延迟任务应用场景
场景一:物联网系统经常会遇到向终端下发命令,如果命令一段时间没有应答,就需要设置成超时。
场景二:订单下单之后30分钟后,如果用户没有付钱,则系统自动取消订单。
场景三:过1分钟给新注册会员的用户,发送注册邮件等。
php 使用rabbitmq-delayed-message-exchange插件实现延迟功能
1.安装
下载后解压,并将其拷贝至(使用Linux Debian/RPM部署)rabbitmq服务器目录:/usr/local/rabbitmq/plugins
中( windows安装目录
abbitmq_server-versionplugins
).
2.启用插件
使用命令rabbitmq-plugins enable rabbitmq_delayed_message_exchang
启用插件
rabbitmq-plugins enable rabbitmq_delayed_message_exchang
输出如下:
The following plugins have been enabled:
rabbitmq_delayed_message_exchange
通过rabbitmq-plugins list
查看已安装列表,如下:
...
[ ] rabbitmq_delayed_message_exchange 20171215-3.6.x
...
3.机制解释
安装插件后会生成新的Exchange类型x-delayed-message
,该类型消息支持延迟投递机制,接收到消息后并未立即将消息投递至目标队列中,而是存储在mnesia
(一个分布式数据系统)表中,检测消息延迟时间,如达到可投递时间时并将其通过x-delayed-type
类型标记的交换机类型投递至目标队列。
4.php实现过程
消费者 delay_consumer2.php:
<?php //header('Content-Type:text/html;charset=utf8;'); $params = array( 'exchangeName' => 'delayed_exchange_test', 'queueName' => 'delayed_queue_test', 'routeKey' => 'delayed_route_test', ); $connectConfig = array( 'host' => 'localhost', 'port' => 5672, 'login' => 'guest', 'password' => 'guest', 'vhost' => '/' ); //var_dump(extension_loaded('amqp')); //exit(); try { $conn = new AMQPConnection($connectConfig); $conn->connect(); if (!$conn->isConnected()) { //die('Conexiune esuata'); //TODO 记录日志 echo 'rabbit-mq 连接错误:', json_encode($connectConfig); exit(); } $channel = new AMQPChannel($conn); if (!$channel->isConnected()) { // die('Connection through channel failed'); //TODO 记录日志 echo 'rabbit-mq Connection through channel failed:', json_encode($connectConfig); exit(); } $exchange = new AMQPExchange($channel); //$exchange->setFlags(AMQP_DURABLE);//声明一个已存在的交换器的,如果不存在将抛出异常,这个一般用在consume端 $exchange->setName($params['exchangeName']); $exchange->setType('x-delayed-message'); //x-delayed-message类型 /*RabbitMQ常用的Exchange Type有三种:fanout、direct、topic。 fanout:把所有发送到该Exchange的消息投递到所有与它绑定的队列中。 direct:把消息投递到那些binding key与routing key完全匹配的队列中。 topic:将消息路由到binding key与routing key模式匹配的队列中。*/ $exchange->setArgument('x-delayed-type','direct'); $exchange->declareExchange(); //$channel->startTransaction(); $queue = new AMQPQueue($channel); $queue->setName($params['queueName']); $queue->setFlags(AMQP_DURABLE); $queue->declareQueue(); //绑定 $queue->bind($params['exchangeName'], $params['routeKey']); } catch(Exception $e) { echo $e->getMessage(); exit(); } function callback(AMQPEnvelope $message) { global $queue; if ($message) { $body = $message->getBody(); echo '接收时间:'.date("Y-m-d H:i:s", time()). PHP_EOL; echo '接收内容:'.$body . PHP_EOL; //为了防止接收端在处理消息时down掉,只有在消息处理完成后才发送ack消息 $queue->ack($message->getDeliveryTag()); } else { echo 'no message' . PHP_EOL; } } //$queue->consume('callback'); 第一种消费方式,但是会阻塞,程序一直会卡在此处 //第二种消费方式,非阻塞 /*$start = time(); while(true) { $message = $queue->get(); if(!empty($message)) { echo $message->getBody(); $queue->ack($message->getDeliveryTag()); //应答,代表该消息已经消费 $end = time(); echo '<br>' . ($end - $start); exit(); } else { //echo 'message not found' . PHP_EOL; } }*/ //注意:这里需要注意的是这个方法:$queue->consume,queue对象有两个方法可用于取消息:consume和get。前者是阻塞的,无消息时会被挂起,适合循环中使用;后者则是非阻塞的,取消息时有则取,无则返回false。 //就是说用了consume之后,会同步阻塞,该程序常驻内存,不能用nginx,apache调用。 $action = '2'; if($action == '1'){ $queue->consume('callback'); //第一种消费方式,但是会阻塞,程序一直会卡在此处 }else{ //第二种消费方式,非阻塞 $start = time(); while(true) { $message = $queue->get(); if(!empty($message)) { echo '接收时间:'.date("Y-m-d H:i:s", time()). PHP_EOL; echo '接收内容:'.$message->getBody().PHP_EOL; $queue->ack($message->getDeliveryTag()); //应答,代表该消息已经消费 $end = time(); echo '运行时间:'.($end - $start).'秒'.PHP_EOL; //exit(); } else { //echo 'message not found' . PHP_EOL; } } }
生产者delay_publisher2.php:
<?php //header('Content-Type:text/html;charset=utf-8;'); $params = array( 'exchangeName' => 'delayed_exchange_test', 'queueName' => 'delayed_queue_test', 'routeKey' => 'delayed_route_test', ); $connectConfig = array( 'host' => 'localhost', 'port' => 5672, 'login' => 'guest', 'password' => 'guest', 'vhost' => '/' ); //var_dump(extension_loaded('amqp')); 判断是否加载amqp扩展 //exit(); try { $conn = new AMQPConnection($connectConfig); $conn->connect(); if (!$conn->isConnected()) { //die('Conexiune esuata'); //TODO 记录日志 echo 'rabbit-mq 连接错误:', json_encode($connectConfig); exit(); } $channel = new AMQPChannel($conn); if (!$channel->isConnected()) { // die('Connection through channel failed'); //TODO 记录日志 echo 'rabbit-mq Connection through channel failed:', json_encode($connectConfig); exit(); } $exchange = new AMQPExchange($channel); $exchange->setName($params['exchangeName']); $exchange->setType('x-delayed-message'); //x-delayed-message类型 /*RabbitMQ常用的Exchange Type有三种:fanout、direct、topic。 fanout:把所有发送到该Exchange的消息投递到所有与它绑定的队列中。 direct:把消息投递到那些binding key与routing key完全匹配的队列中。 topic:将消息路由到binding key与routing key模式匹配的队列中。*/ $exchange->setArgument('x-delayed-type','direct'); $exchange->declareExchange(); //$channel->startTransaction(); //RabbitMQ不容许声明2个相同名称、配置不同的Queue,否则报错 $queue = new AMQPQueue($channel); $queue->setName($params['queueName']); $queue->setFlags(AMQP_DURABLE); $queue->declareQueue(); //绑定队列和交换机 $queue->bind($params['exchangeName'], $params['routeKey']); //$channel->commitTransaction(); } catch(Exception $e) { } for($i=5;$i>0;$i--){ //生成消息 echo '发送时间:'.date("Y-m-d H:i:s", time()).PHP_EOL; echo 'i='.$i.',延迟'.$i.'秒'.PHP_EOL; $message = json_encode(['order_id'=>time(),'i'=>$i]); $exchange->publish($message, $params['routeKey'], AMQP_NOPARAM, ['headers'=>['x-delay'=> 1000*$i]]); sleep(2); } $conn->disconnect();
对于代码来讲,首先对于消费者核心代码
$exchange->setType('x-delayed-message'); //x-delayed-message类型 $exchange->setArgument('x-delayed-type','direct');
生产者核心代码
$exchange = new AMQPExchange($channel); $exchange->setName($params['exchangeName']); $exchange->setType('x-delayed-message'); //x-delayed-message类型 $exchange->setArgument('x-delayed-type','direct'); $exchange->declareExchange();
使用方法:先运行delay_consumer1.php,再运行delay_publisher1.php
运行效果: