 linka-cloud lemon-mint aderouineau a-guldborg fredpetersen mralexzee asynxc rakoo kotyara85 mehrdadjalili linkypi

raft's Issues

Guide on how to use this library with Kubernetes nodes discovery

Hello @shaj13 @aderouineau and @fredpetersen

I would like you to help provide guides on how to use this library on kubernetes where one can make use of the k8 api to discover pods and start a cluster.

Thanks

Extend grpc api

Hi @shaj13 ,
Looks like current gprc protos do not expose cluster management apis, for example remove failed node from the cluster.
Are there any plans on doing so?
Thank you

Production fitness

Hello @shaj13

Thanks for this great library. It has helped a lot understanding the etcd raft. However I would like to know whether this library has been used in production already.

TODO

add tcp rpc
check the conf change v2
Repair wall
add more logs.

Log is being applied on restart

Hello,
Is it an expected behavior?
After a node is restarted I see it fetches all the data from the leader
I'd expect it to get only the diff
Thanks

data sharding and gossip example

Hello @shaj13 can you please provide an example of data sharding and gossip that you stated in the multi-raft example?
Thanks

Nodes try to self connect when given predefined config

Hi there and thanks for sharing this project. I'm keen to introduce Raft into one of my projects in which there is a predefined cluster. During boot I'm getting the follower error on 2 of the three nodes:

panic: raft.membership: attempted to send msg to local member; should never happen

Here is the relevant code

func raftInit() {
	raftgrpc.Register(
		raftgrpc.WithDialOptions(grpc.WithInsecure()),
	)
	fsm = newstateMachine()
	node = raft.NewNode(fsm, transport.GRPC)
	raftServer = grpc.NewServer()
	raftgrpc.RegisterHandler(raftServer, node.Handler())

	m1 := raft.RawMember{ID: 1, Address: "host1:8081"}
	m2 := raft.RawMember{ID: 2, Address: "host2:8081"}
	m3 := raft.RawMember{ID: 3, Address: "host3:8081"}

	go func() {
		lis, err := net.Listen("tcp", ":8081")
		if err != nil {
			log.Fatal(err)
		}

		err = raftServer.Serve(lis)
		if err != nil {
			log.Fatal(err)
		}
	}()

  go func() {
	err := node.Start(raft.WithInitCluster(), raft.WithMembers(m1, m2, m3) )
                 if err != nil {
			log.Fatal(err)
		}
	}()
}

Not sure if this is misconfigured on my side or if there's an issue here. Would greatly appreciate you assistance.

Remove dead node

Is it possible to remove dead node from the cluster?
RemoveMember seems to be just marking node as removed
Thanks

How do I get notified of the change of leader?

I want to implement a distributed KV system with data sharding based on consistent hash , which involves the need to re-shard and transfer the cluster data after the cluster leader changes.I see that etcd does not provide a notification mechanism, but hashiCorp/raft does provide LeaderCh and NotifyCh to actively notify the application layer that the leader has changed.

In the implementation of this system, in addition to the above functions, a preVote function is required, but this function is not implemented in hashicorp/raft. So eventually I have to resort to etcd/raft. So I'd like to ask if you have that notification mechanism in your implementation of raft, or if there are other better suggestions

How to make use of node name as node id instead of integer but string

Hello I observed the node id are integer meanwhile using platform like kubernetes we can make use of the node name. Any recommendation on this will be helpful

Got rpc error: code = Unimplemented desc = unexpected HTTP status code received from server: 404 (Not Found)

Hello @shaj13

I am getting the following error:

ERROR: raft.membership: sending message to member 24669d2775c8b223: rpc error: code = Unimplemented desc = unexpected HTTP status code received from server: 404 (Not Found); transport: received unexpected content-type "text/plain; charset=utf-8"

I am running the application on k8 with a replica of 2.

These are the logs from the two Pods:

Pod-1:

{"level":"debug","ts":1683374970.9820142,"msg":"raft node URL=:3100"}
{"level":"debug","ts":1683374972.0948684,"msg":"kubernetes has discovered 1 nodes"}
2023/05/06 12:09:32 INFO: 61cca80dec1edadd switched to configuration voters=()
2023/05/06 12:09:32 INFO: 61cca80dec1edadd became follower at term 0
2023/05/06 12:09:32 INFO: newRaft 61cca80dec1edadd [peers: [], term: 0, commit: 0, applied: 0, lastindex: 0, lastterm: 0]
2023/05/06 12:09:32 INFO: 61cca80dec1edadd became follower at term 1
2023/05/06 12:09:32 INFO: 61cca80dec1edadd switched to configuration voters=(7047192294677469917)
2023/05/06 12:09:32 INFO: 61cca80dec1edadd switched to configuration voters=(7047192294677469917)
2023/05/06 12:09:33 INFO: 61cca80dec1edadd is starting a new election at term 1
2023/05/06 12:09:33 INFO: 61cca80dec1edadd became candidate at term 2
2023/05/06 12:09:33 INFO: 61cca80dec1edadd received MsgVoteResp from 61cca80dec1edadd at term 2
2023/05/06 12:09:33 INFO: 61cca80dec1edadd became leader at term 2
2023/05/06 12:09:33 INFO: raft.node: 61cca80dec1edadd elected leader 61cca80dec1edadd at term 2
2023/05/06 12:10:00 INFO: 61cca80dec1edadd switched to configuration voters=(2622956625795265059 7047192294677469917)
2023/05/06 12:10:01 ERROR: raft.membership: sending message to member 24669d2775c8b223: rpc error: code = Unimplemented desc = unexpected HTTP status code received from server: 404 (Not Found); transport: received unexpected content-type "text/plain; charset=utf-8"

Pod-2:

{"level":"debug","ts":1683374999.3820262,"msg":"raft node URL=:3100"}
{"level":"debug","ts":1683375000.8786376,"msg":"kubernetes has discovered 2 nodes"}
2023/05/06 12:10:01 INFO: 24669d2775c8b223 switched to configuration voters=()
2023/05/06 12:10:01 INFO: 24669d2775c8b223 became follower at term 0
2023/05/06 12:10:01 INFO: newRaft 24669d2775c8b223 [peers: [], term: 0, commit: 0, applied: 0, lastindex: 0, lastterm: 0]
2023/05/06 12:10:01 INFO: 24669d2775c8b223 became follower at term 1
2023/05/06 12:10:01 INFO: 24669d2775c8b223 switched to configuration voters=(2622956625795265059)
2023/05/06 12:10:01 INFO: 24669d2775c8b223 switched to configuration voters=(2622956625795265059 7047192294677469917)
2023/05/06 12:10:01 INFO: 24669d2775c8b223 switched to configuration voters=(2622956625795265059 7047192294677469917)
2023/05/06 12:10:01 INFO: 24669d2775c8b223 switched to configuration voters=()
2023/05/06 12:10:01 INFO: 24669d2775c8b223 became follower at term 0
2023/05/06 12:10:01 INFO: newRaft 24669d2775c8b223 [peers: [], term: 0, commit: 0, applied: 0, lastindex: 0, lastterm: 0]

I am sure I am doing something wrong

example cannot work under http protocol

I found there's a critical error in transport.Dialer while using transport.HTTP instead of transport.GRPC. The address parameter is like 127.0.0.1:8080. rafthttp.Dialer while pass this address to rafthttp.client thus problems will happen when the leader is trying to communicate with followers. rafthttp.client.Message proceed client request via http.NewRequestWithContext in rafthttp.client.requestProto method. Because the scheme of URL is missing from which we passed (127.0.0.1:8080) in the dialer.

More detail please see net/url.Parse. URL schema is required.