ActiveMQ笔记(7)：如何清理无效的延时消息？

2023-09-14 15:34| 来源: 网络整理| 查看: 265

ActiveMQ的延时消息是一个让人又爱又恨的功能，具体使用可参考上篇ActiveMQ笔记(6)：消息延时投递，在很多需要消息延时投递的业务场景十分有用，但是也有一个缺陷，在一些大访问量的场景，如果瞬间向MQ发送海量的延时消息，超过MQ的调度能力，就会造成很多消息到了该投递的时刻，却没有投递出去，形成积压，一直停留在ActiveMQ web控制台的Scheduled面板中。

下面的代码演示了，如何清理activemq中的延时消息（包括：全部清空及清空指定时间段的延时消息），这也是目前唯一可行的办法。

为了演示方便，先封装一个小工具类：

package cn.mwee.utils.mq; import cn.mwee.utils.list.ListUtil; import cn.mwee.utils.log4j2.MwLogger; import org.apache.commons.lang.StringUtils; import org.slf4j.Logger; import org.springframework.jms.core.JmsTemplate; import org.springframework.jms.core.MessagePostProcessor; import javax.jms.ConnectionFactory; import javax.jms.JMSException; import javax.jms.TextMessage; import java.util.ArrayList; import java.util.List; import java.util.stream.Collectors; /** * Created by yangjunming on 6/20/16. */ public final class MessageUtil { private Logger logger = new MwLogger(MessageUtil.class);//这里就是一个Log4j2的实例,大家可以换成原生的log4j2或类似工具 private ConnectionFactory connectionFactory; private long receiveTimeout;//接收超时时间 private JmsTemplate jmsTemplate; private List destinationQueueNames; private final static String BACKUP_QUEUE_SUFFIX = "_B"; private boolean autoBackup = false;//是否自动将消息备份到_b的队列，方便调试 public MessageUtil(final ConnectionFactory connectionFactory, final long receiveTimeout, final List destinationQueueNames) { this.connectionFactory = connectionFactory; this.receiveTimeout = receiveTimeout; this.destinationQueueNames = new ArrayList(); this.destinationQueueNames.addAll(destinationQueueNames.stream().collect(Collectors.toList())); jmsTemplate = new JmsTemplate(this.connectionFactory); jmsTemplate.setReceiveTimeout(this.receiveTimeout); } public MessageUtil(ConnectionFactory connectionFactory, List destinationQueueNames) { this(connectionFactory, 10000, destinationQueueNames); } public void convertAndSend(Object message) { if (ListUtil.isEmpty(destinationQueueNames)) { logger.error("目标队列为空，无法发送，请检查配置！message => " + message.toString()); return; } for (String dest : destinationQueueNames) { jmsTemplate.convertAndSend(dest, message); if (autoBackup) { jmsTemplate.convertAndSend(dest + BACKUP_QUEUE_SUFFIX, message); } } } public void convertAndSend(Object message, MessagePostProcessor messagePostProcessor) { if (ListUtil.isEmpty(destinationQueueNames)) { logger.error("目标队列为空，无法发送，请检查配置！message => " + message.toString()); return; } for (String dest : destinationQueueNames) { jmsTemplate.convertAndSend(dest, message, messagePostProcessor); if (autoBackup) { jmsTemplate.convertAndSend(dest + BACKUP_QUEUE_SUFFIX, message, messagePostProcessor); } } } public void convertAndSend(String destinationName, Object message) { if (StringUtils.isBlank(destinationName)) { logger.error("目标队列为空，无法发送，请检查配置！message => " + message.toString()); return; } jmsTemplate.convertAndSend(destinationName, message); if (autoBackup) { jmsTemplate.convertAndSend(destinationName + BACKUP_QUEUE_SUFFIX, message); } } public void convertAndSend(String destinationName, Object message, MessagePostProcessor messagePostProcessor) { if (StringUtils.isBlank(destinationName)) { logger.error("目标队列为空，无法发送，请检查配置！message => " + message.toString()); return; } jmsTemplate.convertAndSend(destinationName, message, messagePostProcessor); if (autoBackup) { jmsTemplate.convertAndSend(destinationName + BACKUP_QUEUE_SUFFIX, message, messagePostProcessor); } } public static String getText(javax.jms.Message message) { if (message instanceof TextMessage) { try { return ((TextMessage) message).getText(); } catch (JMSException e) { return message.toString(); } } return message.toString(); } public String getFirstDestination() { if (ListUtil.isEmpty(destinationQueueNames)) { return null; } return destinationQueueNames.get(0); } public boolean isAutoBackup() { return autoBackup; } public void setAutoBackup(boolean autoBackup) { this.autoBackup = autoBackup; } }

其中主要就用到了convertAndSend(Object message, MessagePostProcessor messagePostProcessor) 这个方法，其它代码可以无视。

先来模拟瞬间向MQ发送大量延时消息：

/** * 发送延时消息 * * @param messageUtil */ private static void sendScheduleMessage(MessageUtil messageUtil) { for (int i = 0; i < 10000; i++) { Object obj = "test:" + i; messageUtil.convertAndSend(obj, new ScheduleMessagePostProcessor(1000 + i * 1000)); } }

这里向MQ发送了1w条延时消息，每条消息延时1秒*i，上面代码中的ScheduleMessagePostProcessor类可在上篇中找到。

运行完之后，MQ中应该堆积着了很多消息了：

下面的代码可以清空所有延时消息：

/** * 删除所有延时消息 * * @param connectionFactory * @throws JMSException */ private static void deleteAllScheduleMessage(final ConnectionFactory connectionFactory) throws JMSException { Connection conn = connectionFactory.createConnection(); Session session = conn.createSession(false, Session.AUTO_ACKNOWLEDGE); Destination management = session.createTopic(ScheduledMessage.AMQ_SCHEDULER_MANAGEMENT_DESTINATION); MessageProducer producer = session.createProducer(management); Message request = session.createMessage(); request.setStringProperty(ScheduledMessage.AMQ_SCHEDULER_ACTION, ScheduledMessage.AMQ_SCHEDULER_ACTION_REMOVEALL); producer.send(request); }

清空所有延时消息，有些用力过猛了，很多时候，我们只需要清理掉过期的延时消息（即：本来计划是8:00投递出去的消息，结果过了8点还没投递出去）

/** * 删除过期的延时消息 * * @param connectionFactory * @throws JMSException */ private static void deleteExpiredScheduleMessage(final ConnectionFactory connectionFactory) throws JMSException { long start = System.currentTimeMillis() - TimeUnit.HOURS.toMillis(12);//删除：当前时间前12小时范围的延时消息 long end = System.currentTimeMillis(); Connection conn = connectionFactory.createConnection(); Session session = conn.createSession(false, Session.AUTO_ACKNOWLEDGE); Destination management = session.createTopic(ScheduledMessage.AMQ_SCHEDULER_MANAGEMENT_DESTINATION); MessageProducer producer = session.createProducer(management); Message request = session.createMessage(); request.setStringProperty(ScheduledMessage.AMQ_SCHEDULER_ACTION, ScheduledMessage.AMQ_SCHEDULER_ACTION_REMOVEALL); request.setStringProperty(ScheduledMessage.AMQ_SCHEDULER_ACTION_START_TIME, Long.toString(start)); request.setStringProperty(ScheduledMessage.AMQ_SCHEDULER_ACTION_END_TIME, Long.toString(end)); producer.send(request); }

与上一段代码基本相似，只是多指定了删除消息的起止时间段。　　

最后贴一段spring的配置文件及main函数入口

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main函数：

public static void main(String[] args) throws InterruptedException, JMSException { ApplicationContext context = new ClassPathXmlApplicationContext("spring-sender.xml"); ConnectionFactory connectionFactory = context.getBean(ConnectionFactory.class, "jmsFactory"); MessageUtil messageUtil = context.getBean(MessageUtil.class); // sendScheduleMessage(messageUtil); // deleteAllScheduleMessage(connectionFactory); deleteExpiredScheduleMessage(connectionFactory); }

参考文章：

Enhanced JMS Scheduler in ActiveMQ

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