MQClientInstance#start-ScheduledTask()的核心代码

原创

用户8671053

修改于 2021-09-24 14:21:30

3000

修改于 2021-09-24 14:21:30

文章被收录于专栏：码农的生活

MQClientInstance#start-ScheduledTask()，核心代码如下：

private void startScheduledTask() {
    ......
    this.scheduledExecutorService.scheduleAtFixedRate(new Runnable() {

        @Override
        public void run() {
            try {
                //从nameserver更新最新的topic路由信息
                MQClientInstance.this.updateTopicRouteInfoFromNameServer();
            } catch (Exception e) {
                log.error("ScheduledTask updateTopicRouteInfoFromNameServer exception", e);
            }
        }
    }, 10, this.clientConfig.getPollNameServerInterval(), TimeUnit.MILLISECONDS);

    ......
}

/**
    * 从nameserver获取topic路由信息
    */
public TopicRouteData getTopicRouteInfoFromNameServer(final String topic, final long timeoutMillis,
                                                      boolean allowTopicNotExist) throws MQClientException, InterruptedException, RemotingTimeoutException, RemotingSendRequestException, RemotingConnectException {
    ......
    //向nameserver发送请求包，requestCode为RequestCode.GET_ROUTEINFO_BY_TOPIC
    RemotingCommand request = RemotingCommand.createRequestCommand(RequestCode.GET_ROUTEINFO_BY_TOPIC, requestHeader);
  ......
}

producer和NameServer之间通过netty进行网络传输，producer向NameServer发起的请求中添加注册码

RequestCode.GET_ROUTEINFO_BY_TOPIC。