Question: Dynamic routees in group router

[pavelsmejkal]

Hi, i have one question about routing group. I was studying how the routers are written since I wanted to help with consistent hashing issue.

Just want to ask what is the intention about group routers. Are they static by any purpose? You have mentioned consul.io in readme. That is exactly what i want to use for clustering. But how to incorporate it to gam ?

Only way currently is to create front facing structure that will implement Tell(message interface{}) and forward messages to some group router. If anything changes in consul network this struct will re-create group router and stop old remote pids. Is that something that you are proposing? Or i have missed something.

It would be awesome if group routers would have ability to change routees in runtime.

[rogeralsing]

The easiest way to do what you want right now, would be to create an actor that talks to consul, to find the PID's for each routee.

e.g.

Sender -> Consul Proxy Actor -> Routee

That way, when you send a message, send it to the consul proxy actor, this actor could then check what routees are available, and pick one and send the message forward to that actor.

pseudo code

func (*ProxyActor) Receive(context actor.Context) {
   // Fetch consul info via consul Go RPC API.
   // Pick one address from the result
   // create a PID for the above address
   pid.Tell(context.Message()) 
}

I am currently investigating what would be the best way forward to create a cluster system for GAM.
I am leaning towards using MemberList from Hashicorp, it is the same code that actually powers Consul.
That would allow GAM systems to form a cluster w/o having Consul installed.

[pavelsmejkal]

Thank you for quick reply, Proxy Actor sounds like go idea. It doesn't need to fetch consul data directly but it can be just notified from outside as well.

About MemberList if it is cover by opened API why not. But It should be possible to explicitly use already existing service catalog either consul or etcd. Since there are many subject using already such service in heterogeneous environments including me :) wink, wink