RocketMQ源码解析-topic创建机制

2年前 (2022) 程序员胖胖胖虎阿
202 0 0
  1. RocketMQ Topic创建机制
    RocketMQ Topic创建机制分为两种:一种自动创建,一种手动创建。可以通过设置broker的配置文件来禁用或者允许自动创建。默认是开启的允许自动创建

autoCreateTopicEnable=true/false

下面会结合源码来深度分析一下自动创建和手动创建的过程。

  1. 自动Topic
    默认情况下,topic不用手动创建,当producer进行消息发送时,会从nameserver拉取topic的路由信息,如果topic的路由信息不存在,那么会默认拉取broker启动时默认创建好名为“TBW102”的Topic,这定义在org.apache.rocketmq.common.MixAll类中
    // Will be created at broker when isAutoCreateTopicEnable
    public static final String AUTO_CREATE_TOPIC_KEY_TOPIC = "TBW102";
    复制代码
    自动创建开关是下BrokerConfig类中有一个私有变量:
    @ImportantField
    private boolean autoCreateTopicEnable = true;
    复制代码
    这变量可以通过配置文件配置来进行修改,代码中的默认值为true,所以在默认的情况下Rocket MQ是会自动创建Topic的。
    在Broker启动,会调用TopicConfigManager的构造方法,在构造方法中定义了一系列RocketMQ系统内置的一些系统Topic(这里只关注一下TBW102):
    {
    // MixAll.AUTO_CREATE_TOPIC_KEY_TOPIC
    if (this.brokerController.getBrokerConfig().isAutoCreateTopicEnable()) {

     String topic = MixAll.AUTO_CREATE_TOPIC_KEY_TOPIC;
     TopicConfig topicConfig = new TopicConfig(topic);
     this.systemTopicList.add(topic);
     topicConfig.setReadQueueNums(this.brokerController.getBrokerConfig()
         .getDefaultTopicQueueNums()); //8
     topicConfig.setWriteQueueNums(this.brokerController.getBrokerConfig()
         .getDefaultTopicQueueNums()); //8
     int perm = PermName.PERM_INHERIT | PermName.PERM_READ | PermName.PERM_WRITE;
     topicConfig.setPerm(perm);
     this.topicConfigTable.put(topicConfig.getTopicName(), topicConfig);

    }
    }
    复制代码
    这里有 this.brokerController.getBrokerConfig().isAutoCreateTopicEnable() 这样一段代码,在开启允许自动创建的时候,会把当前Topic的信息存入topicConfigTable变量中。然后通过发送定期发送心跳包把Topic和Broker的信息发送到NameServer的RouteInfoManager中进行保存。在BrokerController中定义了这样的一个定时任务来执行这个心跳包的发送:
    this.scheduledExecutorService.scheduleAtFixedRate(new Runnable() {

         @Override
         public void run() {
             try {
                 BrokerController.this.registerBrokerAll(true, false, brokerConfig.isForceRegister());
             } catch (Throwable e) {
                 log.error("registerBrokerAll Exception", e);
             }
         }
     }, 1000 * 10, Math.max(10000, Math.min(brokerConfig.getRegisterNameServerPeriod(), 60000)), TimeUnit.MILLISECONDS);
    

复制代码
这里就说明了如何把每个Broker的系统自定义的Topic注册到NameServer。接下来看在发送过程中如何从NameServer获取Topic的路由信息:
DefaultMQProducerImpl.sendDefaultImpl
private SendResult sendDefaultImpl(

    Message msg,
    final CommunicationMode communicationMode,
    final SendCallback sendCallback,
    final long timeout
) throws MQClientException, RemotingException, MQBrokerException, InterruptedException {
    
    //省略代码
    
    //获取路由信息
    TopicPublishInfo topicPublishInfo = this.tryToFindTopicPublishInfo(msg.getTopic());
    
}

复制代码
通过DefaultMQProducerImpl.tryToFindTopicPublishInfo方法获取Topic的路由信息。

private TopicPublishInfo tryToFindTopicPublishInfo(final String topic) {
    
    TopicPublishInfo topicPublishInfo = this.topicPublishInfoTable.get(topic);
    //第一次从缓存中获取--肯定没有因为还没创建
    if (null == topicPublishInfo || !topicPublishInfo.ok()) {
        this.topicPublishInfoTable.putIfAbsent(topic, new TopicPublishInfo());
        //从NameServer获取--也是没有,因为没有创建
        this.mQClientFactory.updateTopicRouteInfoFromNameServer(topic);
        topicPublishInfo = this.topicPublishInfoTable.get(topic);
    }

    if (topicPublishInfo.isHaveTopicRouterInfo() || topicPublishInfo.ok()) {
        return topicPublishInfo;
    } else {
        //第二次从这里获取
        this.mQClientFactory.updateTopicRouteInfoFromNameServer(topic, true, this.defaultMQProducer);
        topicPublishInfo = this.topicPublishInfoTable.get(topic);
        return topicPublishInfo;
    }
}

复制代码
下面来看一下 MQClientInstance.updateTopicRouteInfoFromNameServer 的方法:
public boolean updateTopicRouteInfoFromNameServer(final String topic, boolean isDefault,

    DefaultMQProducer defaultMQProducer) {
        
//省略代码


if (isDefault && defaultMQProducer != null) {
        //使用默认的TBW102 Topic获取数据
        topicRouteData = this.mQClientAPIImpl.getDefaultTopicRouteInfoFromNameServer(defaultMQProducer.getCreateTopicKey(),
                        1000 * 3);
            if (topicRouteData != null) {
                for (QueueData data : topicRouteData.getQueueDatas()) {
                            int queueNums = Math.min(defaultMQProducer.getDefaultTopicQueueNums(), data.getReadQueueNums());
                            data.setReadQueueNums(queueNums);
                            data.setWriteQueueNums(queueNums);
                        }
                    }
                } else {
                    //这是正常的
                    topicRouteData = this.mQClientAPIImpl.getTopicRouteInfoFromNameServer(topic, 1000 * 3);
                }
  //省略代码      
}

复制代码
如果isDefault=true并且defaultMQProducer不为空,从nameserver中获取默认路由信息,此时会获取所有已开启自动创建开关的broker的默认“TBW102”topic路由信息,并保存默认的topic消息队列数量。

这里会比较一下配在在 DefaultMQProducer.defaultTopicQueueNums中的默认值和TBW102中的值哪个更小。

if (topicRouteData != null) {

    TopicRouteData old = this.topicRouteTable.get(topic);
    boolean changed = topicRouteDataIsChange(old, topicRouteData);
    if (!changed) {
        changed = this.isNeedUpdateTopicRouteInfo(topic);
    } else {
        log.info("the topic[{}] route info changed, old[{}] ,new[{}]", topic, old, topicRouteData);
    }

}
复制代码
判断获取默认的是否存在,如果存在把当前的Topic的信息更新。也就是把TBW102 Topic的数据更新为自动创建的数据。
if (changed) {

TopicRouteData cloneTopicRouteData = topicRouteData.cloneTopicRouteData();

for (BrokerData bd : topicRouteData.getBrokerDatas()) {
    this.brokerAddrTable.put(bd.getBrokerName(), bd.getBrokerAddrs());
}

// Update Pub info
{
    TopicPublishInfo publishInfo = topicRouteData2TopicPublishInfo(topic, topicRouteData);
    publishInfo.setHaveTopicRouterInfo(true);
    Iterator<Entry<String, MQProducerInner>> it = this.producerTable.entrySet().iterator();
    while (it.hasNext()) {
        Entry<String, MQProducerInner> entry = it.next();
        MQProducerInner impl = entry.getValue();
        if (impl != null) {
            impl.updateTopicPublishInfo(topic, publishInfo);
        }
    }
}
    // Update sub info
{
    Set<MessageQueue> subscribeInfo = topicRouteData2TopicSubscribeInfo(topic, topicRouteData);
    Iterator<Entry<String, MQConsumerInner>> it = this.consumerTable.entrySet().iterator();
    while (it.hasNext()) {
        Entry<String, MQConsumerInner> entry = it.next();
        MQConsumerInner impl = entry.getValue();
        if (impl != null) {
            impl.updateTopicSubscribeInfo(topic, subscribeInfo);
        }
    }
}
log.info("topicRouteTable.put. Topic = {}, TopicRouteData[{}]", topic, cloneTopicRouteData);
this.topicRouteTable.put(topic, cloneTopicRouteData);
return true;

}
复制代码
更新本地的缓存。这样TBW102 Topic的负载和一些默认的路由信息就会被自己创建的Topic使用。这里就是整个自动创建的过程.
总结一下就是:通过使用系统内部的一个TBW102的Topic的配置来自动创建当前用户的要创建的自定义Topic。

  1. 手动创建--预先创建
    手动创建也叫预先创建,就是在使用Topic之前就创建,可以通过命令行或者通过RocketMQ的管理界面创建Topic。
    通过界面控制台创建

项目地址: github.com/apache/rock…

RocketMQ源码解析-topic创建机制

TopicController主要负责Topic的管理
@RequestMapping(value = "/createOrUpdate.do", method = { RequestMethod.POST})
@ResponseBody
public Object topicCreateOrUpdateRequest(@RequestBody TopicConfigInfo topicCreateOrUpdateRequest) {

Preconditions.checkArgument(CollectionUtils.isNotEmpty(topicCreateOrUpdateRequest.getBrokerNameList()) || CollectionUtils.isNotEmpty(topicCreateOrUpdateRequest.getClusterNameList()),
        "clusterName or brokerName can not be all blank");
logger.info("op=look topicCreateOrUpdateRequest={}", JsonUtil.obj2String(topicCreateOrUpdateRequest));
topicService.createOrUpdate(topicCreateOrUpdateRequest);
return true;

}
复制代码
然后通过MQAdminExtImpl.createAndUpdateTopicConfig方法来创建:

@Override
public void createAndUpdateTopicConfig(String addr, TopicConfig config)
    throws RemotingException, MQBrokerException, InterruptedException, MQClientException {
    MQAdminInstance.threadLocalMQAdminExt().createAndUpdateTopicConfig(addr, config);
}

复制代码
通过调用DefaultMQAdminExtImpl.createAndUpdateTopicConfig创建Topic
@Override
public void createAndUpdateTopicConfig(String addr, TopicConfig config) throws RemotingException, MQBrokerException,

    InterruptedException, MQClientException {
this.mqClientInstance.getMQClientAPIImpl().createTopic(addr, this.defaultMQAdminExt.getCreateTopicKey(), config, timeoutMillis);

}
复制代码
最后通过MQClientAPIImpl.createTopic创建Topic

public void createTopic(final String addr, final String defaultTopic, final TopicConfig topicConfig,
    final long timeoutMillis)
    throws RemotingException, MQBrokerException, InterruptedException, MQClientException {
    CreateTopicRequestHeader requestHeader = new CreateTopicRequestHeader();
    requestHeader.setTopic(topicConfig.getTopicName());
    requestHeader.setDefaultTopic(defaultTopic);
    requestHeader.setReadQueueNums(topicConfig.getReadQueueNums());
    requestHeader.setWriteQueueNums(topicConfig.getWriteQueueNums());
    requestHeader.setPerm(topicConfig.getPerm());
    requestHeader.setTopicFilterType(topicConfig.getTopicFilterType().name());
    requestHeader.setTopicSysFlag(topicConfig.getTopicSysFlag());
    requestHeader.setOrder(topicConfig.isOrder());

    RemotingCommand request = RemotingCommand.createRequestCommand(RequestCode.UPDATE_AND_CREATE_TOPIC, requestHeader);

    RemotingCommand response = this.remotingClient.invokeSync(MixAll.brokerVIPChannel(this.clientConfig.isVipChannelEnabled(), addr),
        request, timeoutMillis);
    assert response != null;
    switch (response.getCode()) {
        case ResponseCode.SUCCESS: {
            return;
        }
        default:
            break;
    }

    throw new MQClientException(response.getCode(), response.getRemark());
}

版权声明:程序员胖胖胖虎阿 发表于 2022年11月5日 上午4:56。
转载请注明:RocketMQ源码解析-topic创建机制 | 胖虎的工具箱-编程导航

相关文章

暂无评论

暂无评论...