Example usage for org.apache.zookeeper Watcher Watcher

Introduction

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

Prototype

Watcher

Source Link

Usage

From source file:com.greplin.zookeeper.RobustZooKeeperTest.java

License:Apache License

private void checkNoRemainingLocks(String lockName) throws IOException, InterruptedException, KeeperException {
    ZooKeeper verifier = new ZooKeeper("localhost:" + ZK_PORT, Integer.MAX_VALUE, new Watcher() {
        @Override//from w w  w. j a v  a 2s  . c om
        public void process(WatchedEvent event) {
            // no-op watcher
        }
    });
    List<String> children = verifier.getChildren(RobustZooKeeper.LOCK_NODE_PREFIX + lockName, false);
    Assert.assertEquals(0, children.size());
}

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From source file:com.griddynamics.jagger.coordinator.zookeeper.DefaultZNodeLock.java

License:Open Source License

@Override
public void lock() {
    while (true) {
        ZNode node = lockDir().createChild(znode().ephemeralSequential());

        final String currentNodeName = node.getShortPath();
        int currentFlag = Integer.valueOf(currentNodeName);

        final List<ZNode> children = lockDir().children();
        int lowestNodeVal = Integer.MAX_VALUE;
        int nextNodeFlag = -1;
        String nextNodePath = null;

        for (ZNode child : children) {
            String childPath = child.getShortPath();
            int childFlag = Integer.valueOf(childPath);

            if (childFlag < lowestNodeVal) {
                lowestNodeVal = childFlag;
            }/*from w w w  .  j  ava 2 s.  co  m*/

            if (childFlag < currentFlag && childFlag > nextNodeFlag) {
                nextNodeFlag = childFlag;
                nextNodePath = childPath;
            }
        }

        if (currentFlag == lowestNodeVal) {
            lockNode = node;
            break;
        }

        final CountDownLatch signal = new CountDownLatch(1);
        boolean hasChild = lockDir().hasChild(nextNodePath, new Watcher() {
            @Override
            public void process(WatchedEvent event) {
                signal.countDown();
            }
        });

        if (hasChild) {
            lockNode = node;

            try {
                signal.await();
                break;
            } catch (InterruptedException e) {
                throw new RuntimeException(e);
            }
        }

        node.remove();
    }
}

---

From source file:com.griddynamics.jagger.coordinator.zookeeper.ZookeeperCoordinator.java

License:Open Source License

@Override
public void registerNode(NodeContext nodeContext, Set<Worker> workers, final StatusChangeListener listener)
        throws CoordinatorException {
    log.info("Going to register node {} with {} workers", nodeContext.getId(), workers.size());

    ZNode typeNode = rootNode.child(CoordinationUtil.nodeNameOf(nodeContext.getId().getType()));
    ZNode node = typeNode.createChild(znode().withPath(nodeContext.getId().getIdentifier()));

    Set<CommandExecutor<?, ?>> executors = Sets.newHashSet();
    Set<Qualifier<?>> qualifiers = Sets.newHashSet();

    for (Worker worker : workers) {
        for (CommandExecutor<?, ?> executor : worker.getExecutors()) {
            Qualifier<?> qualifier = executor.getQualifier();
            if (qualifiers.contains(qualifier)) {
                throw new CoordinatorException(
                        "Executor for qualifier " + qualifier + " is already registered");
            }//from w  ww  . j  a  v  a  2  s.c  o m

            executors.add(executor);
        }
    }

    for (CommandExecutor<?, ?> executor : executors) {
        registerExecutor(nodeContext, executor, node);
    }

    rootNode.addNodeWatcher(new Watcher() {
        @Override
        public void process(WatchedEvent event) {
            if (event.getState() == Event.KeeperState.Disconnected) {
                listener.onCoordinatorDisconnected();
            }

            if (event.getState() == Event.KeeperState.SyncConnected) {
                listener.onCoordinatorConnected();
            }
        }
    });

    ZNode statuses = rootNode.child(CoordinationUtil.STATUSES_NODE_NAME);

    statuses.createChild(znode().ephemeralSequential().withDataObject(nodeContext.getId()));

    Lock lock = new ReentrantLock();

    lock.lock();
    try {
        Collection<NodeId> nodeIds = Sets.newHashSet();
        StatusWatcher statusWatcher = new StatusWatcher(statuses, lock, nodeIds, listener);
        List<ZNode> nodes = statuses.children(statusWatcher);
        for (ZNode zNode : nodes) {
            nodeIds.add(zNode.getObject(NodeId.class));
        }
    } finally {
        lock.unlock();
    }

    node.createChild(znode().withPath(CoordinationUtil.AVAILABLE_NODE_NAME));
}

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From source file:com.griddynamics.jagger.coordinator.zookeeper.ZookeeperCoordinator.java

License:Open Source License

private <C extends Command<R>, R extends Serializable> void registerExecutor(final NodeContext nodeContext,
        final CommandExecutor<C, R> executor, ZNode node) {
    final ZNode executorNode = node.createChild(znode().withPath(nodeNameOf(executor.getQualifier())));
    final ZNode queueNode = executorNode.createChild(znode().withPath("queue"));
    executorNode.createChild(znode().withPath("result"));

    log.debug("Created znodes for executor {}", executorNode.getPath());

    queueNode.addChildrenWatcher(new Watcher() {
        @Override// w  w  w .j a  v  a 2 s  .c  o m
        public void process(WatchedEvent event) {
            if (event.getType() != Event.EventType.NodeChildrenChanged) {
                return;
            }

            synchronized (lock) {
                if (log.isDebugEnabled()) {
                    log.debug("Children changed {} event type {}", queueNode.getPath(), event.getType());
                }

                List<QueueEntry<C, R>> entries = getEntries(queueNode, this);

                for (final QueueEntry<C, R> entry : entries) {
                    Runnable run = new Runnable() {

                        @Override
                        public void run() {
                            executeCommand(executor, executorNode, entry, nodeContext);
                        }
                    };

                    ZookeeperCoordinator.this.executor.execute(run);
                }
            }

        }
    });
}

---

From source file:com.griddynamics.jagger.coordinator.zookeeper.ZooKeeperFactory.java

License:Open Source License

public IZookeeper create() {
    final CountDownLatch connectedSignal = new CountDownLatch(1);
    IZookeeper zooKeeper = null;//from  www  . ja v a 2 s  .c  om

    try {
        zooKeeper = new DefaultZookeeper(connectString, sessionTimeout, new Watcher() {
            @Override
            public void process(WatchedEvent event) {
                if (event.getState() == Event.KeeperState.SyncConnected) {
                    connectedSignal.countDown();
                }
            }
        }, reconnectPeriod);

        connectedSignal.await();

    } catch (Exception e) {
        throw new ZooException(e);
    }

    return zooKeeper;
}

---

From source file:com.griddynamics.jagger.coordinator.zookeeper.ZooKeeperRemoteExecutor.java

License:Open Source License

@Override
public <C extends Command<R>, R extends Serializable> void run(final C command,
        final NodeCommandExecutionListener<C> listener, final AsyncCallback<R> callback) {
    ZNode commandNode = rootNode.child(nodeId.getType().name().toLowerCase()).child(nodeId.getIdentifier())
            .child(command.getClass().getName());
    ZNode queueNode = commandNode.child("queue");
    ZNode resultNode = commandNode.child("result");

    final ZNode outputNode = resultNode.createChild(znode().persistentSequential());

    outputNode.addNodeWatcher(new Watcher() {
        @Override/*from  w  w  w .j ava 2s.  c  om*/
        public void process(WatchedEvent event) {
            log.debug("command {} execution done", command);
            CommandExecutionResult result = outputNode.getObject(CommandExecutionResult.class);
            switch (result.getStatus()) {
            case SUCCEEDED:
                log.debug("success");
                callback.onSuccess((R) result.getResult());
                break;
            case FAILED:
                Throwable e = result.getException();
                log.error("fail", e);
                callback.onFailure(e);
                break;
            default:
                throw new IllegalStateException("Unknown status");
            }

            outputNode.removeWithChildren();

        }
    });
    queueNode.createChild(znode().persistentSequential()
            .withDataObject(new QueueEntry<C, R>(command, listener, outputNode.getPath())));
    log.debug("command {} is ready to be executed", command);
}

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From source file:com.gxl.shark.resources.conn.ZookeeperConnectionManager.java

License:Apache License

/**
 * zookeeper//from   ww w .  ja v a  2 s  .  c  om
 * 
 * @author JohnGao
 */
private void connection() {
    try {
        zk_client = new ZooKeeper(zk_address, zk_session_timeout, new Watcher() {
            @Override
            public void process(WatchedEvent event) {
                final KeeperState STATE = event.getState();
                final String VALUE = "zookeeper?[" + zk_address + "]";
                switch (STATE) {
                case SyncConnected:
                    countDownLatch.countDown();
                    logger.info(VALUE + "?");
                    break;
                case Disconnected:
                    logger.warn(VALUE + "?");
                    break;
                case Expired:
                    logger.error(VALUE + "??");
                    break;
                case AuthFailed:
                    logger.error(VALUE + "?ACL?");
                default:
                    break;
                }
            }
        });
        countDownLatch.await();
        /* ?? */
        registerNode.register(zk_client, nodePath);
    } catch (IOException e) {
        throw new ResourceException("zookeeper?[" + e.toString() + "]");
    } catch (InterruptedException e) {
        e.printStackTrace();
    }
}

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From source file:com.gxl.test.shark.resource.zkSetData.java

License:Apache License

public @Test void testSetData() {
    try (BufferedReader reader = new BufferedReader(new FileReader("c:/shark-datasource.xml"))) {
        StringBuffer str = new StringBuffer();
        String value = "";
        while (null != (value = reader.readLine()))
            str.append(value);/*from   w  w w  . ja va 2  s  .  c om*/
        final CountDownLatch countDownLatch = new CountDownLatch(1);
        ZooKeeper zk_client = new ZooKeeper(
                "120.25.58.116:2181,120.25.58.116:2182,120.25.58.116:2183,120.25.58.116:2184", 30000,
                new Watcher() {
                    @Override
                    public void process(WatchedEvent event) {
                        final KeeperState STATE = event.getState();
                        switch (STATE) {
                        case SyncConnected:
                            countDownLatch.countDown();
                            logger.info("?zookeeper?");
                            break;
                        case Disconnected:
                            logger.warn("zookeeper?");
                            break;
                        case Expired:
                            logger.error("session?...");
                            break;
                        case AuthFailed:
                            logger.error("ACL?...");
                        default:
                            break;
                        }
                    }
                });
        countDownLatch.await();
        zk_client.setData("/info/datasource", str.toString().getBytes(), -1);
        logger.info("insert success");
    } catch (Exception e) {
        logger.error("insert fail", e);
    }
}

---

From source file:com.gxl.zk.ZKConnectionManager.java

License:Apache License

/**
 * zookeeper/*  www .  j  a v  a2  s.c o  m*/
 * 
 * @author gaoxianglong
 * 
 * @throws ConnectionException
 * 
 * @return void
 */
private void connection() {
    countDownLatch = new CountDownLatch(1);
    try {
        zk_client = new ZooKeeper(address, zk_session_timeout, new Watcher() {
            @Override
            public void process(WatchedEvent event) {
                final KeeperState STATE = event.getState();
                switch (STATE) {
                case SyncConnected:
                    countDownLatch.countDown();
                    logger.info("connection zookeeper success");
                    break;
                case Disconnected:
                    logger.warn("zookeeper connection is disconnected");
                    break;
                case Expired:
                    logger.error("zookeeper session expired");
                    break;
                case AuthFailed:
                    logger.error("authentication failure");
                default:
                    break;
                }
            }
        });
        countDownLatch.await();
        String samplingRate = null;
        /* ?? */
        if (null == zk_client.exists("/tracing", false)) {
            zk_client.create("/tracing", new byte[0], Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);
        }
        /* ?znode? */
        if (null != zk_client.exists(samplingRate_path, false)) {
            samplingRate = new String(zk_client.getData(samplingRate_path,
                    new SamplingRateWatcher(zk_client, samplingRate_path), null));
        } else {
            logger.warn("-->" + samplingRate_path + "?,");
            /* ?1/1024 */
            zk_client.create(samplingRate_path, "1024".getBytes(), Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);
            samplingRate = new String(zk_client.getData(samplingRate_path,
                    new SamplingRateWatcher(zk_client, samplingRate_path), null));
        }
        /*  */
        TraceFilter.samplingNum = Integer.parseInt(samplingRate);
    } catch (Exception e) {
        logger.error("error", e);
    }
}

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From source file:com.iquanwai.confucius.biz.util.zk.RobustZooKeeper.java

License:Apache License

private void lockRecipeStepTwo(final String fullPath, final String relativePath, final String lockName,
        final Runnable action) throws IOException, InterruptedException, KeeperException {

    log.info("Client " + this.clientNumber + " at start of lockRecipeStepTwo with relativePath = "
            + relativePath);/*  ww w  .  j a v  a2 s  .co  m*/
    if (this.shutdown.get()) {
        log.warn("Client " + this.clientNumber + " is shutdown - so I'm going to give up my attempt to lock");
        return;
    }

    // step 2
    final List<String> children = getClient().getChildren(getLockParent(lockName), false);
    assert children.size() > 0; // at the ver least, my node should be there.
    Collections.sort(children);

    // step 3
    if (relativePath.equals(children.get(0))) {
        log.info("Client " + this.clientNumber + " has the lowest number lock attempt (" + relativePath
                + "), so it holds the lock");
        try {
            action.run();
        } finally {
            log.info("Client " + this.clientNumber + " finished doing my work with " + relativePath
                    + ", so I'm giving up the lock.");
            try {
                getClient().delete(fullPath, -1);
            } catch (KeeperException.NoNodeException e) {
                log.warn("After I finished running an action with lock " + lockName + " the actions lock node ("
                        + fullPath + ") no longer exists. This should only happen if you manually deleted "
                        + fullPath + " or there was an underlying network failure, and we had to reconnect");
            }
        }
        return;
    }

    // step 4
    final int indexOfNodeBefore = children.indexOf(relativePath) - 1;
    if (indexOfNodeBefore < 0) {
        throw new IllegalStateException(
                "indexOfNodeBefore is " + indexOfNodeBefore + ", and children are: " + children);
    }

    final String nodeBeforeMine = children.get(indexOfNodeBefore);
    log.info("Client " + this.clientNumber + "  (at " + relativePath
            + ") is setting a watch on the node before me (" + nodeBeforeMine + ")");
    final Stat exists = getClient().exists(getLockParent(lockName) + "/" + nodeBeforeMine, new Watcher() {
        @Override
        public void process(WatchedEvent event) {
            try {
                log.info("Client " + RobustZooKeeper.this.clientNumber + ", when watching " + nodeBeforeMine
                        + ", got notified: " + event);
                lockRecipeStepTwo(fullPath, relativePath, lockName, action);
            } catch (Exception e) {
                log.warn("Unable to execute action with lock " + lockName, e);
            }
        }
    });

    // step 5
    if (exists == null) {
        log.info("Client " + this.clientNumber + " expected " + nodeBeforeMine
                + " to exist - but it doesn't so re-running step 2");
        lockRecipeStepTwo(fullPath, relativePath, lockName, action);
    }
}

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