swimy

Simple, unambitious implementation of swimy: Scalable Weakly-consistent Infection-style Process Group Membership Protocol plus some improvements.

Usage

    cfg := swimy.DefaultConfig()
    cfg.OnJoin = func(addr net.Addr) {
    // do something with the notification
    }
    cfg.OnLeave = func(addr net.Addr) {
    // do something with the notification
    }
    ms1, err := swimy.New(cfg)
    if err != nil {
    //
    }
    defer ms1.Stop()
    
    // some other app
    ms2, err := swimy.New(nil) 
    if err != nil {
    //
    }
    defer ms2.Stop()
    err := ms2.Join(ctx, "127.0.0.1:54555") // existing known members to join the membership

Decisions

• Failure is immediately disseminated by multicast
  • using gossip style dissemination could have reduced msgs going around, yet reducing convergence speed.
• Gossip uses randomness rather than round-robin
  • round-robin may be added for probing to reduce time to detect failure

TODOs

• Implement lamport clock
• Instrument via otel & slog
• TCP conn. pooling per addr
• Add failure testing