Example usage for org.apache.zookeeper CreateMode EPHEMERAL

Introduction

In this page you can find the example usage for org.apache.zookeeper CreateMode EPHEMERAL.

Prototype

CreateMode EPHEMERAL

To view the source code for org.apache.zookeeper CreateMode EPHEMERAL.

Click Source Link

Document

The znode will be deleted upon the client's disconnect.

Usage

From source file:ZookeeperBackedAdoptionLogicImpl.java

License:Open Source License

public void advertisePartitionForAdoption(Partition partitionToGiveOut) throws Exception {
    //clear any previous ads by this broker
    List<String> prevAds = Utils.getAdoptionAds(client);
    String localBrokerId = "" + Utils.getLocalBrokerId();
    for (String prevAd : prevAds) {
        if (prevAd.startsWith(localBrokerId)) {
            logger.debug("Deleting previous Ad posting {}", prevAd);
            client.delete().forPath(ADOPTION_ADS_ROOT_ZNODE + "/" + prevAd);
        }// w ww  .  j av a2 s. co m
    }

    String adZNode = ADOPTION_ADS_ROOT_ZNODE + "/" + partitionToGiveOut.getPartitionFullNameWithBrokerId();
    logger.debug("Posting Ad for {}", adZNode);
    //create an ephemeral ad post
    client.create().withMode(CreateMode.EPHEMERAL).forPath(adZNode, AD_POSTING_TEXT.getBytes());
    long adPostTime = System.currentTimeMillis();
    logger.debug("Ad {} created at {}", adZNode, adPostTime);
    while (new String(client.getData().forPath(adZNode)).equals(AD_POSTING_TEXT)
            && System.currentTimeMillis() - adPostTime < AD_EXPIRY_MS) {
        logger.debug("Ad {} is active. Sleeping 1 min", adZNode);
        Thread.sleep(60000);
    }

    if (!new String(client.getData().forPath(adZNode)).equals(AD_POSTING_TEXT)) {
        logger.debug("Partition {} got adopted", adZNode);
    } else {
        logger.debug("Expired the Ad for {}", adZNode);
    }

    //Someone has adopted this partition, or the Ad needs to expire. Delete the Ad
    logger.debug("Deleting Ad node {}", adZNode);
    client.delete().forPath(adZNode);
}

From source file:ai.grakn.engine.backgroundtasks.distributed.TaskRunner.java

License:Open Source License

private void registerAsRunning() throws Exception {
    if (zkStorage.connection().checkExists().forPath(RUNNERS_WATCH + "/" + engineID) == null) {
        zkStorage.connection().create().creatingParentContainersIfNeeded().withMode(CreateMode.EPHEMERAL)
                .forPath(RUNNERS_WATCH + "/" + engineID);
    }//  w  ww.j a  v a  2 s. c o  m

    if (zkStorage.connection().checkExists().forPath(RUNNERS_STATE + "/" + engineID) == null) {
        zkStorage.connection().create().creatingParentContainersIfNeeded()
                .forPath(RUNNERS_STATE + "/" + engineID);
    }

    LOG.debug("Registered TaskRunner");
}

From source file:ai.grakn.engine.tasks.manager.multiqueue.MultiQueueTaskRunner.java

License:Open Source License

private void registerAsRunning() {
    try {/*from  w w w  . j  av a  2 s  .c o m*/
        if (connection.connection().checkExists()
                .forPath(format(SINGLE_ENGINE_WATCH_PATH, engineId.value())) == null) {
            connection.connection().create().creatingParentContainersIfNeeded().withMode(CreateMode.EPHEMERAL)
                    .forPath(format(SINGLE_ENGINE_WATCH_PATH, engineId.value()));
        }
    } catch (RuntimeException e) {
        throw e;
    } catch (Exception exception) {
        throw new RuntimeException("Could not create Zookeeper paths in TaskRunner");
    }

    LOG.debug("Registered TaskRunner");
}

From source file:ai.grakn.engine.tasks.manager.singlequeue.SingleQueueTaskManager.java

License:Open Source License

/**
 * Register this instance of Engine in Zookeeper to monitor its status
 *
 * @param engineId identifier of this instance of engine, which will be registered in Zookeeper
 * @param zookeeper connection to zookeeper
 * @throws Exception when there is an issue contacting or writing to zookeeper
 *///w  ww .  j a v a2  s . c  om
private void registerSelfForFailover(EngineID engineId, ZookeeperConnection zookeeper) throws Exception {
    zookeeper.connection().create().creatingParentContainersIfNeeded().withMode(CreateMode.EPHEMERAL)
            .forPath(format(SINGLE_ENGINE_WATCH_PATH, engineId.value()));
}

From source file:ai.grakn.test.engine.tasks.manager.multiqueue.TaskFailoverTest.java

License:Open Source License

private void registerFakeEngine(EngineID id) throws Exception {
    if (connection.connection().checkExists().forPath(format(SINGLE_ENGINE_WATCH_PATH, id.value())) == null) {
        connection.connection().create().creatingParentContainersIfNeeded().withMode(CreateMode.EPHEMERAL)
                .forPath(format(SINGLE_ENGINE_WATCH_PATH, id.value()));
    }/*from   w  ww .j a  v a2s . c  o m*/
    assertNotNull(connection.connection().checkExists().forPath(format(SINGLE_ENGINE_WATCH_PATH, id.value())));
}

From source file:alluxio.master.PrimarySelectorClient.java

License:Apache License

@Override
public void takeLeadership(CuratorFramework client) throws Exception {
    setState(State.PRIMARY);/*from www . ja va2 s  .c o  m*/
    if (client.checkExists().forPath(mLeaderFolder + mName) != null) {
        LOG.info("Deleting zk path: {}{}", mLeaderFolder, mName);
        client.delete().forPath(mLeaderFolder + mName);
    }
    LOG.info("Creating zk path: {}{}", mLeaderFolder, mName);
    client.create().creatingParentsIfNeeded().withMode(CreateMode.EPHEMERAL).forPath(mLeaderFolder + mName);
    LOG.info("{} is now the leader.", mName);
    try {
        waitForState(State.SECONDARY);
    } finally {
        LOG.warn("{} relinquishing leadership.", mName);
        LOG.info("The current leader is {}", mLeaderSelector.getLeader().getId());
        LOG.info("All participants: {}", mLeaderSelector.getParticipants());
        client.delete().forPath(mLeaderFolder + mName);
    }
}

From source file:blazingcache.zookeeper.ZKClusterManager.java

License:Apache License

/**
 * Let cache server compete for cluster leadership.
 *///  w  w w  . j a  v  a  2s.  co m
public void requestLeadership() {
    zk.create(leaderpath, localhostdata, ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.EPHEMERAL,
            masterCreateCallback, null);
}

From source file:br.unb.cic.bionimbuz.services.RepositoryService.java

/**
 * @param resource//from  ww  w  .  j av  a 2s.c  o  m
 *            Resource to be added
 */
public void addPeerToZookeeper(PluginInfo resource) {
    this.cms.createZNode(CreateMode.PERSISTENT, Path.NODE_PEER.getFullPath(resource.getId()),
            resource.toString());
    this.cms.createZNode(CreateMode.EPHEMERAL, Path.STATUS.getFullPath(resource.getId()), null);
    this.cms.createZNode(CreateMode.PERSISTENT, Path.SCHED.getFullPath(resource.getId()), null);
    this.cms.createZNode(CreateMode.PERSISTENT, Path.TASKS.getFullPath(resource.getId()), null);
}

From source file:ch.ethz.globis.distindex.orchestration.ZKClusterService.java

License:Open Source License

private void initSizeCounter(String hostId) throws Exception {
    if (sizes.containsKey(hostId)) {
        throw new IllegalStateException("Host size should not be initialized");
    }//ww w.  ja  v  a2 s  .  c om
    int value = 0;
    sizes.put(hostId, value);
    String path = sizePath(hostId);
    client.create().withMode(CreateMode.EPHEMERAL).forPath(path, intToByte(value));
}

From source file:ch.usi.da.paxos.old.Proposer.java

License:Open Source License

private void init() throws IOException {
    setLeader(true); // initially everybody is a leader

    // register the leader selection watcher
    try {/* w w w  .  ja v a 2 s  .c om*/
        if (zoo.exists(path, false) == null) {
            zoo.create(path, null, Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);
        }
        zoo.getChildren(path, true); // start watching
        zoo.create(path + "/" + this.getID(), null, Ids.OPEN_ACL_UNSAFE, CreateMode.EPHEMERAL);
    } catch (Exception e) {
        //e.printStackTrace();
        System.out.println("Running without zookeeper. So no leader election!");
    }
}