Java LeaderLatchListener类代码示例

import org.apache.curator.framework.recipes.leader.LeaderLatchListener; //导入依赖的package包/类
@Override
public void run(String... strings) throws Exception {
    client = CuratorFrameworkFactory.newClient(zookeeperConnString,
            new ExponentialBackoffRetry(1000, Integer.MAX_VALUE));
    client.start();
    client.getZookeeperClient().blockUntilConnectedOrTimedOut();

    leaderLatch = new LeaderLatch(client, "/http-job-scheduler/leader",
            ManagementFactory.getRuntimeMXBean().getName());

    leaderLatch.addListener(new LeaderLatchListener() {
        @Override
        public void isLeader() {
            setMaster(true);
            masterJobScheduler.resume();
        }

        @Override
        public void notLeader() {
            setMaster(false);
            masterJobScheduler.pause();
        }
    });
    leaderLatch.start();
}
 

import org.apache.curator.framework.recipes.leader.LeaderLatchListener; //导入依赖的package包/类
/**
 * 异步选主，只能启动一次
 *
 * @param listener 选主监听器
 */
public void startLeaderElect(final LeaderLatchListener listener) {
    executor.submit(new Runnable() {
        @Override
        public void run() {
            boolean errFlag = true;
            leaderLatch = new LeaderLatch((CuratorFramework) registryCenter.getRawClient(), ConsoleNode.LATCH);
            leaderLatch.addListener(listener);
            do {
                try {
                    leaderLatch.start();
                    leaderLatch.await();
                } catch (Exception e) {
                    log.error("Failed to elect a Leader! will retry", e);
                    errFlag = false;
                }
            } while (!errFlag);
        }
    });
}
 

import org.apache.curator.framework.recipes.leader.LeaderLatchListener; //导入依赖的package包/类
@Override
public void elect() throws Exception {
	
	zkClient.createContainers(ctx.getLeaderElectionZKPath());
	
	latch = new LeaderLatch(zkClient, ctx.getLeaderElectionZKPath(), ctx.getLeaderElectionID());
	latch.addListener(new LeaderLatchListener() {

		@Override
		public void notLeader() {
		}

		@Override
		public void isLeader() {
		}
	});

	latch.start();
	logger.info("[elect]{}", ctx);
}
 

import org.apache.curator.framework.recipes.leader.LeaderLatchListener; //导入依赖的package包/类
private void addListenerToLeaderLatch(LeaderLatch leaderLatch)
{

    LeaderLatchListener listener = new LeaderLatchListener()
    {
        @Override
        public void isLeader()
        {
            reapingIsActive.set(true);
            for ( PathHolder holder : activePaths.values() )
            {
                schedule(holder, reapingThresholdMs);
            }
        }

        @Override
        public void notLeader()
        {
            reapingIsActive.set(false);
        }
    };
    leaderLatch.addListener(listener);

    reapingIsActive.set(leaderLatch.hasLeadership());
}
 

import org.apache.curator.framework.recipes.leader.LeaderLatchListener; //导入依赖的package包/类
@SuppressWarnings("resource")
@Override
public void process() {
    try {
        CuratorFramework _curator = CuratorContainer.getInstance().getCurator();
        HeartBeatVo conf = HeartBeatConfigContainer.getInstance().getHbConf();
        CuratorContainer.getInstance().createZkNode(conf.getLeaderPath());

        // 获取进程ID和服务器hostName
        final BrokerInfoVo brokerInfo = new BrokerInfoVo();
        String name = ManagementFactory.getRuntimeMXBean().getName();
        String[] pidAndHostName = StringUtils.split(name, "@");
        brokerInfo.setPid(pidAndHostName[0]);
        brokerInfo.setHostName(pidAndHostName[1]);
        brokerInfo.setIp(InetAddress.getLocalHost().getHostAddress());
        LeaderLatch ll = new LeaderLatch(_curator, conf.getLeaderPath(), JsonUtil.toJson(brokerInfo));

        ll.addListener(new LeaderLatchListener() {
            @Override
            public void notLeader() {
                LoggerFactory.getLogger().error("本机现在切换到非leader状态,准备终止当前进程PID:{}", brokerInfo.getPid());
                System.exit(-1);
            }
            @Override
            public void isLeader() {
                LoggerFactory.getLogger().info("本机现在切换到leader状态.");
            }
        });

        ll.start();
        ll.await();
        // 注册控制事件
        CuratorContainer.getInstance().createZkNode(conf.getControlPath());
        _curator.getData().usingWatcher(WatcherType.CONTROL).forPath(conf.getControlPath());
    } catch (Exception e) {
        throw new RuntimeException("选举leader时发生错误!", e);
    }
}
 

import org.apache.curator.framework.recipes.leader.LeaderLatchListener; //导入依赖的package包/类
@Inject
public SingularityLeaderLatch(@Named(SingularityMainModule.HTTP_HOST_AND_PORT) final HostAndPort httpHostAndPort,
    final CuratorFramework curatorFramework, final Set<LeaderLatchListener> listeners) throws Exception {
  super(checkNotNull(curatorFramework, "curatorFramework is null"), LEADER_PATH, httpHostAndPort.toString());

  checkNotNull(listeners, "listeners is null");
  for (LeaderLatchListener listener : listeners) {
    addListener(listener);
  }
}
 

import org.apache.curator.framework.recipes.leader.LeaderLatchListener; //导入依赖的package包/类
public LeaderLatchListener getLatchListener() {
    return new LeaderLatchListener() {
        @Override
        public void isLeader() {
            log.info(name+" =>  isLeader() ");
            doJob();
        }

        @Override
        public void notLeader() {
            log.info(name+" =>relinquishing  notLeader");
        }
    };
}
 

import org.apache.curator.framework.recipes.leader.LeaderLatchListener; //导入依赖的package包/类
private LeaderLatchListener createLeaderLatchListener() {
    return new LeaderLatchListener() {
        @Override
        public void isLeader() {
            LOG.info("This instance with id [{}] acquired leadership", serverUrl);
        }

        @Override
        public void notLeader() {
            LOG.info("This instance with id [{}] lost leadership", serverUrl);
        }
    };
}
 

import org.apache.curator.framework.recipes.leader.LeaderLatchListener; //导入依赖的package包/类
/**
 * 阻塞式的初始化和Zookeeper的连接，这个方法在一个容器生命周期中只允许允许一次。
 * <p/>
 * 和zookeeper之间的连接遵循每实例一个ZkClientProvider的方式，这样当实例内部有多个同步线程的时候，
 * 可以共享一个ZkClientProvider，状态都是一致的，避免有些线程是leader，有些是standby的情况。
 * <p/>
 * 改方法是全异步的，如果zookeeper连接不上，也会返回。但是一般上层应用拿不到leader latch，不会成为leader。
 * 而且<code>apache.zookeeper.ClientCnxn</code>包的日志会打印如下：
 * <pre>
 *     Unable to read additional data from server sessionid 0x0, likely server has closed socket, closing socket
 *     connection and attempting reconnect
 * </pre>
 * 参数<code>name</code>标示同步线程的名称，默认的话只有一个可以初始化好和zk的连接，其他的都不再重复初始化了。
 */
@Override
public void init(String name) {
    if (!state.compareAndSet(State.LATENT, State.STARTED)) {
        logger.debug("ZkHaGuard can only be initialized once because LeaderLatch should be singleton");
        return;
    }

    if (zkClientProvider == null) {
        throw new IllegalStateException("ZkClientProvider should not be null");
    }
    logger.info("LeaderLatch will start soon by " + name);
    zkClientProvider.init();
    leaderLatch = new LeaderLatch(zkClientProvider.provideClient(), latchPath, NetUtils.getLocalHostIP());
    leaderLatch.addListener(new LeaderLatchListener() {
        @Override
        public void isLeader() {
            logger.info("This instance is leader");
        }

        @Override
        public void notLeader() {
            logger.warn("This instance is NOT leader");
        }
    });
    try {
        leaderLatch.start();
    } catch (Exception e) {
        throw new RuntimeException("Leader latch init failed", e);
    }
    logger.info("LeaderLatch starts by " + name + " asynchronously");
}
 

import org.apache.curator.framework.recipes.leader.LeaderLatchListener; //导入依赖的package包/类
@Override
public void configure(Binder binder) {
  binder.bind(HostAndPort.class).annotatedWith(named(HTTP_HOST_AND_PORT)).toProvider(SingularityHostAndPortProvider.class).in(Scopes.SINGLETON);

  binder.bind(LeaderLatch.class).to(SingularityLeaderLatch.class).in(Scopes.SINGLETON);
  binder.bind(CuratorFramework.class).toProvider(SingularityCuratorProvider.class).in(Scopes.SINGLETON);

  Multibinder<ConnectionStateListener> connectionStateListeners = Multibinder.newSetBinder(binder, ConnectionStateListener.class);
  connectionStateListeners.addBinding().to(SingularityAbort.class).in(Scopes.SINGLETON);

  Multibinder<LeaderLatchListener> leaderLatchListeners = Multibinder.newSetBinder(binder, LeaderLatchListener.class);
  leaderLatchListeners.addBinding().to(SingularityLeaderController.class).in(Scopes.SINGLETON);

  binder.bind(SingularityDriverManager.class).in(Scopes.SINGLETON);
  binder.bind(SingularityLeaderController.class).in(Scopes.SINGLETON);
  binder.bind(SingularityMailer.class).in(Scopes.SINGLETON);
  binder.bind(SingularitySmtpSender.class).in(Scopes.SINGLETON);
  binder.bind(MailTemplateHelpers.class).in(Scopes.SINGLETON);
  binder.bind(SingularityExceptionNotifier.class).in(Scopes.SINGLETON);
  binder.bind(LoadBalancerClient.class).to(LoadBalancerClientImpl.class).in(Scopes.SINGLETON);
  binder.bind(SingularityMailRecordCleaner.class).in(Scopes.SINGLETON);

  binder.bind(SingularityWebhookPoller.class).in(Scopes.SINGLETON);

  binder.bind(MesosClient.class).in(Scopes.SINGLETON);

  binder.bind(SingularityAbort.class).in(Scopes.SINGLETON);
  binder.bind(SingularityExceptionNotifierManaged.class).in(Scopes.SINGLETON);
  binder.bind(SingularityWebhookSender.class).in(Scopes.SINGLETON);

  binder.bind(NotifyingExceptionMapper.class).in(Scopes.SINGLETON);

  binder.bind(ObjectMapper.class).toProvider(DropwizardObjectMapperProvider.class).in(Scopes.SINGLETON);
  binder.bind(MetricRegistry.class).toProvider(DropwizardMetricRegistryProvider.class).in(Scopes.SINGLETON);

  binder.bind(AsyncHttpClient.class).to(SingularityHttpClient.class).in(Scopes.SINGLETON);
  binder.bind(ServerProvider.class).in(Scopes.SINGLETON);

  binder.bind(SingularityDropwizardHealthcheck.class).in(Scopes.SINGLETON);
  binder.bindConstant().annotatedWith(Names.named(SERVER_ID_PROPERTY)).to(UUID.randomUUID().toString());

  binder.bind(SingularityManagedScheduledExecutorServiceFactory.class).in(Scopes.SINGLETON);

  binder.bind(ScheduledExecutorService.class).annotatedWith(HEALTHCHECK_THREADPOOL_NAMED).toProvider(new SingularityManagedScheduledExecutorServiceProvider(configuration.getHealthcheckStartThreads(),
          configuration.getThreadpoolShutdownDelayInSeconds(),
          "healthcheck")).in(Scopes.SINGLETON);

  binder.bind(ScheduledExecutorService.class).annotatedWith(NEW_TASK_THREADPOOL_NAMED).toProvider(new SingularityManagedScheduledExecutorServiceProvider(configuration.getCheckNewTasksScheduledThreads(),
      configuration.getThreadpoolShutdownDelayInSeconds(),
      "check-new-task")).in(Scopes.SINGLETON);

  binder.bind(SingularityGraphiteReporterManaged.class).in(Scopes.SINGLETON);
}
 

import org.apache.curator.framework.recipes.leader.LeaderLatchListener; //导入依赖的package包/类
public SwitchLeadershipData(LeaderLatch latch, ControlChangeCallback cb,
                            LeaderLatchListener listener) {
    this.latch = latch;
    this.cb = cb;
    this.listener = listener;
}
 

import org.apache.curator.framework.recipes.leader.LeaderLatchListener; //导入依赖的package包/类
public LeaderLatchListener getListener() {
    return listener;
}
 

import org.apache.curator.framework.recipes.leader.LeaderLatchListener; //导入依赖的package包/类
@Override
public void configure(Binder binder) {
  binder.bind(HostAndPort.class).annotatedWith(named(HTTP_HOST_AND_PORT)).toProvider(SingularityHostAndPortProvider.class).in(Scopes.SINGLETON);

  binder.bind(LeaderLatch.class).to(SingularityLeaderLatch.class).in(Scopes.SINGLETON);
  binder.bind(CuratorFramework.class).toProvider(SingularityCuratorProvider.class).in(Scopes.SINGLETON);

  Multibinder<ConnectionStateListener> connectionStateListeners = Multibinder.newSetBinder(binder, ConnectionStateListener.class);
  connectionStateListeners.addBinding().to(SingularityAbort.class).in(Scopes.SINGLETON);

  Multibinder<LeaderLatchListener> leaderLatchListeners = Multibinder.newSetBinder(binder, LeaderLatchListener.class);
  leaderLatchListeners.addBinding().to(SingularityLeaderController.class).in(Scopes.SINGLETON);

  binder.bind(SingularityLeaderController.class).in(Scopes.SINGLETON);
  if (configuration.getSmtpConfigurationOptional().isPresent()) {
    binder.bind(SingularityMailer.class).to(SmtpMailer.class).in(Scopes.SINGLETON);
  } else {
    binder.bind(SingularityMailer.class).toInstance(NoopMailer.getInstance());
  }
  binder.bind(SingularitySmtpSender.class).in(Scopes.SINGLETON);
  binder.bind(MailTemplateHelpers.class).in(Scopes.SINGLETON);
  binder.bind(SingularityExceptionNotifier.class).in(Scopes.SINGLETON);
  binder.bind(LoadBalancerClient.class).to(LoadBalancerClientImpl.class).in(Scopes.SINGLETON);
  binder.bind(SingularityMailRecordCleaner.class).in(Scopes.SINGLETON);

  binder.bind(SingularityWebhookPoller.class).in(Scopes.SINGLETON);

  binder.bind(SingularityAbort.class).in(Scopes.SINGLETON);
  binder.bind(SingularityExceptionNotifierManaged.class).in(Scopes.SINGLETON);
  binder.bind(SingularityWebhookSender.class).in(Scopes.SINGLETON);

  binder.bind(SingularityUsageHelper.class).in(Scopes.SINGLETON);

  binder.bind(NotifyingExceptionMapper.class).in(Scopes.SINGLETON);

  binder.bind(ObjectMapper.class).toProvider(DropwizardObjectMapperProvider.class).in(Scopes.SINGLETON);
  binder.bind(MetricRegistry.class).toProvider(DropwizardMetricRegistryProvider.class).in(Scopes.SINGLETON);

  binder.bind(AsyncHttpClient.class).to(SingularityAsyncHttpClient.class).in(Scopes.SINGLETON);
  binder.bind(ServerProvider.class).in(Scopes.SINGLETON);

  binder.bind(SingularityDropwizardHealthcheck.class).in(Scopes.SINGLETON);
  binder.bindConstant().annotatedWith(Names.named(SERVER_ID_PROPERTY)).to(UUID.randomUUID().toString());

  binder.bind(SingularityManagedScheduledExecutorServiceFactory.class).in(Scopes.SINGLETON);

  binder.bind(ScheduledExecutorService.class).annotatedWith(HEALTHCHECK_THREADPOOL_NAMED).toProvider(new SingularityManagedScheduledExecutorServiceProvider(configuration.getHealthcheckStartThreads(),
          configuration.getThreadpoolShutdownDelayInSeconds(),
          "healthcheck")).in(Scopes.SINGLETON);

  binder.bind(ScheduledExecutorService.class).annotatedWith(NEW_TASK_THREADPOOL_NAMED).toProvider(new SingularityManagedScheduledExecutorServiceProvider(configuration.getCheckNewTasksScheduledThreads(),
      configuration.getThreadpoolShutdownDelayInSeconds(),
      "check-new-task")).in(Scopes.SINGLETON);

  binder.bind(SingularityGraphiteReporterManaged.class).in(Scopes.SINGLETON);

  binder.bind(SingularityMesosStatusUpdateHandler.class).in(Scopes.SINGLETON);

  if (configuration.isCacheOffers()) {
    binder.bind(OfferCache.class).to(SingularityOfferCache.class).in(Scopes.SINGLETON);
  } else {
    binder.bind(OfferCache.class).to(SingularityNoOfferCache.class).in(Scopes.SINGLETON);
  }
}
 

import org.apache.curator.framework.recipes.leader.LeaderLatchListener; //导入依赖的package包/类
public AttachLeaderSelectorListener(final LeaderLatchListener listener, final String path)
{
    this.listener = listener;
    this.path     = path;
}