public void run() {
Socket worker = ctx.createSocket(ZMQ.DEALER);
worker.connect("inproc://backend");
while (!Thread.currentThread().isInterrupted()) {
// The DEALER socket gives us the address envelope and message
ZMsg msg = ZMsg.recvMsg(worker);
ZFrame address = msg.pop();
ZFrame content = msg.pop();
assert (content != null);
msg.destroy();
// Send 0..4 replies back
int replies = rand.nextInt(5);
for (int reply = 0; reply < replies; reply++) {
// Sleep for some fraction of a second
try {
Thread.sleep(rand.nextInt(1000) + 1);
} catch (InterruptedException e) {
}
address.send(worker, ZFrame.REUSE + ZFrame.MORE);
content.send(worker, ZFrame.REUSE);
}
address.destroy();
content.destroy();
}
ctx.destroy();
}
public static void main(String[] args) {
if (args.length < 1) {
System.out.printf("I: syntax: flserver2 <endpoint>\n");
System.exit(0);
}
ZContext ctx = new ZContext();
Socket server = ctx.createSocket(ZMQ.REP);
server.bind(args[0]);
System.out.printf("I: echo service is ready at %s\n", args[0]);
while (true) {
ZMsg request = ZMsg.recvMsg(server);
if (request == null) break; // Interrupted
// Fail nastily if run against wrong client
assert (request.size() == 2);
ZFrame identity = request.pop();
request.destroy();
ZMsg reply = new ZMsg();
reply.add(identity);
reply.add("OK");
reply.send(server);
}
if (Thread.currentThread().isInterrupted()) System.out.printf("W: interrupted\n");
ctx.destroy();
}
public void run() {
ZContext ctx = new ZContext();
Socket client = ctx.createSocket(ZMQ.DEALER);
// Set random identity to make tracing easier
String identity = String.format("%04X-%04X", rand.nextInt(), rand.nextInt());
client.setIdentity(identity.getBytes());
client.connect("tcp://localhost:5570");
PollItem[] items = new PollItem[] {new PollItem(client, Poller.POLLIN)};
int requestNbr = 0;
while (!Thread.currentThread().isInterrupted()) {
// Tick once per second, pulling in arriving messages
for (int centitick = 0; centitick < 100; centitick++) {
ZMQ.poll(items, 10);
if (items[0].isReadable()) {
ZMsg msg = ZMsg.recvMsg(client);
msg.getLast().print(identity);
msg.destroy();
}
}
client.send(String.format("request #%d", ++requestNbr), 0);
}
ctx.destroy();
}
public static void main(String[] args) throws Exception {
boolean verbose = true; // (args.length > 0 && args[0].equals("-v"));
mdcliapi session = new mdcliapi("tcp://localhost:5555", verbose);
// 1. Send 'echo' request to Titanic
ZMsg request = new ZMsg();
request.add("echo");
request.add("Hello world");
ZMsg reply = serviceCall(session, "titanic.request", request);
ZFrame uuid = null;
if (reply != null) {
uuid = reply.pop();
reply.destroy();
uuid.print("I: request UUID ");
}
// 2. Wait until we get a reply
while (!Thread.currentThread().isInterrupted()) {
Thread.sleep(100);
request = new ZMsg();
request.add(uuid.duplicate());
reply = serviceCall(session, "titanic.reply", request);
if (reply != null) {
String replyString = reply.getLast().toString();
System.out.printf("Reply: %s\n", replyString);
reply.destroy();
// 3. Close request
request = new ZMsg();
request.add(uuid.duplicate());
reply = serviceCall(session, "titanic.close", request);
reply.destroy();
break;
} else {
System.out.println("I: no reply yet, trying again...");
Thread.sleep(5000); // Try again in 5 seconds
}
}
uuid.destroy();
session.destroy();
}
// .split get method
// Look up value in distributed hash table. Sends [GET][key] to the agent and
// waits for a value response. If there is no value available, will eventually
// return NULL:
public String get(String key) {
ZMsg msg = new ZMsg();
msg.add("GET");
msg.add(key);
msg.send(pipe);
ZMsg reply = ZMsg.recvMsg(pipe);
if (reply != null) {
String value = reply.popString();
reply.destroy();
return value;
}
return null;
}
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();
}
static ZMsg serviceCall(mdcliapi session, String service, ZMsg request) {
ZMsg reply = session.send(service, request);
if (reply != null) {
ZFrame status = reply.pop();
if (status.streq("200")) {
status.destroy();
return reply;
} else if (status.streq("400")) {
System.out.println("E: client fatal error, aborting");
} else if (status.streq("500")) {
System.out.println("E: server fatal error, aborting");
}
reply.destroy();
}
return null; // Didn't succeed; don't care why not
}
public static void main(String[] args) throws InterruptedException {
boolean verbose = (args.length > 0 && "-v".equals(args[0]));
verbose = true;
MdClientApi clientSession = new MdClientApi("tcp://localhost:5500", verbose);
int count;
for (count = 0; count < 100; count++) {
ZMsg request = new ZMsg();
request.addString("Hello world");
clientSession.send("echo", request);
}
for (count = 0; count < 100; count++) {
ZMsg reply = clientSession.recv();
if (reply != null) reply.destroy();
else break; // Interrupt or failure
}
System.out.printf("%d requests/replies processed\n", count);
clientSession.destroy();
}
// .split handling a control message
// Here we handle the different control messages from the frontend;
// SUBTREE, CONNECT, SET, and GET:
private boolean controlMessage() {
ZMsg msg = ZMsg.recvMsg(pipe);
String command = msg.popString();
if (command == null) return false; // Interrupted
if (command.equals("SUBTREE")) {
subtree = msg.popString();
} else if (command.equals("CONNECT")) {
String address = msg.popString();
String service = msg.popString();
if (nbrServers < SERVER_MAX) {
server[nbrServers++] = new Server(ctx, address, Integer.parseInt(service), subtree);
// We broadcast updates to all known servers
publisher.connect(String.format("%s:%d", address, Integer.parseInt(service) + 2));
} else System.out.printf("E: too many servers (max. %d)\n", SERVER_MAX);
} else
// .split set and get commands
// When we set a property, we push the new key-value pair onto
// all our connected servers:
if (command.equals("SET")) {
String key = msg.popString();
String value = msg.popString();
String ttl = msg.popString();
kvmap.put(key, value);
// Send key-value pair on to server
kvmsg kvmsg = new kvmsg(0);
kvmsg.setKey(key);
kvmsg.setUUID();
kvmsg.fmtBody("%s", value);
kvmsg.setProp("ttl", ttl);
kvmsg.send(publisher);
kvmsg.destroy();
} else if (command.equals("GET")) {
String key = msg.popString();
String value = kvmap.get(key);
if (value != null) pipe.send(value);
else pipe.send("");
}
msg.destroy();
return true;
}
@Override
public int handle(ZLoop loop, PollItem item, Object arg_) {
LBBroker arg = (LBBroker) arg_;
ZMsg msg = ZMsg.recvMsg(arg.backend);
if (msg != null) {
ZFrame address = msg.unwrap();
// Queue worker address for load-balancing
arg.workers.add(address);
// Enable reader on frontend if we went from 0 to 1 workers
if (arg.workers.size() == 1) {
PollItem newItem = new PollItem(arg.frontend, ZMQ.Poller.POLLIN);
loop.addPoller(newItem, frontendHandler, arg);
}
// Forward message to client if it's not a READY
ZFrame frame = msg.getFirst();
if (Arrays.equals(frame.getData(), WORKER_READY)) msg.destroy();
else msg.send(arg.frontend);
}
return 0;
}
// The main task is an LRU queue with heartbeating on workers so we can
// detect crashed or blocked worker tasks:
public static void main(final String[] args) {
final ZContext ctx = new ZContext();
final Socket frontend = ctx.createSocket(ZMQ.ROUTER);
final Socket backend = ctx.createSocket(ZMQ.ROUTER);
frontend.bind("tcp://*:5555"); // For clients
backend.bind("tcp://*:5556"); // For workers
// List of available workers
final ArrayList<Worker> workers = new ArrayList<Worker>();
// Send out heartbeats at regular intervals
long heartbeat_at = System.currentTimeMillis() + HEARTBEAT_INTERVAL;
while (true) {
final PollItem items[] = {
new PollItem(backend, ZMQ.Poller.POLLIN), new PollItem(frontend, ZMQ.Poller.POLLIN)
};
// Poll frontend only if we have available workers
final int rc = ZMQ.poll(items, workers.size() > 0 ? 2 : 1, HEARTBEAT_INTERVAL);
if (rc == -1) {
break; // Interrupted
}
// Handle worker activity on backend
if (items[0].isReadable()) {
// Use worker address for LRU routing
final ZMsg msg = ZMsg.recvMsg(backend);
if (msg == null) {
break; // Interrupted
}
// Any sign of life from worker means it's ready
final ZFrame address = msg.unwrap();
final Worker worker = new Worker(address);
worker.ready(workers);
// Validate control message, or return reply to client
if (msg.size() == 1) {
final ZFrame frame = msg.getFirst();
final String data = new String(frame.getData());
if (!data.equals(PPP_READY) && !data.equals(PPP_HEARTBEAT)) {
System.out.println("E: invalid message from worker");
msg.dump(System.out);
}
msg.destroy();
} else {
msg.send(frontend);
}
}
if (items[1].isReadable()) {
// Now get next client request, route to next worker
final ZMsg msg = ZMsg.recvMsg(frontend);
if (msg == null) {
break; // Interrupted
}
msg.push(Worker.next(workers));
msg.send(backend);
}
// We handle heartbeating after any socket activity. First we send
// heartbeats to any idle workers if it's time. Then we purge any
// dead workers:
if (System.currentTimeMillis() >= heartbeat_at) {
for (final Worker worker : workers) {
worker.address.send(backend, ZFrame.REUSE + ZFrame.MORE);
final ZFrame frame = new ZFrame(PPP_HEARTBEAT);
frame.send(backend, 0);
}
heartbeat_at = System.currentTimeMillis() + HEARTBEAT_INTERVAL;
}
Worker.purge(workers);
}
// When we're done, clean up properly
while (workers.size() > 0) {
final Worker worker = workers.remove(0);
}
workers.clear();
ctx.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();
}
// Takes ownership of supplied frame
public void setContent(ZMsg frame) {
if (content != null) content.destroy();
content = frame;
}