@Override public int handle(ZLoop loop, PollItem item, Object arg_) { LBBroker arg = (LBBroker) arg_; ZMsg msg = ZMsg.recvMsg(arg.frontend); if (msg != null) { msg.wrap(arg.workers.poll()); msg.send(arg.backend); // Cancel reader on frontend if we went from 1 to 0 workers if (arg.workers.size() == 0) { loop.removePoller(new PollItem(arg.frontend, 0)); } } return 0; }
public void run() { LOGGER.info("DynamicUtil run()"); String result = "result from dynamic worker"; // getParsedPage(); ZMsg msg = new ZMsg(); msg.addFirst(result); // msg.addFirst(new byte[0]); msg.wrap(sendTo); msg.addFirst(MDP.W_REPLY.newFrame()); msg.addFirst(MDP.DYNAMIC_WORKER.newFrame()); msg.addFirst(new byte[0]); // 这就是dealer与req的不同之处,req在此处会自动加入一个空帧 LOGGER.info("I:sending reply to broker\n" + msg.toString()); System.out.println("I:sending reply to broker\n" + msg.toString()); // msg.dump(log.out()); msg.send(worker); msg.destroy(); }
// The main task begins by setting-up all its sockets. The local frontend // talks to clients, and our local backend talks to workers. The cloud // frontend talks to peer brokers as if they were clients, and the cloud // backend talks to peer brokers as if they were workers. The state // backend publishes regular state messages, and the state frontend // subscribes to all state backends to collect these messages. Finally, // we use a PULL monitor socket to collect printable messages from tasks: public static void main(String[] argv) { // First argument is this broker's name // Other arguments are our peers' names // if (argv.length < 1) { System.out.println("syntax: peering3 me {you}"); System.exit(-1); } self = argv[0]; System.out.printf("I: preparing broker at %s\n", self); Random rand = new Random(System.nanoTime()); ZContext ctx = new ZContext(); // Prepare local frontend and backend Socket localfe = ctx.createSocket(ZMQ.ROUTER); localfe.bind(String.format("ipc://%s-localfe.ipc", self)); Socket localbe = ctx.createSocket(ZMQ.ROUTER); localbe.bind(String.format("ipc://%s-localbe.ipc", self)); // Bind cloud frontend to endpoint Socket cloudfe = ctx.createSocket(ZMQ.ROUTER); cloudfe.setIdentity(self.getBytes()); cloudfe.bind(String.format("ipc://%s-cloud.ipc", self)); // Connect cloud backend to all peers Socket cloudbe = ctx.createSocket(ZMQ.ROUTER); cloudbe.setIdentity(self.getBytes()); int argn; for (argn = 1; argn < argv.length; argn++) { String peer = argv[argn]; System.out.printf("I: connecting to cloud forintend at '%s'\n", peer); cloudbe.connect(String.format("ipc://%s-cloud.ipc", peer)); } // Bind state backend to endpoint Socket statebe = ctx.createSocket(ZMQ.PUB); statebe.bind(String.format("ipc://%s-state.ipc", self)); // Connect statefe to all peers Socket statefe = ctx.createSocket(ZMQ.SUB); statefe.subscribe("".getBytes()); for (argn = 1; argn < argv.length; argn++) { String peer = argv[argn]; System.out.printf("I: connecting to state backend at '%s'\n", peer); statefe.connect(String.format("ipc://%s-state.ipc", peer)); } // Prepare monitor socket Socket monitor = ctx.createSocket(ZMQ.PULL); monitor.bind(String.format("ipc://%s-monitor.ipc", self)); // Start local workers int worker_nbr; for (worker_nbr = 0; worker_nbr < NBR_WORKERS; worker_nbr++) new worker_task().start(); // Start local clients int client_nbr; for (client_nbr = 0; client_nbr < NBR_CLIENTS; client_nbr++) new client_task().start(); // Queue of available workers int localCapacity = 0; int cloudCapacity = 0; ArrayList<ZFrame> workers = new ArrayList<ZFrame>(); // The main loop has two parts. First we poll workers and our two service // sockets (statefe and monitor), in any case. If we have no ready workers, // there's no point in looking at incoming requests. These can remain on // their internal 0MQ queues: while (true) { // First, route any waiting replies from workers PollItem primary[] = { new PollItem(localbe, Poller.POLLIN), new PollItem(cloudbe, Poller.POLLIN), new PollItem(statefe, Poller.POLLIN), new PollItem(monitor, Poller.POLLIN) }; // If we have no workers anyhow, wait indefinitely int rc = ZMQ.poll(primary, localCapacity > 0 ? 1000 : -1); if (rc == -1) break; // Interrupted // Track if capacity changes during this iteration int previous = localCapacity; // Handle reply from local worker ZMsg msg = null; if (primary[0].isReadable()) { msg = ZMsg.recvMsg(localbe); if (msg == null) break; // Interrupted ZFrame address = msg.unwrap(); workers.add(address); localCapacity++; // If it's READY, don't route the message any further ZFrame frame = msg.getFirst(); if (new String(frame.getData()).equals(WORKER_READY)) { msg.destroy(); msg = null; } } // Or handle reply from peer broker else if (primary[1].isReadable()) { msg = ZMsg.recvMsg(cloudbe); if (msg == null) break; // Interrupted // We don't use peer broker address for anything ZFrame address = msg.unwrap(); address.destroy(); } // Route reply to cloud if it's addressed to a broker for (argn = 1; msg != null && argn < argv.length; argn++) { byte[] data = msg.getFirst().getData(); if (argv[argn].equals(new String(data))) { msg.send(cloudfe); msg = null; } } // Route reply to client if we still need to if (msg != null) msg.send(localfe); // If we have input messages on our statefe or monitor sockets we // can process these immediately: if (primary[2].isReadable()) { String peer = statefe.recvStr(); String status = statefe.recvStr(); cloudCapacity = Integer.parseInt(status); } if (primary[3].isReadable()) { String status = monitor.recvStr(); System.out.println(status); } // Now we route as many client requests as we have worker capacity // for. We may reroute requests from our local frontend, but not from // // the cloud frontend. We reroute randomly now, just to test things // out. In the next version we'll do this properly by calculating // cloud capacity:// while (localCapacity + cloudCapacity > 0) { PollItem secondary[] = { new PollItem(localfe, Poller.POLLIN), new PollItem(cloudfe, Poller.POLLIN) }; if (localCapacity > 0) rc = ZMQ.poll(secondary, 2, 0); else rc = ZMQ.poll(secondary, 1, 0); assert (rc >= 0); if (secondary[0].isReadable()) { msg = ZMsg.recvMsg(localfe); } else if (secondary[1].isReadable()) { msg = ZMsg.recvMsg(cloudfe); } else break; // No work, go back to backends if (localCapacity > 0) { ZFrame frame = workers.remove(0); msg.wrap(frame); msg.send(localbe); localCapacity--; } else { // Route to random broker peer int random_peer = rand.nextInt(argv.length - 1) + 1; msg.push(argv[random_peer]); msg.send(cloudbe); } } // We broadcast capacity messages to other peers; to reduce chatter // we do this only if our capacity changed. if (localCapacity != previous) { // We stick our own address onto the envelope statebe.sendMore(self); // Broadcast new capacity statebe.send(String.format("%d", localCapacity), 0); } } // When we're done, clean up properly while (workers.size() > 0) { ZFrame frame = workers.remove(0); frame.destroy(); } ctx.destroy(); }