KafkaController分析7-启动流程

前面我们已经分析了KafkaController中使用的一系列组件, 从本章开始,我们开始介绍KafkaController的各个功能:

KafkaController分析1-选主和Failover

KafkaController分析2-NetworkClient分析

KafkaController分析3-ControllerChannelManager

KafkaController分析4-Partition选主

KafkaController分析5-Partition状态机

KafkaController分析6-Replica状态机

KafkaController启动流程

• 注册zk的SessionExpiration事件通知:registerSessionExpirationListener, 当session到期且新session建立后,进行controller的重新选主;

def handleNewSession() {
      info("ZK expired; shut down all controller components and try to re-elect")
      inLock(controllerContext.controllerLock) {
        onControllerResignation()
        controllerElector.elect
      }
    }

• 启动 ZookeeperLeaderElector:controllerElector.startup. 如果当前broker成功选为Controller, 则onControllerFailover回调被触发.

      readControllerEpochFromZookeeper()
      incrementControllerEpoch(zkUtils.zkClient)
      registerReassignedPartitionsListener()
      registerIsrChangeNotificationListener()
      registerPreferredReplicaElectionListener()
      partitionStateMachine.registerListeners()
      replicaStateMachine.registerListeners()
      initializeControllerContext()
      replicaStateMachine.startup()
      partitionStateMachine.startup()
      brokerState.newState(RunningAsController)
      maybeTriggerPartitionReassignment()
      maybeTriggerPreferredReplicaElection()
      sendUpdateMetadataRequest(controllerContext.liveOrShuttingDownBrokerIds.toSeq)
      if (config.autoLeaderRebalanceEnable) {
        autoRebalanceScheduler.startup()
        autoRebalanceScheduler.schedule("partition-rebalance-thread", checkAndTriggerPartitionRebalance,
          5, config.leaderImbalanceCheckIntervalSeconds.toLong, TimeUnit.SECONDS)
      }
      deleteTopicManager.start()

1. 更新zk上的controller epoch信息;
2. 注册zk上的broker/topic节点变化事件通知;
3. 初始化ControllerContext, 主要是从zk上获取broker, topic, parition, isr, partition leader, replicas等信息;
4. 启动ReplicaStateMachine;
5. 启动PartitionStateMachine;
6. 发送所有的partition信息(leader, isr, replica, epoch等)到所有的 live brokers;
7. 如果允许自动leader rebalance的话, 则启动AutoRebalanceScheduler;
8. 启动TopicDeletionManager;

• KafkaController的启动图解:

KafkaController.png

Kafka源码分析-汇总