protected function onPoll($events, $read, $write)
{
parent::onPoll($events, $read, $write);
if ($events > 0) {
foreach ($read as $socket) {
//handle publisher
if ($socket === $this->frontedSocket) {
$zmsg = new Zmsg($this->frontedSocket);
$zmsg->recv();
if ($this->verbose) {
echo "I: received message from publisher size: ";
echo strlen($zmsg->__toString()), PHP_EOL;
}
$zmsg->unwrap();
//time
if ($this->queueLimit > sizeof($this->queue)) {
array_unshift($this->queue, $zmsg->pop());
}
}
}
}
}
/**
* This is the main listen and process loop
*/
public function listen()
{
$read = $write = array();
// Get and process messages forever or until interrupted
while (true) {
$poll = new ZMQPoll();
$poll->add($this->socket, ZMQ::POLL_IN);
$events = $poll->poll($read, $write, HEARTBEAT_INTERVAL * ZMQ_POLL_MSEC);
// Process next input message, if any
if ($events) {
$zmsg = new Zmsg($this->socket);
$zmsg->recv();
if ($this->verbose) {
echo "I: received message:", PHP_EOL, $zmsg->__toString();
}
$sender = $zmsg->pop();
$empty = $zmsg->pop();
$header = $zmsg->pop();
if ($header == MDPC_CLIENT) {
$this->client_process($sender, $zmsg);
} else {
if ($header = MDPW_WORKER) {
$this->worker_process($sender, $zmsg);
} else {
echo "E: invalid message", PHP_EOL, $zmsg->__toString();
}
}
}
// Disconnect and delete any expired workers
// Send heartbeats to idle workers if needed
if (microtime(true) > $this->heartbeat_at) {
$this->purge_workers();
foreach ($this->workers as $worker) {
$this->worker_send($worker, MDPW_HEARTBEAT, NULL, NULL);
}
$this->heartbeat_at = microtime(true) + HEARTBEAT_INTERVAL / 1000;
}
}
}
/**
* Start listen for messages in loop
* @throws \Exception
*/
public function listen()
{
if (!$this->listener) {
throw new \Exception("Empty listener");
}
$this->isListen = true;
while ($this->isListen) {
$zmsg = new Zmsg($this->socket);
$zmsg->recv();
if ($this->verbose) {
echo "I: received message from broker:", PHP_EOL;
echo $zmsg->__toString(), PHP_EOL;
}
$time = $zmsg->unwrap();
if (!$this->normalDelay) {
$this->normalDelay = microtime(true) * 1000 - (double) $time;
}
$delayTime = microtime(true) * 1000 - (double) $time;
if ($this->misser && $delayTime > $this->normalDelay + $this->maxAllowedDelay) {
call_user_func($this->misser, $zmsg->pop(), $time, $delayTime);
}
call_user_func($this->listener, $zmsg->pop(), $time);
}
}
/**
* 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) + $this->heartbeat / 1000;
}
}
}
if ($cycles > 3 && rand(0, 5) == 0) {
printf("I: (%s) simulating a crash%s", $identity, PHP_EOL);
break;
} elseif ($cycles > 3 && rand(0, 5) == 0) {
printf("I: (%s) simulating CPU overload%s", $identity, PHP_EOL);
sleep(5);
}
printf("I: (%s) normal reply - %s%s", $identity, $zmsg->body(), PHP_EOL);
$zmsg->send();
$liveness = HEARTBEAT_LIVENESS;
sleep(1);
// Do some heavy work
} elseif ($zmsg->parts() == 1 && $zmsg->body() == 'HEARTBEAT') {
$liveness = HEARTBEAT_LIVENESS;
} else {
printf("E: (%s) invalid message%s%s", $identity, PHP_EOL, $zmsg->__toString());
}
$interval = INTERVAL_INIT;
} elseif (--$liveness == 0) {
printf("W: (%s) heartbeat failure, can't reach queue%s", $identity, PHP_EOL);
printf("W: (%s) reconnecting in %d msec...%s", $identity, $interval, PHP_EOL);
usleep($interval * 1000);
if ($interval < INTERVAL_MAX) {
$interval *= 2;
}
list($worker, $identity) = s_worker_socket($context);
$liveness = HEARTBEAT_LIVENESS;
}
// Send heartbeat to queue if it's time
if (microtime(true) > $heartbeat_at) {
$heartbeat_at = microtime(true) + HEARTBEAT_INTERVAL;
/**
* Process message sent to us by a worker
*
* @param string $sender
* @param Zmsg $msg
*/
public function worker_process($sender, $msg)
{
$command = $msg->pop();
$worker_ready = isset($this->workers[$sender]);
$worker = $this->worker_require($sender);
if ($command == MDPW_READY) {
if ($worker_ready) {
$this->worker_delete($worker, true);
// Not first command in session
} else {
if (strlen($sender) >= 4 && substr($sender, 0, 4) == 'mmi.') {
$this->worker_delete($worker, true);
} else {
// Attach worker to service and mark as idle
$service_frame = $msg->pop();
$worker->service = $this->service_require($service_frame);
$worker->service->workers++;
$this->worker_waiting($worker);
}
}
} else {
if ($command == MDPW_REPLY) {
if ($worker_ready) {
// Remove & save client return envelope and insert the
// protocol header and service name, then rewrap envelope.
$client = $msg->unwrap();
$msg->push($worker->service->name);
$msg->push(MDPC_CLIENT);
$msg->wrap($client, "");
$msg->set_socket($this->socket)->send();
$this->worker_waiting($worker);
} else {
$this->worker_delete($worker, true);
}
} else {
if ($command == MDPW_HEARTBEAT) {
if ($worker_ready) {
$worker->expiry = microtime(true) + HEARTBEAT_EXPIRY / 1000;
} else {
$this->worker_delete($worker, true);
}
} else {
if ($command == MDPW_DISCONNECT) {
$this->worker_delete($worker, true);
} else {
echo "E: invalid input message", PHP_EOL, $msg->__toString();
}
}
}
}
}
/**
* Returns the reply message or NULL if there was no reply. Does not
* attempt to recover from a broker failure, this is not possible
* without storing all unanswered requests and resending them all...
*
*/
public function recv()
{
$read = $write = array();
// Poll socket for a reply, with timeout
$poll = new ZMQPoll();
$poll->add($this->client, ZMQ::POLL_IN);
$events = $poll->poll($read, $write, $this->timeout);
// If we got a reply, process it
if ($events) {
$msg = new Zmsg($this->client);
$msg->recv();
if ($this->verbose) {
echo "I: received reply:", $msg->__toString(), PHP_EOL;
}
// Don't try to handle errors, just assert noisily
assert($msg->parts() >= 4);
$msg->pop();
// empty
$header = $msg->pop();
assert($header == MDPC_CLIENT);
$reply_service = $msg->pop();
return $msg;
// Success
} else {
echo "W: permanent error, abandoning request", PHP_EOL;
return;
// Give up
}
}
protected function process($sender, Zmsg $zmsg)
{
$command = $zmsg->pop();
$hasWorker = $this->hasWorker($sender);
switch ($command) {
case Commands::W_READY:
if (!$hasWorker) {
$this->addWorker($sender);
} else {
echo "E: Ready from ready worker `{$sender}` - disconnect ", PHP_EOL;
$this->deleteWorker($this->workers[$sender], true);
}
break;
case Commands::W_HEARTBEAT:
if ($hasWorker) {
$this->live($this->workers[$sender]);
} else {
echo "E: Heartbeat from not ready worker `{$sender}` - disconnect ", PHP_EOL;
$this->send($sender, Commands::W_RESPONSE);
}
break;
case Commands::W_RESPONSE:
if ($hasWorker) {
if ($this->responder) {
$response = $zmsg->pop();
call_user_func($this->responder, $response);
}
$this->free($this->workers[$sender]);
} else {
echo "E: Response from not ready worker `{$sender}` - disconnect ", PHP_EOL;
$this->send($sender, Commands::W_RESPONSE);
}
break;
default:
echo "E: Unsupported command `{$command}`.", PHP_EOL;
echo $zmsg->__toString(), PHP_EOL, PHP_EOL;
}
}
/**
* Send request to broker and get reply by hook or crook
* Takes ownership of request message and destroys it when sent.
* Returns the reply message or NULL if there was no reply.
*
* @param string $service
* @param Zmsg $request
* @param string $client
* @return Zmsg
*/
public function send($service, Zmsg $request)
{
// Prefix request with protocol frames
// Frame 1: "MDPCxy" (six bytes, MDP/Client
// Frame 2: Service name (printable string)
$request->push($service);
$request->push(MDPC_CLIENT);
if ($this->verbose) {
printf("I: send request to '%s' service:", $service);
echo $request->__toString();
}
$retries_left = $this->retries;
$read = $write = array();
while ($retries_left) {
$request->set_socket($this->client)->send();
// Poll socket for a reply, with timeout
$poll = new ZMQPoll();
$poll->add($this->client, ZMQ::POLL_IN);
$events = $poll->poll($read, $write, $this->timeout);
// If we got a reply, process it
if ($events) {
$request->recv();
if ($this->verbose) {
echo "I: received reply:", $request->__toString(), PHP_EOL;
}
// Don't try to handle errors, just assert noisily
assert($request->parts() >= 3);
$header = $request->pop();
assert($header == MDPC_CLIENT);
$reply_service = $request->pop();
assert($reply_service == $service);
return $request;
// Success
} elseif ($retries_left--) {
if ($this->verbose) {
echo "W: no reply, reconnecting...", PHP_EOL;
}
// Reconnect, and resend message
$this->connect_to_broker();
$request->send();
} else {
echo "W: permanent error, abandoning request", PHP_EOL;
break;
// Give up
}
}
}
foreach ($read as $socket) {
$zmsg = new Zmsg($socket);
$zmsg->recv();
// Handle worker activity on backend
if ($socket === $backend) {
$identity = $zmsg->unwrap();
// Return reply to client if it's not a control message
if ($zmsg->parts() == 1) {
if ($zmsg->address() == "READY") {
$queue->s_worker_delete($identity);
$queue->s_worker_append($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) {
/**
* Send request to broker
* Takes ownership of request message and destroys it when sent.
*
* @param string $service
* @param Zmsg $request
*/
public function send($service, Zmsg $request)
{
// Prefix request with protocol frames
// Frame 0: empty (REQ emulation)
// Frame 1: "MDPCxy" (six bytes, MDP/Client x.y)
// Frame 2: Service name (printable string)
$request->push($service);
$request->push(MDPC_CLIENT);
$request->push("");
if ($this->verbose) {
printf("I: send request to '%s' service: %s", $service, PHP_EOL);
echo $request->__toString();
}
$request->set_socket($this->client)->send();
}
protected function onPoll($events, $read, $write)
{
$events = $this->poll->poll($read, $write, $this->heartbeatDelay);
$sendHeartBeat = true;
if ($events) {
$zmsg = new Zmsg($this->socket);
$zmsg->recv();
if ($this->verbose) {
echo "I: received message from broker:", PHP_EOL;
echo $zmsg->__toString(), PHP_EOL;
}
$this->heartbeatTriesLeft = $this->heartbeatMaxFails;
$zmsg->pop();
$header = $zmsg->pop();
assert($header == Commands::W_WORKER);
$command = $zmsg->pop();
if ($command == Commands::W_HEARTBEAT) {
} elseif ($command == Commands::W_REQUEST) {
//@todo: get address
$result = call_user_func($this->executor, $zmsg->pop());
$this->send($result);
//resp = HB
$sendHeartBeat = false;
} elseif ($command == Commands::W_RESPONSE) {
$this->connect();
} else {
echo "I: Unsupported command `{$command}`.", PHP_EOL;
echo $zmsg->__toString(), PHP_EOL, PHP_EOL;
}
} elseif (--$this->heartbeatTriesLeft == 0) {
if ($this->verbose) {
echo "I: disconnected from broker - retrying... ", PHP_EOL;
}
usleep($this->reconnectDelay * 1000);
$this->connect();
}
$this->sendHeartbeat($sendHeartBeat);
}
