zk服务器异常报警和线程服务关闭机制

这篇文章主要讲解了“zk服务器异常报警和线程服务关闭机制”，文中的讲解内容简单清晰，易于学习与理解，下面请大家跟着小编的思路慢慢深入，一起来研究和学习“zk服务器异常报警和线程服务关闭机制”吧！

主要查看ZooKeeperServer

监听与服务器关系类图

疑问：重要线程关闭或中断的时候？这个监听器在什么时候被调用呢？

接口 ZooKeeperServerListener

void notifyStopping(String threadName, int errorCode);

实现类ZooKeeperServerListenerImpl

@Override

public void notifyStopping(String threadName, int exitCode) {

LOG.info("Thread {} exits, error code {}", threadName, exitCode);

zkServer.setState(State.ERROR);

}

报警危机线程ZooKeeperCriticalThread继承了ZooKeeperThread

重新实现了父类方法，调用监听通知方法，改变服务状态

@Override protected void handleException(String threadName, Throwable e) { LOG.error("Severe unrecoverable error, from thread : {}", threadName, e); listener.notifyStopping(threadName, ExitCode.UNEXPECTED_ERROR.getValue()); ServerMetrics.getMetrics().UNRECOVERABLE_ERROR_COUNT.add(1); }

处理器实现ZooKeeperServerShutdownHandler

private final CountDownLatch shutdownLatch;

void handle(State state) { if (state == State.ERROR || state == State.SHUTDOWN) { shutdownLatch.countDown(); } }

把shutdownLatch减去1

1异常处理流程

SessionTrackerImpl 运行中如果遇到异常

catch (InterruptedException e) {

handleException(this.getName(), e);

}

2调用继承类的方法handleException

3方法中调用监听类ZooKeeperServerListener的.notifyStopping通知方法

4通知接口实现ZooKeeperServerListenerImpl具体指定处理

设置服务状态为zkServer.setState(State.ERROR);

5调用zkServer.setState方法，内部调用ZooKeeperServerShutdownHandler处理器方法

6处理器中调用handle方法

void handle(State state) {

if (state == State.ERROR || state == State.SHUTDOWN) {

shutdownLatch.countDown();

}

}

6 计数器关闭ZooKeeperServerMain中注册了关闭服务处理器

// Registers shutdown handler which will be used to know the

// server error or shutdown state changes.

final CountDownLatch shutdownLatch = new CountDownLatch(1);

zkServer.registerServerShutdownHandler(new ZooKeeperServerShutdownHandler(shutdownLatch));

...

containerManager.start();

// Watch status of ZooKeeper server. It will do a graceful shutdown

// if the server is not running or hits an internal error.

shutdownLatch.await();

感谢各位的阅读，以上就是“zk服务器异常报警和线程服务关闭机制”的内容了，经过本文的学习后，相信大家对zk服务器异常报警和线程服务关闭机制这一问题有了更深刻的体会，具体使用情况还需要大家实践验证。这里是亿速云，小编将为大家推送更多相关知识点的文章，欢迎关注！