Example usage for org.apache.zookeeper ZooKeeper getData

List of usage examples for org.apache.zookeeper ZooKeeper getData

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Introduction

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

Prototype

public void getData(String path, boolean watch, DataCallback cb, Object ctx)

Source Link

Document

The asynchronous version of getData.

Usage

From source file:com.nesscomputing.service.discovery.client.internal.ServiceDiscoveryReader.java

License:Apache License

@Override
void visit(final List<String> childNodes, final ZooKeeper zookeeper, final long tick)
        throws InterruptedException {
    final Map<String, List<ServiceInformation>> serviceMap = new HashMap<String, List<ServiceInformation>>();

    if (!childNodes.isEmpty()) {
        final List<ServiceInformation> rawServices = new ArrayList<ServiceInformation>(childNodes.size());
        final CountDownLatch latch = new CountDownLatch(childNodes.size());

        final long now = System.nanoTime();

        for (final String child : childNodes) {

            final String childPath = getNodePath(child);

            if (badNodes.containsKey(childPath)) {
                final Long penaltyEndsTime = badNodes.get(childPath);
                if (penaltyEndsTime != null && penaltyEndsTime > now) {
                    // Decrement the countdown latch, because there will be no callback for this
                    // node.
                    latch.countDown();//from  w w  w  .  j  av a  2 s  .  c o m
                    // Ignore a bad node for a while.
                    continue;
                }
                LOG.info("Unmarking %s as a bad node!", childPath);
                badNodes.remove(childPath);
            }

            zookeeper.getData(childPath, false, new DataCallback() {
                @Override
                public void processResult(final int rc, final String path, final Object ctx, final byte[] data,
                        final Stat stat) {

                    ServiceInformation si = null;
                    try {
                        if (data != null && data.length > 0) {
                            si = objectMapper.readValue(data, ServiceInformation.class);
                            LOG.trace("%s contains %s", path, si);
                        } else {
                            // This can sometimes happen if a node that we want to inspect
                            // disappears between callback post and callback processing.
                            LOG.trace("Got callback but no data!");
                        }

                    } catch (IOException ioe) {
                        LOG.debug(ioe, "While deserializing %s", new String(data, Charsets.UTF_8));
                        LOG.info("Marking %s as a bad node!", path);
                        // Put a bad node into the penalty box.
                        badNodes.put(path, now + penaltyTime);
                    } finally {
                        synchronized (rawServices) {
                            if (si != null) {
                                rawServices.add(si);
                            }
                        }
                        latch.countDown();
                    }
                }
            }, null);
        }

        if (!latch.await(discoveryConfig.getZookeeperTimeout().getMillis(), TimeUnit.MILLISECONDS)) {
            LOG.warn("Timeout waiting for callbacks, some nodes were not parsed.");
        }

        // Make sure that even with late callbacks, this will not throw spurious ConcurrentModificationExceptions
        synchronized (rawServices) {
            for (final ServiceInformation si : rawServices) {
                List<ServiceInformation> services = serviceMap.get(si.getServiceName());
                if (services == null) {
                    services = new ArrayList<ServiceInformation>();
                    serviceMap.put(si.getServiceName(), services);
                }
                services.add(si);
            }
        }
    }

    Map<String, ConsistentRingGroup> serviceGroups = Maps.newHashMap();
    for (Map.Entry<String, List<ServiceInformation>> entry : serviceMap.entrySet()) {
        ConsistentRingGroup currentGroup = stateHolder.getState().get(entry.getKey());
        //Rebuilding a group is kind of expensive, so reuse the old group if it hasn't changed
        if (currentGroup != null
                && Sets.newHashSet(entry.getValue()).equals(Sets.newHashSet(currentGroup.getAll()))) {
            serviceGroups.put(entry.getKey(), currentGroup);
        } else {
            serviceGroups.put(entry.getKey(), new ConsistentRingGroup(entry.getValue()));
        }
    }
    stateHolder.setState(serviceGroups);
}

From source file:com.proofpoint.zookeeper.ZookeeperClient.java

License:Apache License

@Override
public DataAndStat getDataAndStat(final String path) throws Exception {
    if (inBackground) {
        RetryHandler.Call<Void> backgroundCall = new RetryHandler.Call<Void>() {
            @Override/*  w ww. j  a  va2  s.c om*/
            public Void call(ZooKeeper client, final RetryHandler<Void> retryHandler) throws Exception {
                if (overrideWatcher != null) {
                    client.getData(path, overrideWatcher, new RetryDataCallback(retryHandler), context);
                } else {
                    client.getData(path, watched, new RetryDataCallback(retryHandler), context);
                }
                return null;
            }
        };
        RetryHandler.makeAndStart(this, retryPolicy, backgroundCall);
        return null;
    }

    RetryHandler.Call<DataAndStat> backgroundCall = new RetryHandler.Call<DataAndStat>() {
        @Override
        public DataAndStat call(ZooKeeper client, RetryHandler<DataAndStat> dataAndStatRetryHandler)
                throws Exception {
            final Stat stat = new Stat();
            final byte[] data = (overrideWatcher != null) ? client.getData(path, overrideWatcher, stat)
                    : client.getData(path, watched, stat);
            return new DataAndStat() {
                @Override
                public Stat getStat() {
                    return stat;
                }

                @Override
                public byte[] getData() {
                    return data;
                }
            };
        }
    };
    return RetryHandler.makeAndStart(this, retryPolicy, backgroundCall);
}

From source file:com.twitter.distributedlog.lock.ZKSessionLock.java

License:Apache License

/**
 * Get client id and its ephemeral owner.
 *
 * @param zkClient//from  w  w w .ja v  a 2  s .  c  om
 *          zookeeper client
 * @param lockPath
 *          lock path
 * @param nodeName
 *          node name
 * @return client id and its ephemeral owner.
 */
static Future<Pair<String, Long>> asyncParseClientID(ZooKeeper zkClient, String lockPath, String nodeName) {
    String[] parts = nodeName.split("_");
    // member_<clientid>_s<owner_session>_
    if (4 == parts.length && parts[2].startsWith("s")) {
        long sessionOwner = Long.parseLong(parts[2].substring(1));
        String clientId;
        try {
            clientId = URLDecoder.decode(parts[1], UTF_8.name());
            return Future.value(Pair.of(clientId, sessionOwner));
        } catch (UnsupportedEncodingException e) {
            // if failed to parse client id, we have to get client id by zookeeper#getData.
        }
    }
    final Promise<Pair<String, Long>> promise = new Promise<Pair<String, Long>>();
    zkClient.getData(lockPath + "/" + nodeName, false, new AsyncCallback.DataCallback() {
        @Override
        public void processResult(int rc, String path, Object ctx, byte[] data, Stat stat) {
            if (KeeperException.Code.OK.intValue() != rc) {
                promise.setException(KeeperException.create(KeeperException.Code.get(rc)));
            } else {
                promise.setValue(Pair.of(deserializeClientId(data), stat.getEphemeralOwner()));
            }
        }
    }, null);
    return promise;
}

From source file:com.twitter.distributedlog.util.Utils.java

License:Apache License

/**
 * Retrieve data from zookeeper <code>path</code>.
 *
 * @param path/*from w w  w  .jav  a2s  . com*/
 *          zookeeper path to retrieve data
 * @param watch
 *          whether to watch the path
 * @return future representing the versioned value. null version or null value means path doesn't exist.
 */
public static Future<Versioned<byte[]>> zkGetData(ZooKeeper zk, String path, boolean watch) {
    final Promise<Versioned<byte[]>> promise = new Promise<Versioned<byte[]>>();
    zk.getData(path, watch, new AsyncCallback.DataCallback() {
        @Override
        public void processResult(int rc, String path, Object ctx, byte[] data, Stat stat) {
            if (KeeperException.Code.OK.intValue() == rc) {
                if (null == stat) {
                    promise.setValue(new Versioned<byte[]>(null, null));
                } else {
                    promise.setValue(new Versioned<byte[]>(data, new ZkVersion(stat.getVersion())));
                }
            } else if (KeeperException.Code.NONODE.intValue() == rc) {
                promise.setValue(new Versioned<byte[]>(null, null));
            } else {
                promise.setException(KeeperException.create(KeeperException.Code.get(rc)));
            }
        }
    }, null);
    return promise;
}

From source file:org.apache.bookkeeper.zookeeper.BkZooKeeperClient.java

License:Apache License

@Override
public void getData(final String path, final Watcher watcher, final DataCallback cb, final Object context) {
    final Runnable proc = new ZkRetryRunnable(operationRetryPolicy, rateLimiter, getStats) {

        final DataCallback dataCb = new DataCallback() {

            @Override/*from   w  w w .  j a va  2 s  .  co  m*/
            public void processResult(int rc, String path, Object ctx, byte[] data, Stat stat) {
                BkZooWorker worker = (BkZooWorker) ctx;
                if (allowRetry(worker, rc)) {
                    backOffAndRetry(that, worker.nextRetryWaitTime());
                } else {
                    cb.processResult(rc, path, context, data, stat);
                }
            }

        };

        @Override
        void zkRun() {
            ZooKeeper zkHandle = zk.get();
            if (null == zkHandle) {
                BkZooKeeperClient.super.getData(path, watcher, dataCb, worker);
            } else {
                zkHandle.getData(path, watcher, dataCb, worker);
            }
        }

        @Override
        public String toString() {
            return String.format("getData (%s, watcher = %s)", path, watcher);
        }
    };
    // execute it immediately
    proc.run();
}

From source file:org.apache.bookkeeper.zookeeper.BkZooKeeperClient.java

License:Apache License

@Override
public void getData(final String path, final boolean watch, final DataCallback cb, final Object context) {
    final Runnable proc = new ZkRetryRunnable(operationRetryPolicy, rateLimiter, getStats) {

        final DataCallback dataCb = new DataCallback() {

            @Override//from   www. j a v a  2  s .  co  m
            public void processResult(int rc, String path, Object ctx, byte[] data, Stat stat) {
                BkZooWorker worker = (BkZooWorker) ctx;
                if (allowRetry(worker, rc)) {
                    backOffAndRetry(that, worker.nextRetryWaitTime());
                } else {
                    cb.processResult(rc, path, context, data, stat);
                }
            }

        };

        @Override
        void zkRun() {
            ZooKeeper zkHandle = zk.get();
            if (null == zkHandle) {
                BkZooKeeperClient.super.getData(path, watch, dataCb, worker);
            } else {
                zkHandle.getData(path, watch, dataCb, worker);
            }
        }

        @Override
        public String toString() {
            return String.format("getData (%s, watcher = %s)", path, watch);
        }
    };
    // execute it immediately
    proc.run();
}

From source file:org.apache.bookkeeper.zookeeper.ZooKeeperClient.java

License:Apache License

@Override
public void getData(final String path, final Watcher watcher, final DataCallback cb, final Object context) {
    final Runnable proc = new ZkRetryRunnable(operationRetryPolicy, rateLimiter, getStats) {

        final DataCallback dataCb = new DataCallback() {

            @Override//from   www  .ja  v a  2  s .c  om
            public void processResult(int rc, String path, Object ctx, byte[] data, Stat stat) {
                ZooWorker worker = (ZooWorker) ctx;
                if (allowRetry(worker, rc)) {
                    backOffAndRetry(that, worker.nextRetryWaitTime());
                } else {
                    cb.processResult(rc, path, context, data, stat);
                }
            }

        };

        @Override
        void zkRun() {
            ZooKeeper zkHandle = zk.get();
            if (null == zkHandle) {
                ZooKeeperClient.super.getData(path, watcher, dataCb, worker);
            } else {
                zkHandle.getData(path, watcher, dataCb, worker);
            }
        }

        @Override
        public String toString() {
            return String.format("getData (%s, watcher = %s)", path, watcher);
        }
    };
    // execute it immediately
    proc.run();
}

From source file:org.apache.bookkeeper.zookeeper.ZooKeeperClient.java

License:Apache License

@Override
public void getData(final String path, final boolean watch, final DataCallback cb, final Object context) {
    final Runnable proc = new ZkRetryRunnable(operationRetryPolicy, rateLimiter, getStats) {

        final DataCallback dataCb = new DataCallback() {

            @Override//from   w  w w. j  a  va 2s.  c  om
            public void processResult(int rc, String path, Object ctx, byte[] data, Stat stat) {
                ZooWorker worker = (ZooWorker) ctx;
                if (allowRetry(worker, rc)) {
                    backOffAndRetry(that, worker.nextRetryWaitTime());
                } else {
                    cb.processResult(rc, path, context, data, stat);
                }
            }

        };

        @Override
        void zkRun() {
            ZooKeeper zkHandle = zk.get();
            if (null == zkHandle) {
                ZooKeeperClient.super.getData(path, watch, dataCb, worker);
            } else {
                zkHandle.getData(path, watch, dataCb, worker);
            }
        }

        @Override
        public String toString() {
            return String.format("getData (%s, watcher = %s)", path, watch);
        }
    };
    // execute it immediately
    proc.run();
}

From source file:org.apache.distributedlog.lock.ZKSessionLock.java

License:Apache License

/**
 * Get client id and its ephemeral owner.
 *
 * @param zkClient// w  w  w  .jav  a 2s. c o  m
 *          zookeeper client
 * @param lockPath
 *          lock path
 * @param nodeName
 *          node name
 * @return client id and its ephemeral owner.
 */
static CompletableFuture<Pair<String, Long>> asyncParseClientID(ZooKeeper zkClient, String lockPath,
        String nodeName) {
    String[] parts = nodeName.split("_");
    // member_<clientid>_s<owner_session>_
    if (4 == parts.length && parts[2].startsWith("s")) {
        long sessionOwner = Long.parseLong(parts[2].substring(1));
        String clientId;
        try {
            clientId = URLDecoder.decode(parts[1], UTF_8.name());
            return FutureUtils.value(Pair.of(clientId, sessionOwner));
        } catch (UnsupportedEncodingException e) {
            // if failed to parse client id, we have to get client id by zookeeper#getData.
        }
    }
    final CompletableFuture<Pair<String, Long>> promise = new CompletableFuture<Pair<String, Long>>();
    zkClient.getData(lockPath + "/" + nodeName, false, new AsyncCallback.DataCallback() {
        @Override
        public void processResult(int rc, String path, Object ctx, byte[] data, Stat stat) {
            if (KeeperException.Code.OK.intValue() != rc) {
                promise.completeExceptionally(KeeperException.create(KeeperException.Code.get(rc)));
            } else {
                promise.complete(Pair.of(deserializeClientId(data), stat.getEphemeralOwner()));
            }
        }
    }, null);
    return promise;
}

From source file:org.apache.distributedlog.util.Utils.java

License:Apache License

/**
 * Retrieve data from zookeeper <code>path</code>.
 *
 * @param path//from  w  w w.j  a  va  2s .co  m
 *          zookeeper path to retrieve data
 * @param watch
 *          whether to watch the path
 * @return future representing the versioned value. null version or null value means path doesn't exist.
 */
public static CompletableFuture<Versioned<byte[]>> zkGetData(ZooKeeper zk, String path, boolean watch) {
    final CompletableFuture<Versioned<byte[]>> promise = new CompletableFuture<Versioned<byte[]>>();
    zk.getData(path, watch, new AsyncCallback.DataCallback() {
        @Override
        public void processResult(int rc, String path, Object ctx, byte[] data, Stat stat) {
            if (KeeperException.Code.OK.intValue() == rc) {
                if (null == stat) {
                    promise.complete(new Versioned<byte[]>(null, null));
                } else {
                    promise.complete(new Versioned<byte[]>(data, new LongVersion(stat.getVersion())));
                }
            } else if (KeeperException.Code.NONODE.intValue() == rc) {
                promise.complete(new Versioned<byte[]>(null, null));
            } else {
                promise.completeExceptionally(KeeperException.create(KeeperException.Code.get(rc)));
            }
        }
    }, null);
    return promise;
}