Example usage for org.apache.zookeeper.recipes.lock WriteLock WriteLock

Introduction

In this page you can find the example usage for org.apache.zookeeper.recipes.lock WriteLock WriteLock.

Prototype

public WriteLock(ZooKeeper zookeeper, String dir, List<ACL> acl) 

Source Link

Document

zookeeper contructor for writelock.

Usage

From source file:com.jointhegrid.ironcount.manager.WorkloadManager.java

License:Apache License

public void considerStartingWorkload(Workload w) {
    logger.debug("considert starting " + w);
    if (w.active == false) {
        logger.debug(w.name + " is non active");
        return;//from   w  ww  . ja v  a  2  s .  c  o m
    }
    WriteLock l = null;
    try {
        l = new WriteLock(zk, "/ironcount/workloads/" + w.name, null);
        l.lock();
        List<String> children = zk.getChildren("/ironcount/workloads/" + w.name, false);
        if (children.size() <= w.maxWorkers) {
            WorkerThread wt = new WorkerThread(this, w);
            this.executor.submit(wt);
            this.workerThreads.put(wt, new Object());
            logger.debug("Started worker thread " + wt + " " + w);
        }
    } catch (KeeperException ex) {
        throw new RuntimeException(ex);
    } catch (InterruptedException ex) {
        throw new RuntimeException(ex);
    } catch (Throwable t) {
        t.printStackTrace(System.err);
        logger.error(t);
        throw new RuntimeException(t);
    } finally {
        l.unlock();
    }
}

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From source file:com.wms.studio.lock.LocalZookeeperLock.java

License:Apache License

public LocalZookeeperLock(ZooKeeper zk, String root, String lockPath) {
    path = formatPath(root, lockPath);/*from  w  w  w.  ja va 2  s . co m*/
    // ??key
    jvmLock = JVM_LOCAL_LOCKS.get(path);
    if (jvmLock == null) {
        jvmLock = new ReentrantLock();
        JVM_LOCAL_LOCKS.put(path, jvmLock);
    }
    lock = new WriteLock(zk, path, null);
}

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From source file:io.teknek.daemon.TeknekDaemon.java

License:Apache License

private void considerStarting(String child) throws WorkerDaoException {
    Plan plan = WorkerDao.findPlanByName(reKeeper.getZooKeeper(), child);
    if (plan == null) {
        logger.warn(String.format("Did not find a valid plan under node name %s", child));
        return;//from w ww  . j  a va2 s  .  c o  m
    }
    if (!child.equals(plan.getName())) {
        logger.warn(String.format("Node name %s is not the same is the json value %s will not start", child,
                plan.getName()));
        return;
    }
    List<String> workerUuidsWorkingOnPlan = WorkerDao.findWorkersWorkingOnPlan(reKeeper.getZooKeeper(), plan);
    if (alreadyAtMaxWorkersPerNode(plan, workerUuidsWorkingOnPlan, workerThreads.get(plan))) {
        return;
    }
    if (!isPlanSane(plan)) {
        return;
    }
    logger.debug("trying to acqure lock on " + WorkerDao.LOCKS_ZK + "/" + plan.getName());
    WorkerDao.maybeCreatePlanLockDir(reKeeper.getZooKeeper(), plan);
    final CountDownLatch c = new CountDownLatch(1);
    WriteLock l = new WriteLock(reKeeper.getZooKeeper(), WorkerDao.LOCKS_ZK + "/" + plan.getName(), null);
    l.setLockListener(new LockListener() {

        @Override
        public void lockAcquired() {
            logger.debug(myId + " counting down");
            c.countDown();
        }

        @Override
        public void lockReleased() {
            logger.debug(myId + " released");
        }

    });
    boolean hasLatch = false;
    try {
        boolean gotLock = l.lock();
        if (!gotLock) {
            logger.debug("did not get lock");
            return;
        }
        hasLatch = c.await(3000, TimeUnit.MILLISECONDS);
        if (hasLatch) {
            plan = WorkerDao.findPlanByName(reKeeper.getZooKeeper(), child);
            if (plan.isDisabled()) {
                logger.debug("disabled " + plan.getName());
                return;
            }
            List<String> workerUuids = WorkerDao.findWorkersWorkingOnPlan(reKeeper.getZooKeeper(), plan);
            if (workerUuids.size() >= plan.getMaxWorkers()) {
                logger.debug("already running max children:" + workerUuids.size() + " planmax:"
                        + plan.getMaxWorkers() + " running:" + workerUuids);
                return;
            }
            logger.debug("starting worker");
            try {
                Worker worker = new Worker(plan, workerUuids, this);
                worker.init();
                worker.start();
                addWorkerToList(plan, worker);
            } catch (RuntimeException e) {
                throw new WorkerStartException(e);
            }
        }
    } catch (KeeperException | InterruptedException | WorkerDaoException | WorkerStartException e) {
        logger.warn("getting lock", e);
    } finally {
        try {
            l.unlock();
        } catch (RuntimeException ex) {
            logger.warn("Unable to unlock/cleanup. hadlock?" + hasLatch, ex);
        }
    }
}

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