rocketmq顺序消费

ConsumeMessageOrderlyService

lockOneMQ

同步加锁 true:加锁成功

public synchronized boolean lockOneMQ(final MessageQueue mq) {
  if (!this.stopped) {
    return this.defaultMQPushConsumerImpl.getRebalanceImpl().lock(mq);
  }

  return false;
}

tryLockLaterAndReconsume

public void tryLockLaterAndReconsume(final MessageQueue mq, final ProcessQueue processQueue,
  final long delayMills) {
  this.scheduledExecutorService.schedule(new Runnable() {
    @Override
    public void run() {
      boolean lockOK = ConsumeMessageOrderlyService.this.lockOneMQ(mq); // 尝试获取锁
      if (lockOK) {
        ConsumeMessageOrderlyService.this.submitConsumeRequestLater(processQueue, mq, 10); // 锁住 等待10ms
      } else {
        ConsumeMessageOrderlyService.this.submitConsumeRequestLater(processQueue, mq, 3000); // 未锁住 等待3000ms
      }
    }
  }, delayMills, TimeUnit.MILLISECONDS);
}

submitConsumeRequestLater

private void submitConsumeRequestLater(
        final ProcessQueue processQueue,
        final MessageQueue messageQueue,
        final long suspendTimeMillis
) {
  long timeMillis = suspendTimeMillis;
  if (timeMillis == -1) {
    timeMillis = this.defaultMQPushConsumer.getSuspendCurrentQueueTimeMillis();
  }

  if (timeMillis < 10) {
    timeMillis = 10;
  } else if (timeMillis > 30000) {
    timeMillis = 30000;
  }

  this.scheduledExecutorService.schedule(new Runnable() {

    @Override
    public void run() {
      ConsumeMessageOrderlyService.this.submitConsumeRequest(null, processQueue, messageQueue, true);
    }
  }, timeMillis, TimeUnit.MILLISECONDS); // timeMillis之后执行(单位ms)
}

submitConsumeRequest

submitConsumeRequestLater过来的dispathToConsume=true

public void submitConsumeRequest(
  final List<MessageExt> msgs,
  final ProcessQueue processQueue,
  final MessageQueue messageQueue,
  final boolean dispathToConsume) {
  if (dispathToConsume) { // 封装ConsumeRequest 丢到consumeExecutor
    ConsumeRequest consumeRequest = new ConsumeRequest(processQueue, messageQueue);
    this.consumeExecutor.submit(consumeRequest);
  }
}

processConsumeResult

ConsumeMessageOrderlyService

public boolean processConsumeResult(
  final List<MessageExt> msgs,
  final ConsumeOrderlyStatus status,
  final ConsumeOrderlyContext context,
  final ConsumeRequest consumeRequest
) {
  boolean continueConsume = true;
  long commitOffset = -1L;
  if (context.isAutoCommit()) { // 自动提交
    switch (status) {
      case COMMIT:
      case ROLLBACK: 
        log.warn("the message queue consume result is illegal, we think you want to ack these message {}",
          consumeRequest.getMessageQueue());
      case SUCCESS:
        commitOffset = consumeRequest.getProcessQueue().commit(); // 提交
        this.getConsumerStatsManager().incConsumeOKTPS(consumerGroup, consumeRequest.getMessageQueue().getTopic(), msgs.size());
        break;
      case SUSPEND_CURRENT_QUEUE_A_MOMENT:
        this.getConsumerStatsManager().incConsumeFailedTPS(consumerGroup, consumeRequest.getMessageQueue().getTopic(), msgs.size());
        if (checkReconsumeTimes(msgs)) {
          consumeRequest.getProcessQueue().makeMessageToConsumeAgain(msgs); // consumingMsgOrderlyTreeMap-> msgTreeMap
          this.submitConsumeRequestLater(
            consumeRequest.getProcessQueue(),
            consumeRequest.getMessageQueue(),
            context.getSuspendCurrentQueueTimeMillis());
          continueConsume = false;
        } else {
          commitOffset = consumeRequest.getProcessQueue().commit();
        }
        break;
      default:
        break;
    }
  } else { // 非自动提交
    switch (status) {
      case SUCCESS:
        this.getConsumerStatsManager().incConsumeOKTPS(consumerGroup, consumeRequest.getMessageQueue().getTopic(), msgs.size());
        break;
      case COMMIT:
        commitOffset = consumeRequest.getProcessQueue().commit();
        break;
      case ROLLBACK:
        consumeRequest.getProcessQueue().rollback(); // rollback()  consumingMsgOrderlyTreeMap -> msgTreeMap
        this.submitConsumeRequestLater(
          consumeRequest.getProcessQueue(),
          consumeRequest.getMessageQueue(),
          context.getSuspendCurrentQueueTimeMillis()); // 重新执行
        continueConsume = false;
        break;
      case SUSPEND_CURRENT_QUEUE_A_MOMENT:
        this.getConsumerStatsManager().incConsumeFailedTPS(consumerGroup, consumeRequest.getMessageQueue().getTopic(), msgs.size());
        if (checkReconsumeTimes(msgs)) {
          consumeRequest.getProcessQueue().makeMessageToConsumeAgain(msgs); // consumingMsgOrderlyTreeMap-> msgTreeMap
          this.submitConsumeRequestLater(
            consumeRequest.getProcessQueue(),
            consumeRequest.getMessageQueue(),
            context.getSuspendCurrentQueueTimeMillis());
          continueConsume = false;
        }
        break;
      default:
        break;
    }
  }

  if (commitOffset >= 0 && !consumeRequest.getProcessQueue().isDropped()) { // todo 修改offset位置  顺序消费这里修改位置
    this.defaultMQPushConsumerImpl.getOffsetStore().updateOffset(consumeRequest.getMessageQueue(), commitOffset, false);
  }

  return continueConsume;
}

commit

public long commit() {
  try {
    this.lockTreeMap.writeLock().lockInterruptibly();
    try {
      Long offset = this.consumingMsgOrderlyTreeMap.lastKey(); // 最后1个
      msgCount.addAndGet(0 - this.consumingMsgOrderlyTreeMap.size());
      for (MessageExt msg : this.consumingMsgOrderlyTreeMap.values()) {
        msgSize.addAndGet(0 - msg.getBody().length);
      }
      this.consumingMsgOrderlyTreeMap.clear(); // 清空本次消费消息
      if (offset != null) {
        return offset + 1;
      }
    } finally {
      this.lockTreeMap.writeLock().unlock();
    }
  } catch (InterruptedException e) {
    log.error("commit exception", e);
  }

  return -1;
}

rollback()

public void rollback() {
  try {
    this.lockTreeMap.writeLock().lockInterruptibly();
    try {
      this.msgTreeMap.putAll(this.consumingMsgOrderlyTreeMap); // 退回到msgTreeMap
      this.consumingMsgOrderlyTreeMap.clear(); // 清空consumingMsgOrderlyTreeMap
    } finally {
      this.lockTreeMap.writeLock().unlock();
    }
  } catch (InterruptedException e) {
    log.error("rollback exception", e);
  }
}

getMaxReconsumeTimes

private int getMaxReconsumeTimes() {
  // default reconsume times: Integer.MAX_VALUE
  if (this.defaultMQPushConsumer.getMaxReconsumeTimes() == -1) { // 默认 defaultMQPushConsumer.getMaxReconsumeTimes()==-1
    return Integer.MAX_VALUE;
  } else {
    return this.defaultMQPushConsumer.getMaxReconsumeTimes();
  }
}