Multiple Memberlists on a single machine

[carterventures]

I apologize if I'm having a total brain fart here (stemming from either a Thanksgiving food coma or the fact that this is my first foray into go), but I'm attempting to launch two instances of a service using the Memberlist library on my local machine, using separate ports for Memberlist, but am hitting an error:

[ERR] Conflicting address for mbp-chrisc-lt. Mine: 192.168.206.249:8001 Theirs: 192.168.206.249:8002

Based on the block below (line 586) in the state.go file, it appears as though this configuration may not be supported by Memberlist:

 // Check if this address is different than the existing node
 if !reflect.DeepEqual([]byte(state.Addr), a.Addr) || state.Port != a.Port {
        m.logger.Printf("[ERR] Conflicting address for %s. Mine: %v:%d Theirs: %v:%d",
                        state.Name, state.Addr, state.Port, net.IP(a.Addr), a.Port)
        return
}

If I read that right, it will print that error and return if the two addresses are NOT the same OR the ports are NOT the same. Should it be the other way around?

[armon]

It is a bit confusing. Basically Memberlist requires that the mapping of node Name -> (Addr, Port) being unique. So it means you cannot have two nodes with the same name. Technically the (Addr, Port) tuple should also be unique but I don't think it generates an error for that. The problem is that both of your Memberlist nodes are advertising using the same name (which defaults to the hostname). All you need to do is provide a unique Name inside the Config object.

[armon]

You are probably calling DefaultConfig() which set's the name for you: https://github.com/hashicorp/memberlist/blob/master/memberlist.go#L185

[carterventures]

Ahh, that did it, thanks! After making the change to use a unique name, it's working just fine. Appreciate the quick response. Do you guys prefer questions like this to go to say, the Serf user group, or do issues on Github suffice?

[armon]

Issues on Github are fine. But if you prefer the user group, that works too.