Valid to use PULL/PUSH with ROUTER socket?

[raffian]

Is PUSH/PULL valid to use with ROUTER? There's no mention of such a socket combo in the guide, I found no examples either.

I'm building a chat/im program, the server uses ROUTER/ROUTER, the clients use PUSH/PULL for sending and receiving messages from server. I also use client identities so the server can route messages to specific clients (for private chat, etc). It appears to work fine in my testing. I just want to know if this is a valid approach.

[miniway]

PUSH/PULL is valid to use with ROUTER. But I would recommend to use DEALER as a counter part of ROUTER.

By using a single DEALER at the client side, you can send and receive message to/from server. It might be easier to implement.

[raffian]

Hi Dongmin,

My client uses 2 threads; one for PUSHing messages, and another for PULLing; works great since everything on the client is async. If I switch to a single DEALER, I still need two threads on the client, and the guide says to never reuse sockets across threads. Can I break that rule if one thread always receives while the other thread always sends on the same DEALER socket? Otherwise, I don't see how this can be accomplished, but I'm open to suggestions.

[miniway]

I like a pattern using an agent. A sending thread sends messages to the agent through a pipe(INPROC socket), which ZThread.fork do a magic for you. You can use a separate receiving thread and pipe or utilize the sending thread for receiving.

A sudo code of would be

// Agent
senderPipe = ZThread.fork(ctx, sender)
receiverPipe = ZThread.fork(ctx, receiver)
sock = ctx.createSocket(ZMQ.DEALTER).connect(endpoint)

PollItem[] items = {
                    new PollItem(senderPipe, ZMQ.Poller.POLLIN),
                    new PollItem(sock, ZMQ.Poller.POLLIN)
            };
while (true) {
                int rc = ZMQ.poll(items, timeout)
                if (rc == -1)
                    break;              //  Context has been shut down

                if (items[0].isReadable())   // sender sent a message
                    sock.send(senderPipe.recv())

                if (items[1].isReadable())  // receive a message from outside
                    receiverPipe.send(sock.recv())

                // do your heartbeat 
}

Please refere chapter4 of the guide and https://github.com/imatix/zguide/blob/master/examples/Java/flcliapi.java for the agent pattern, or zyre https://github.com/zeromq/zyre/tree/master/java

[raffian]

Very nice, and I just got this code from irc, so from these examples I am in good shape, thank you
https://gist.github.com/minrk/6265022

[crystaljuicelabs]

Hi Raffian...were you able to get it running fully?