public function send($data)
{
$msg = new Zmsg($this->socket);
$msg->push($data);
$msg->wrap(sprintf("%.0f", microtime(1) * 1000));
$msg->send(true);
}
}
$reroutable = false;
$events = $poll->poll($readable, $writeable, 0);
if ($events > 0) {
foreach ($readable as $socket) {
$zmsg = new Zmsg($socket);
$zmsg->recv();
if ($local_capacity) {
$zmsg->wrap(array_shift($worker_queue), "");
$zmsg->set_socket($localbe)->send();
$local_capacity--;
} else {
// Route to random broker peer
printf("I: route request %s to cloud...%s", $zmsg->body(), PHP_EOL);
$zmsg->wrap($_SERVER['argv'][mt_rand(2, $_SERVER['argc'] - 1)]);
$zmsg->set_socket($cloudbe)->send();
}
}
} else {
break;
// No work, go back to backends
}
}
if ($local_capacity != $previous) {
// Broadcast new capacity
$zmsg = new Zmsg($statebe);
$zmsg->body_set($local_capacity);
// We stick our own address onto the envelope
$zmsg->wrap($self)->send();
}
}
$poll = new ZMQPoll();
$poll->add($backend, ZMQ::POLL_IN);
// Poll frontend only if we have available workers
if ($available_workers) {
$poll->add($frontend, ZMQ::POLL_IN);
}
$events = $poll->poll($read, $write);
foreach ($read as $socket) {
$zmsg = new Zmsg($socket);
$zmsg->recv();
// Handle worker activity on backend
if ($socket === $backend) {
// Use worker address for LRU routing
assert($available_workers < MAX_WORKERS);
array_push($worker_queue, $zmsg->unwrap());
$available_workers++;
// Return reply to client if it's not a READY
if ($zmsg->address() != "READY") {
$zmsg->set_socket($frontend)->send();
}
} elseif ($socket === $frontend) {
// Now get next client request, route to next worker
// REQ socket in worker needs an envelope delimiter
// Dequeue and drop the next worker address
$zmsg->wrap(array_shift($worker_queue), "");
$zmsg->set_socket($backend)->send();
$available_workers--;
}
}
// We never exit the main loop
}
/**
* Run a self test of the Zmsg class.
*
* @return boolean
* @todo See if assert returns
*/
public static function test()
{
$result = true;
$context = new ZMQContext();
$output = new ZMQSocket($context, ZMQ::SOCKET_XREQ);
$output->bind("inproc://zmsg_selftest");
$input = new ZMQSocket($context, ZMQ::SOCKET_XREP);
$input->connect("inproc://zmsg_selftest");
// Test send and receive of single-part message
$zmsgo = new Zmsg($output);
$zmsgo->body_set("Hello");
$result &= assert($zmsgo->body() == "Hello");
$zmsgo->send();
$zmsgi = new Zmsg($input);
$zmsgi->recv();
$result &= assert($zmsgi->parts() == 2);
$result &= assert($zmsgi->body() == "Hello");
echo $zmsgi;
// Test send and receive of multi-part message
$zmsgo = new Zmsg($output);
$zmsgo->body_set("Hello");
$zmsgo->wrap("address1", "");
$zmsgo->wrap("address2");
$result &= assert($zmsgo->parts() == 4);
echo $zmsgo;
$zmsgo->send();
$zmsgi = new Zmsg($input);
$zmsgi->recv();
$result &= assert($zmsgi->parts() == 5);
$zmsgi->unwrap();
$result &= assert($zmsgi->unwrap() == "address2");
$zmsgi->body_fmt("%s%s", 'W', "orld");
$result &= assert($zmsgi->body() == "World");
// Pull off address 1, check that empty part was dropped
$zmsgi->unwrap();
$result &= assert($zmsgi->parts() == 1);
// Check that message body was correctly modified
$part = $zmsgi->pop();
$result &= assert($part == "World");
$result &= assert($zmsgi->parts() == 0);
// Test load and save
$zmsg = new Zmsg();
$zmsg->body_set("Hello");
$zmsg->wrap("address1", "");
$zmsg->wrap("address2");
$result &= assert($zmsg->parts() == 4);
$fh = fopen(sys_get_temp_dir() . "/zmsgtest.zmsg", 'w');
$zmsg->save($fh);
fclose($fh);
$fh = fopen(sys_get_temp_dir() . "/zmsgtest.zmsg", 'r');
$zmsg2 = new Zmsg();
$zmsg2->load($fh);
assert($zmsg2->last() == $zmsg->last());
fclose($fh);
$result &= assert($zmsg2->parts() == 4);
echo $result ? "OK" : "FAIL", PHP_EOL;
return $result;
}
/**
* Send reply, if any, to broker and wait for next request.
*
* @param Zmsg $reply
* @return Zmsg Returns if there is a request to process
*/
public function recv($reply = null)
{
// Format and send the reply if we were provided one
assert($reply || !$this->expect_reply);
if ($reply) {
$reply->wrap($this->reply_to);
$this->send_to_broker(MDPW_REPLY, NULL, $reply);
}
$this->expect_reply = true;
$read = $write = array();
while (true) {
$poll = new ZMQPoll();
$poll->add($this->worker, ZMQ::POLL_IN);
$events = $poll->poll($read, $write, $this->heartbeat);
if ($events) {
$zmsg = new Zmsg($this->worker);
$zmsg->recv();
if ($this->verbose) {
echo "I: received message from broker:", PHP_EOL;
echo $zmsg->__toString();
}
$this->liveness = HEARTBEAT_LIVENESS;
// Don't try to handle errors, just assert noisily
assert($zmsg->parts() >= 3);
$zmsg->pop();
$header = $zmsg->pop();
assert($header == MDPW_WORKER);
$command = $zmsg->pop();
if ($command == MDPW_REQUEST) {
// We should pop and save as many addresses as there are
// up to a null part, but for now, just save one...
$this->reply_to = $zmsg->unwrap();
return $zmsg;
// We have a request to process
} else {
if ($command == MDPW_HEARTBEAT) {
// Do nothing for heartbeats
} else {
if ($command == MDPW_DISCONNECT) {
$this->connect_to_broker();
} else {
echo "E: invalid input message", PHP_EOL;
echo $zmsg->__toString();
}
}
}
} else {
if (--$this->liveness == 0) {
// poll ended on timeout, $event being false
if ($this->verbose) {
echo "W: disconnected from broker - retrying...", PHP_EOL;
}
usleep($this->reconnect * 1000);
$this->connect_to_broker();
}
}
// Send HEARTBEAT if it's time
if (microtime(true) > $this->heartbeat_at) {
$this->send_to_broker(MDPW_HEARTBEAT, NULL, NULL);
$this->heartbeat_at = microtime(true) + $this->heartbeat / 1000;
}
}
}
/**
* Process a request coming from a client
*
* @param string $sender
* @param Zmsg $msg
*/
public function client_process($sender, $msg)
{
$service_frame = $msg->pop();
$service = $this->service_require($service_frame);
// Set reply return address to client sender
$msg->wrap($sender, "");
if (substr($service_frame, 0, 4) == 'mmi.') {
$this->service_internal($service_frame, $msg);
} else {
$this->service_dispatch($service, $msg);
}
}
function main()
{
for ($client_nbr = 0; $client_nbr < NBR_CLIENTS; $client_nbr++) {
$pid = pcntl_fork();
if ($pid == 0) {
client_thread();
return;
}
}
for ($worker_nbr = 0; $worker_nbr < NBR_WORKERS; $worker_nbr++) {
$pid = pcntl_fork();
if ($pid == 0) {
worker_thread();
return;
}
}
$context = new ZMQContext();
$frontend = new ZMQSocket($context, ZMQ::SOCKET_ROUTER);
$backend = new ZMQSocket($context, ZMQ::SOCKET_ROUTER);
$frontend->bind("ipc://frontend.ipc");
$backend->bind("ipc://backend.ipc");
// Logic of LRU loop
// - Poll backend always, frontend only if 1+ worker ready
// - If worker replies, queue worker as ready and forward reply
// to client if necessary
// - If client requests, pop next worker and send request to it
// Queue of available workers
$available_workers = 0;
$worker_queue = array();
$writeable = $readable = array();
while ($client_nbr > 0) {
$poll = new ZMQPoll();
// Poll front-end only if we have available workers
if ($available_workers > 0) {
$poll->add($frontend, ZMQ::POLL_IN);
}
// Always poll for worker activity on backend
$poll->add($backend, ZMQ::POLL_IN);
$events = $poll->poll($readable, $writeable);
if ($events > 0) {
foreach ($readable as $socket) {
// Handle worker activity on backend
if ($socket === $backend) {
// Queue worker address for LRU routing
$zmsg = new Zmsg($socket);
$zmsg->recv();
assert($available_workers < NBR_WORKERS);
$available_workers++;
array_push($worker_queue, $zmsg->unwrap());
if ($zmsg->body() != "READY") {
$zmsg->set_socket($frontend)->send();
// exit after all messages relayed
$client_nbr--;
}
} else {
if ($socket === $frontend) {
$zmsg = new Zmsg($socket);
$zmsg->recv();
$zmsg->wrap(array_shift($worker_queue), "");
$zmsg->set_socket($backend)->send();
$available_workers--;
}
}
}
}
}
// Clean up our worker processes
foreach ($worker_queue as $worker) {
$zmsg = new Zmsg($backend);
$zmsg->body_set('END')->wrap($worker, "")->send();
}
sleep(1);
}
$queue->s_worker_append($identity);
} else {
if ($zmsg->address() == 'HEARTBEAT') {
$queue->s_worker_refresh($identity);
} else {
printf("E: invalid message from %s%s%s", $identity, PHP_EOL, $zmsg->__toString());
}
}
} else {
$zmsg->set_socket($frontend)->send();
$queue->s_worker_append($identity);
}
} else {
// Now get next client request, route to next worker
$identity = $queue->s_worker_dequeue();
$zmsg->wrap($identity);
$zmsg->set_socket($backend)->send();
}
}
if (microtime(true) > $heartbeat_at) {
foreach ($queue as $id => $expiry) {
$zmsg = new Zmsg($backend);
$zmsg->body_set("HEARTBEAT");
$zmsg->wrap($identity, NULL);
$zmsg->send();
}
$heartbeat_at = microtime(true) + HEARTBEAT_INTERVAL;
}
$queue->s_queue_purge();
}
}
$poll->add($localfe, ZMQ::POLL_IN);
$poll->add($cloudfe, ZMQ::POLL_IN);
$reroutable = false;
$events = $poll->poll($readable, $writeable, 0);
if ($events > 0) {
foreach ($readable as $socket) {
$zmsg = new Zmsg($socket);
$zmsg->recv();
// We'll do peer brokers first, to prevent starvation
if ($socket === $cloudfe) {
$reroutable = false;
} elseif ($socket === $localfe) {
$reroutable = true;
}
// If reroutable, send to cloud 20% of the time
// Here we'd normally use cloud status information
if ($reroutable && $_SERVER['argc'] > 2 && mt_rand(0, 4) == 0) {
$zmsg->wrap($_SERVER['argv'][mt_rand(2, $_SERVER['argc'] - 1)]);
$zmsg->set_socket($cloudbe)->send();
} else {
$zmsg->wrap(array_shift($worker_queue), "");
$zmsg->set_socket($localbe)->send();
$capacity--;
}
}
} else {
break;
// No work, go back to backends
}
}
}