聊聊rocketmq的MQFaultStrategy

序

本文主要研究一下rocketmq的MQFaultStrategy

MQFaultStrategy

rocketmq-client-4.6.0-sources.jar!/org/apache/rocketmq/client/latency/MQFaultStrategy.java

public class MQFaultStrategy {
    private final static InternalLogger log = ClientLogger.getLog();
    private final LatencyFaultTolerance<String> latencyFaultTolerance = new LatencyFaultToleranceImpl();

    private boolean sendLatencyFaultEnable = false;

    private long[] latencyMax = {50L, 100L, 550L, 1000L, 2000L, 3000L, 15000L};
    private long[] notAvailableDuration = {0L, 0L, 30000L, 60000L, 120000L, 180000L, 600000L};

    public long[] getNotAvailableDuration() {
        return notAvailableDuration;
    }

    public void setNotAvailableDuration(final long[] notAvailableDuration) {
        this.notAvailableDuration = notAvailableDuration;
    }

    public long[] getLatencyMax() {
        return latencyMax;
    }

    public void setLatencyMax(final long[] latencyMax) {
        this.latencyMax = latencyMax;
    }

    public boolean isSendLatencyFaultEnable() {
        return sendLatencyFaultEnable;
    }

    public void setSendLatencyFaultEnable(final boolean sendLatencyFaultEnable) {
        this.sendLatencyFaultEnable = sendLatencyFaultEnable;
    }

    public MessageQueue selectOneMessageQueue(final TopicPublishInfo tpInfo, final String lastBrokerName) {
        if (this.sendLatencyFaultEnable) {
            try {
                int index = tpInfo.getSendWhichQueue().getAndIncrement();
                for (int i = 0; i < tpInfo.getMessageQueueList().size(); i++) {
                    int pos = Math.abs(index++) % tpInfo.getMessageQueueList().size();
                    if (pos < 0)
                        pos = 0;
                    MessageQueue mq = tpInfo.getMessageQueueList().get(pos);
                    if (latencyFaultTolerance.isAvailable(mq.getBrokerName())) {
                        if (null == lastBrokerName || mq.getBrokerName().equals(lastBrokerName))
                            return mq;
                    }
                }

                final String notBestBroker = latencyFaultTolerance.pickOneAtLeast();
                int writeQueueNums = tpInfo.getQueueIdByBroker(notBestBroker);
                if (writeQueueNums > 0) {
                    final MessageQueue mq = tpInfo.selectOneMessageQueue();
                    if (notBestBroker != null) {
                        mq.setBrokerName(notBestBroker);
                        mq.setQueueId(tpInfo.getSendWhichQueue().getAndIncrement() % writeQueueNums);
                    }
                    return mq;
                } else {
                    latencyFaultTolerance.remove(notBestBroker);
                }
            } catch (Exception e) {
                log.error("Error occurred when selecting message queue", e);
            }

            return tpInfo.selectOneMessageQueue();
        }

        return tpInfo.selectOneMessageQueue(lastBrokerName);
    }

    public void updateFaultItem(final String brokerName, final long currentLatency, boolean isolation) {
        if (this.sendLatencyFaultEnable) {
            long duration = computeNotAvailableDuration(isolation ? 30000 : currentLatency);
            this.latencyFaultTolerance.updateFaultItem(brokerName, currentLatency, duration);
        }
    }

    private long computeNotAvailableDuration(final long currentLatency) {
        for (int i = latencyMax.length - 1; i >= 0; i--) {
            if (currentLatency >= latencyMax[i])
                return this.notAvailableDuration[i];
        }

        return 0;
    }
}

• MQFaultStrategy定义了latencyFaultTolerance、sendLatencyFaultEnable、latencyMax、notAvailableDuration属性；其selectOneMessageQueue方法在sendLatencyFaultEnable为false的时候使用的是tpInfo.selectOneMessageQueue(lastBrokerName)；在sendLatencyFaultEnable为true时，先通过tpInfo.getSendWhichQueue().getAndIncrement()获取index，之后遍历tpInfo.getMessageQueueList()，计算pos(Math.abs(index++) % tpInfo.getMessageQueueList().size())，若小于0则重置为0；然后使用latencyFaultTolerance.isAvailable来判断是否可用，若可用且null == lastBrokerName或者mq.getBrokerName().equals(lastBrokerName)则返回该MessageQueue
• selectOneMessageQueue方法在sendLatencyFaultEnable为true时，若遍历tpInfo.getMessageQueueList()都不可用，则通过latencyFaultTolerance.pickOneAtLeast()方法来选择notBestBroker，若其writeQueueNums大于0，则通过tpInfo.selectOneMessageQueue()选择MessageQueue，设置其brokerName为notBestBroker，设置其queueId为(tpInfo.getSendWhichQueue().getAndIncrement() % writeQueueNums)；若writeQueueNums小于等于0则执行latencyFaultTolerance.remove(notBestBroker)；如果前面没有选出MessageQueue则最后使用tpInfo.selectOneMessageQueue()
• 其updateFaultItem方法在sendLatencyFaultEnable为true时会使用computeNotAvailableDuration计算duration，然后通过latencyFaultTolerance.updateFaultItem(brokerName, currentLatency, duration)来更新；computeNotAvailableDuration方法则从后开始遍历latencyMax，在找到currentLatency >= latencyMax[i]时返回notAvailableDuration[i]，否则最后返回0

DefaultMQProducerImpl

rocketmq-client-4.6.0-sources.jar!/org/apache/rocketmq/client/impl/producer/DefaultMQProducerImpl.java

public class DefaultMQProducerImpl implements MQProducerInner {
    private final InternalLogger log = ClientLogger.getLog();
    private final Random random = new Random();
    private final DefaultMQProducer defaultMQProducer;
    private final ConcurrentMap<String/* topic */, TopicPublishInfo> topicPublishInfoTable =
        new ConcurrentHashMap<String, TopicPublishInfo>();
    private final ArrayList<SendMessageHook> sendMessageHookList = new ArrayList<SendMessageHook>();
    private final RPCHook rpcHook;
    private final BlockingQueue<Runnable> asyncSenderThreadPoolQueue;
    private final ExecutorService defaultAsyncSenderExecutor;
    private final Timer timer = new Timer("RequestHouseKeepingService", true);
    protected BlockingQueue<Runnable> checkRequestQueue;
    protected ExecutorService checkExecutor;
    private ServiceState serviceState = ServiceState.CREATE_JUST;
    private MQClientInstance mQClientFactory;
    private ArrayList<CheckForbiddenHook> checkForbiddenHookList = new ArrayList<CheckForbiddenHook>();
    private int zipCompressLevel = Integer.parseInt(System.getProperty(MixAll.MESSAGE_COMPRESS_LEVEL, "5"));
    private MQFaultStrategy mqFaultStrategy = new MQFaultStrategy();
    private ExecutorService asyncSenderExecutor;

    //......

    public MessageQueue selectOneMessageQueue(final TopicPublishInfo tpInfo, final String lastBrokerName) {
        return this.mqFaultStrategy.selectOneMessageQueue(tpInfo, lastBrokerName);
    }

    public void updateFaultItem(final String brokerName, final long currentLatency, boolean isolation) {
        this.mqFaultStrategy.updateFaultItem(brokerName, currentLatency, isolation);
    }

    //......
}

• DefaultMQProducerImpl的selectOneMessageQueue、updateFaultItem方法均委托给mqFaultStrategy来执行

小结

• MQFaultStrategy定义了latencyFaultTolerance、sendLatencyFaultEnable、latencyMax、notAvailableDuration属性；其selectOneMessageQueue方法在sendLatencyFaultEnable为false的时候使用的是tpInfo.selectOneMessageQueue(lastBrokerName)；在sendLatencyFaultEnable为true时，先通过tpInfo.getSendWhichQueue().getAndIncrement()获取index，之后遍历tpInfo.getMessageQueueList()，计算pos(Math.abs(index++) % tpInfo.getMessageQueueList().size())，若小于0则重置为0；然后使用latencyFaultTolerance.isAvailable来判断是否可用，若可用且null == lastBrokerName或者mq.getBrokerName().equals(lastBrokerName)则返回该MessageQueue
• selectOneMessageQueue方法在sendLatencyFaultEnable为true时，若遍历tpInfo.getMessageQueueList()都不可用，则通过latencyFaultTolerance.pickOneAtLeast()方法来选择notBestBroker，若其writeQueueNums大于0，则通过tpInfo.selectOneMessageQueue()选择MessageQueue，设置其brokerName为notBestBroker，设置其queueId为(tpInfo.getSendWhichQueue().getAndIncrement() % writeQueueNums)；若writeQueueNums小于等于0则执行latencyFaultTolerance.remove(notBestBroker)；如果前面没有选出MessageQueue则最后使用tpInfo.selectOneMessageQueue()
• 其updateFaultItem方法在sendLatencyFaultEnable为true时会使用computeNotAvailableDuration计算duration，然后通过latencyFaultTolerance.updateFaultItem(brokerName, currentLatency, duration)来更新；computeNotAvailableDuration方法则从后开始遍历latencyMax，在找到currentLatency >= latencyMax[i]时返回notAvailableDuration[i]，否则最后返回0

doc

• MQFaultStrategy