序
本文主要研究一下rocketmq的ConsumeMode.CONCURRENTLY
ConsumeMode.CONCURRENTLY
rocketmq-spring-boot-2.0.4-sources.jar!/org/apache/rocketmq/spring/annotation/ConsumeMode.java
public enum ConsumeMode {
/** * Receive asynchronously delivered messages concurrently */ CONCURRENTLY, /** * Receive asynchronously delivered messages orderly. one queue, one thread */ ORDERLY } - ConsumeMode定义了CONCURRENTLY、ORDERLY两个枚举值
DefaultRocketMQListenerContainer
rocketmq-spring-boot-2.0.4-sources.jar!/org/apache/rocketmq/spring/support/DefaultRocketMQListenerContainer.java
public class DefaultRocketMQListenerContainer implements InitializingBean, RocketMQListenerContainer, SmartLifecycle, ApplicationContextAware { //...... private void initRocketMQPushConsumer() throws MQClientException { Assert.notNull(rocketMQListener, "Property 'rocketMQListener' is required"); Assert.notNull(consumerGroup, "Property 'consumerGroup' is required"); Assert.notNull(nameServer, "Property 'nameServer' is required"); Assert.notNull(topic, "Property 'topic' is required"); RPCHook rpcHook = RocketMQUtil.getRPCHookByAkSk(applicationContext.getEnvironment(), this.rocketMQMessageListener.accessKey(), this.rocketMQMessageListener.secretKey()); boolean enableMsgTrace = rocketMQMessageListener.enableMsgTrace(); if (Objects.nonNull(rpcHook)) { consumer = new DefaultMQPushConsumer(consumerGroup, rpcHook, new AllocateMessageQueueAveragely(), enableMsgTrace, this.applicationContext.getEnvironment(). resolveRequiredPlaceholders(this.rocketMQMessageListener.customizedTraceTopic())); consumer.setVipChannelEnabled(false); consumer.setInstanceName(RocketMQUtil.getInstanceName(rpcHook, consumerGroup)); } else { log.debug("Access-key or secret-key not configure in " + this + "."); consumer = new DefaultMQPushConsumer(consumerGroup, enableMsgTrace, this.applicationContext.getEnvironment(). resolveRequiredPlaceholders(this.rocketMQMessageListener.customizedTraceTopic())); } String customizedNameServer = this.applicationContext.getEnvironment().resolveRequiredPlaceholders(this.rocketMQMessageListener.nameServer()); if (customizedNameServer != null) { consumer.setNamesrvAddr(customizedNameServer); } else { consumer.setNamesrvAddr(nameServer); } if (accessChannel != null) { consumer.setAccessChannel(accessChannel); } consumer.setConsumeThreadMax(consumeThreadMax); if (consumeThreadMax < consumer.getConsumeThreadMin()) { consumer.setConsumeThreadMin(consumeThreadMax); } consumer.setConsumeTimeout(consumeTimeout); switch (messageModel) { case BROADCASTING: consumer.setMessageModel(org.apache.rocketmq.common.protocol.heartbeat.MessageModel.BROADCASTING); break; case CLUSTERING: consumer.setMessageModel(org.apache.rocketmq.common.protocol.heartbeat.MessageModel.CLUSTERING); break; default: throw new IllegalArgumentException("Property 'messageModel' was wrong."); } switch (selectorType) { case TAG: consumer.subscribe(topic, selectorExpression); break; case SQL92: consumer.subscribe(topic, MessageSelector.bySql(selectorExpression)); break; default: throw new IllegalArgumentException("Property 'selectorType' was wrong."); } switch (consumeMode) { case ORDERLY: consumer.setMessageListener(new DefaultMessageListenerOrderly()); break; case CONCURRENTLY: consumer.setMessageListener(new DefaultMessageListenerConcurrently()); break; default: throw new IllegalArgumentException("Property 'consumeMode' was wrong."); } if (rocketMQListener instanceof RocketMQPushConsumerLifecycleListener) { ((RocketMQPushConsumerLifecycleListener) rocketMQListener).prepareStart(consumer); } } } - initRocketMQPushConsumer方法对于consumeMode为CONCURRENTLY则设置的messageListener为DefaultMessageListenerConcurrently
DefaultMessageListenerConcurrently
rocketmq-spring-boot-2.0.4-sources.jar!/org/apache/rocketmq/spring/support/DefaultRocketMQListenerContainer.java
public class DefaultMessageListenerConcurrently implements MessageListenerConcurrently { @SuppressWarnings("unchecked") @Override public ConsumeConcurrentlyStatus consumeMessage(List<MessageExt> msgs, ConsumeConcurrentlyContext context) { for (MessageExt messageExt : msgs) { log.debug("received msg: {}", messageExt); try { long now = System.currentTimeMillis(); rocketMQListener.onMessage(doConvertMessage(messageExt)); long costTime = System.currentTimeMillis() - now; log.debug("consume {} cost: {} ms", messageExt.getMsgId(), costTime); } catch (Exception e) { log.warn("consume message failed. messageExt:{}", messageExt, e); context.setDelayLevelWhenNextConsume(delayLevelWhenNextConsume); return ConsumeConcurrentlyStatus.RECONSUME_LATER; } } return ConsumeConcurrentlyStatus.CONSUME_SUCCESS; } } - DefaultMessageListenerConcurrently实现了MessageListenerConcurrently接口，其consumeMessage方法遍历msgs，然后挨个调用rocketMQListener.onMessage(doConvertMessage(messageExt))，若循环中出现异常被捕获住了会执行context.setDelayLevelWhenNextConsume(delayLevelWhenNextConsume)，然后返回ConsumeConcurrentlyStatus.RECONSUME_LATER
ConsumeMessageConcurrentlyService
rocketmq-client-4.6.0-sources.jar!/org/apache/rocketmq/client/impl/consumer/ConsumeMessageConcurrentlyService.java
class ConsumeRequest implements Runnable { private final List<MessageExt> msgs; private final ProcessQueue processQueue; private final MessageQueue messageQueue; public ConsumeRequest(List<MessageExt> msgs, ProcessQueue processQueue, MessageQueue messageQueue) { this.msgs = msgs; this.processQueue = processQueue; this.messageQueue = messageQueue; } public List<MessageExt> getMsgs() { return msgs; } public ProcessQueue getProcessQueue() { return processQueue; } @Override public void run() { if (this.processQueue.isDropped()) { log.info("the message queue not be able to consume, because it's dropped. group={} {}", ConsumeMessageConcurrentlyService.this.consumerGroup, this.messageQueue); return; } MessageListenerConcurrently listener = ConsumeMessageConcurrentlyService.this.messageListener; ConsumeConcurrentlyContext context = new ConsumeConcurrentlyContext(messageQueue); ConsumeConcurrentlyStatus status = null; defaultMQPushConsumerImpl.resetRetryAndNamespace(msgs, defaultMQPushConsumer.getConsumerGroup()); ConsumeMessageContext consumeMessageContext = null; if (ConsumeMessageConcurrentlyService.this.defaultMQPushConsumerImpl.hasHook()) { consumeMessageContext = new ConsumeMessageContext(); consumeMessageContext.setNamespace(defaultMQPushConsumer.getNamespace()); consumeMessageContext.setConsumerGroup(defaultMQPushConsumer.getConsumerGroup()); consumeMessageContext.setProps(new HashMap<String, String>()); consumeMessageContext.setMq(messageQueue); consumeMessageContext.setMsgList(msgs); consumeMessageContext.setSuccess(false); ConsumeMessageConcurrentlyService.this.defaultMQPushConsumerImpl.executeHookBefore(consumeMessageContext); } long beginTimestamp = System.currentTimeMillis(); boolean hasException = false; ConsumeReturnType returnType = ConsumeReturnType.SUCCESS; try { if (msgs != null && !msgs.isEmpty()) { for (MessageExt msg : msgs) { MessageAccessor.setConsumeStartTimeStamp(msg, String.valueOf(System.currentTimeMillis())); } } status = listener.consumeMessage(Collections.unmodifiableList(msgs), context); } catch (Throwable e) { log.warn("consumeMessage exception: {} Group: {} Msgs: {} MQ: {}", RemotingHelper.exceptionSimpleDesc(e), ConsumeMessageConcurrentlyService.this.consumerGroup, msgs, messageQueue); hasException = true; } long consumeRT = System.currentTimeMillis() - beginTimestamp; if (null == status) { if (hasException) { returnType = ConsumeReturnType.EXCEPTION; } else { returnType = ConsumeReturnType.RETURNNULL; } } else if (consumeRT >= defaultMQPushConsumer.getConsumeTimeout() * 60 * 1000) { returnType = ConsumeReturnType.TIME_OUT; } else if (ConsumeConcurrentlyStatus.RECONSUME_LATER == status) { returnType = ConsumeReturnType.FAILED; } else if (ConsumeConcurrentlyStatus.CONSUME_SUCCESS == status) { returnType = ConsumeReturnType.SUCCESS; } if (ConsumeMessageConcurrentlyService.this.defaultMQPushConsumerImpl.hasHook()) { consumeMessageContext.getProps().put(MixAll.CONSUME_CONTEXT_TYPE, returnType.name()); } if (null == status) { log.warn("consumeMessage return null, Group: {} Msgs: {} MQ: {}", ConsumeMessageConcurrentlyService.this.consumerGroup, msgs, messageQueue); status = ConsumeConcurrentlyStatus.RECONSUME_LATER; } if (ConsumeMessageConcurrentlyService.this.defaultMQPushConsumerImpl.hasHook()) { consumeMessageContext.setStatus(status.toString()); consumeMessageContext.setSuccess(ConsumeConcurrentlyStatus.CONSUME_SUCCESS == status); ConsumeMessageConcurrentlyService.this.defaultMQPushConsumerImpl.executeHookAfter(consumeMessageContext); } ConsumeMessageConcurrentlyService.this.getConsumerStatsManager() .incConsumeRT(ConsumeMessageConcurrentlyService.this.consumerGroup, messageQueue.getTopic(), consumeRT); if (!processQueue.isDropped()) { ConsumeMessageConcurrentlyService.this.processConsumeResult(status, context, this); } else { log.warn("processQueue is dropped without process consume result. messageQueue={}, msgs={}", messageQueue, msgs); } } public MessageQueue getMessageQueue() { return messageQueue; } } - ConsumeRequest实现了Runnable接口，它的构造器要求传入msgs、processQueue、messageQueue参数；其run方法会执行listener.consumeMessage(Collections.unmodifiableList(msgs), context)以及processConsumeResult(status, context, this)
小结
DefaultMessageListenerConcurrently实现了MessageListenerConcurrently接口，其consumeMessage方法遍历msgs，然后挨个调用rocketMQListener.onMessage(doConvertMessage(messageExt))，若循环中出现异常被捕获住了会执行context.setDelayLevelWhenNextConsume(delayLevelWhenNextConsume)，然后返回ConsumeConcurrentlyStatus.RECONSUME_LATER
ConsumeMessageConcurrentlyService.ConsumeRequest不需要自己去拉取msgs，而ConsumeMessageOrderlyService.ConsumeRequest需要自己先加锁，然后拉取msgs
doc
- ConsumeMessageConcurrentlyService
来源：哈尔滨网站优化