RabbitMq初探——消息分发
消息分发
前言
我们在用到消息队列的场景,一般是处理逻辑复杂,耗时,所以将同步改为异步处理,接入队列,下游处理耗时任务。
队列消息数量很大,且下游worker进程(消费者)处理耗时长,所以就有了任务的积压。rabbitmq提供了任务分发的机制。
流程弱化如下图:
可以接入多个消费者,rabbitmq会将消息均匀的分发给每一个消费者。
耗时任务
我们可以在consumer端用sleep()函数来模拟耗时任务,通过判断消息的点的个数,来进行相应的sleep几秒。
sender.php
require_once __DIR__ . '/vendor/autoload.php'; use PhpAmqpLib\Connection\AMQPStreamConnection; use PhpAmqpLib\Message\AMQPMessage; $connection = new AMQPStreamConnection('127.0.0.1', 5672, 'guest', 'guest'); $channel = $connection->channel(); $channel->queue_declare('hello', false, false, false, false); $data = implode(" ", array_slice($argv, 1)); empty($data) && $data = "Hello World!"; $msg = new AMQPMessage($data); $channel->basic_publish($msg, '', 'hello'); echo " [x] Sent '$data'\n"; //close the channel and connection; $channel->close(); $connection->close();
receive.php
<?php require_once __DIR__ . '/vendor/autoload.php'; use PhpAmqpLib\Connection\AMQPStreamConnection; $connection = new AMQPStreamConnection('127.0.0.1', 5672, 'guest', 'guest'); $channel = $connection->channel(); $channel->queue_declare('hello', false, false, false, false); echo ' [*] Waiting for messages. To exit press CTRL+C', "\n"; $callback = function($msg) { echo "[x] Received ", $msg->body, "\n"; sleep(substr_count($msg->body, '.')); echo "[x] Done\n"; }; $channel->basic_consume('hello', '', false, true, false, false, $callback); while(count($channel->callbacks)) { $channel->wait(); }
验证
开启两个终端作为消费者,C1,C2。
开启一个终端作为生产者,P1。
P1生产消息:
C1消费消息:
C2消费消息:
以上,是rabbitmq的 Round-robin dispatching