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  • RabbitMq初探——消息持久化

    消息持久化

    前言


    通过上一节,我们知道,有消息确认机制,保证了当消费者进程挂掉后,消息的不丢失。

    但是如果rabbitmq挂掉呢?它的队列和消息都会丢失的。为了保证消息在rabbitmq挂掉重启后不丢失,

    我们需要用到rabbitmq的持久化机制。

    开启持久化功能


    1. 首先保证queue的持久化,在publisher和consumer声明queue时,开启持久化功能。本章例子可以通过下面代码开启

    //函数第三个参数置为true,代表开启队列的持久化
    $channel->queue_declare('durable_queue', false, true, false, false);

    2. 其次保证message的持久化,在publisher传递消息前开启消息的持久化功能。

    $msg = new AMQPMessage($data, array('delivery_mode' => AMQPMessage::DELIVERY_MODE_PERSISTENT));

    代码


    sender.php

    <?php
    /**
     * sender.php
     * Created by PhpStorm.
     * User: wangdaxi
     * Date: 2017/10/18
     * Time: 14:26
     */
    require_once __DIR__ . '/vendor/autoload.php';
    use PhpAmqpLibConnectionAMQPStreamConnection;
    use PhpAmqpLibMessageAMQPMessage;
    
    $connection = new AMQPStreamConnection('127.0.0.1', 5672, 'guest', 'guest');
    $channel = $connection->channel();
    
    
    $channel->queue_declare('durable_queue', false, true, false, false);
    
    $data = implode(" ", array_slice($argv, 1));
    empty($data) && $data = "Hello World!";
    
    $msg = new AMQPMessage($data, array('delivery_mode' => AMQPMessage::DELIVERY_MODE_PERSISTENT));
    
    $channel->basic_publish($msg, '', 'durable_queue');
    
    echo " [x] Sent '$data'
    ";
    
    //close the channel and connection;
    $channel->close();
    $connection->close();

    receive.php

    <?php
    /**
     * receive.php
     * Created by PhpStorm.
     * User: wangdaxi
     * Date: 2017/10/18
     * Time: 14:34
     */
    require_once __DIR__ . '/vendor/autoload.php';
    use PhpAmqpLibConnectionAMQPStreamConnection;
    
    $connection = new AMQPStreamConnection('127.0.0.1', 5672, 'guest', 'guest');
    $channel = $connection->channel();
    
    $channel->queue_declare('durable_queue', false, true, false, false);
    echo ' [*] Waiting for messages. To exit press CTRL+C', "
    ";
    
    $callback = function($msg) {
        echo "[x] Received ", $msg->body, "
    ";
        sleep(substr_count($msg->body, '.'));
        echo "[x] Done
    ";
        //消息确认
        $msg->delivery_info['channel']->basic_ack($msg->delivery_info['delivery_tag']);
    };
    $channel->basic_consume('durable_queue', '', false, false, false, false, $callback);
    
    while(count($channel->callbacks)) {
        $channel->wait();
    }

    测试


    1. php sender.php 这里开启了队列,并且发送了一条消息‘hello world’

    2. sudo rabbitmqctl stop_app 关闭服务

    3. sudo rabbitmqctl start_app 开启服务

    4. php receive.php 开启消费者进程,发现能从队列【durable_queue】接收到消息。

    以上。

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  • 原文地址:https://www.cnblogs.com/hejun695/p/7692533.html
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