Examples with PathChildrenCache org.apache.curator.framework.recipes.cache.PathChildrenCache used on opensource projects

Example 21 with PathChildrenCache

use of org.apache.curator.framework.recipes.cache.PathChildrenCache in project flink by apache.

the class ZooKeeperUtils method createJobGraphs.

/**
 * Creates a {@link DefaultJobGraphStore} instance with {@link ZooKeeperStateHandleStore},
 * {@link ZooKeeperJobGraphStoreWatcher} and {@link ZooKeeperJobGraphStoreUtil}.
 *
 * @param client The {@link CuratorFramework} ZooKeeper client to use
 * @param configuration {@link Configuration} object
 * @return {@link DefaultJobGraphStore} instance
 * @throws Exception if the submitted job graph store cannot be created
 */
public static JobGraphStore createJobGraphs(CuratorFramework client, Configuration configuration) throws Exception {
    checkNotNull(configuration, "Configuration");
    RetrievableStateStorageHelper<JobGraph> stateStorage = createFileSystemStateStorage(configuration, HA_STORAGE_SUBMITTED_JOBGRAPH_PREFIX);
    // ZooKeeper submitted jobs root dir
    String zooKeeperJobsPath = configuration.getString(HighAvailabilityOptions.HA_ZOOKEEPER_JOBGRAPHS_PATH);
    // Ensure that the job graphs path exists
    client.newNamespaceAwareEnsurePath(zooKeeperJobsPath).ensure(client.getZookeeperClient());
    // All operations will have the path as root
    CuratorFramework facade = client.usingNamespace(client.getNamespace() + zooKeeperJobsPath);
    final String zooKeeperFullJobsPath = client.getNamespace() + zooKeeperJobsPath;
    final ZooKeeperStateHandleStore<JobGraph> zooKeeperStateHandleStore = new ZooKeeperStateHandleStore<>(facade, stateStorage);
    final PathChildrenCache pathCache = new PathChildrenCache(facade, "/", false);
    return new DefaultJobGraphStore<>(zooKeeperStateHandleStore, new ZooKeeperJobGraphStoreWatcher(pathCache), ZooKeeperJobGraphStoreUtil.INSTANCE);
}

Example 22 with PathChildrenCache

use of org.apache.curator.framework.recipes.cache.PathChildrenCache in project flink by apache.

the class ZooKeeperJobGraphStoreWatcherTest method createAndStartJobGraphStoreWatcher.

private JobGraphStoreWatcher createAndStartJobGraphStoreWatcher(CuratorFramework client) throws Exception {
    final ZooKeeperJobGraphStoreWatcher jobGraphStoreWatcher = new ZooKeeperJobGraphStoreWatcher(new PathChildrenCache(client, "/", false));
    jobGraphStoreWatcher.start(testingJobGraphListener);
    return jobGraphStoreWatcher;
}

Example 23 with PathChildrenCache

use of org.apache.curator.framework.recipes.cache.PathChildrenCache in project druid by druid-io.

the class Announcer method announce.

/**
 * Announces the provided bytes at the given path.  Announcement means that it will create an ephemeral node
 * and monitor it to make sure that it always exists until it is unannounced or this object is closed.
 *
 * @param path                  The path to announce at
 * @param bytes                 The payload to announce
 * @param removeParentIfCreated remove parent of "path" if we had created that parent
 */
public void announce(String path, byte[] bytes, boolean removeParentIfCreated) {
    synchronized (toAnnounce) {
        if (!started) {
            toAnnounce.add(new Announceable(path, bytes, removeParentIfCreated));
            return;
        }
    }
    final ZKPaths.PathAndNode pathAndNode = ZKPaths.getPathAndNode(path);
    final String parentPath = pathAndNode.getPath();
    boolean buildParentPath = false;
    ConcurrentMap<String, byte[]> subPaths = announcements.get(parentPath);
    if (subPaths == null) {
        try {
            if (curator.checkExists().forPath(parentPath) == null) {
                buildParentPath = true;
            }
        } catch (Exception e) {
            log.debug(e, "Problem checking if the parent existed, ignoring.");
        }
        // I don't have a watcher on this path yet, create a Map and start watching.
        announcements.putIfAbsent(parentPath, new ConcurrentHashMap<>());
        // Guaranteed to be non-null, but might be a map put in there by another thread.
        final ConcurrentMap<String, byte[]> finalSubPaths = announcements.get(parentPath);
        // Synchronize to make sure that I only create a listener once.
        synchronized (finalSubPaths) {
            if (!listeners.containsKey(parentPath)) {
                final PathChildrenCache cache = factory.make(curator, parentPath);
                cache.getListenable().addListener(new PathChildrenCacheListener() {

                    private final AtomicReference<Set<String>> pathsLost = new AtomicReference<Set<String>>(null);

                    @Override
                    public void childEvent(CuratorFramework client, PathChildrenCacheEvent event) throws Exception {
                        // NOTE: ZooKeeper does not guarantee that we will get every event, and thus PathChildrenCache doesn't
                        // as well. If one of the below events are missed, Announcer might not work properly.
                        log.debug("Path[%s] got event[%s]", parentPath, event);
                        switch(event.getType()) {
                            case CHILD_REMOVED:
                                final ChildData child = event.getData();
                                final ZKPaths.PathAndNode childPath = ZKPaths.getPathAndNode(child.getPath());
                                final byte[] value = finalSubPaths.get(childPath.getNode());
                                if (value != null) {
                                    log.info("Node[%s] dropped, reinstating.", child.getPath());
                                    createAnnouncement(child.getPath(), value);
                                }
                                break;
                            case CONNECTION_LOST:
                                // Lost connection, which means session is broken, take inventory of what has been seen.
                                // This is to protect from a race condition in which the ephemeral node could have been
                                // created but not actually seen by the PathChildrenCache, which means that it won't know
                                // that it disappeared and thus will not generate a CHILD_REMOVED event for us.  Under normal
                                // circumstances, this can only happen upon connection loss; but technically if you have
                                // an adversary in the system, they could also delete the ephemeral node before the cache sees
                                // it.  This does not protect from that case, so don't have adversaries.
                                Set<String> pathsToReinstate = new HashSet<>();
                                for (String node : finalSubPaths.keySet()) {
                                    String path = ZKPaths.makePath(parentPath, node);
                                    log.info("Node[%s] is added to reinstate.", path);
                                    pathsToReinstate.add(path);
                                }
                                if (!pathsToReinstate.isEmpty() && !pathsLost.compareAndSet(null, pathsToReinstate)) {
                                    log.info("Already had a pathsLost set!?[%s]", parentPath);
                                }
                                break;
                            case CONNECTION_RECONNECTED:
                                final Set<String> thePathsLost = pathsLost.getAndSet(null);
                                if (thePathsLost != null) {
                                    for (String path : thePathsLost) {
                                        log.info("Reinstating [%s]", path);
                                        final ZKPaths.PathAndNode split = ZKPaths.getPathAndNode(path);
                                        createAnnouncement(path, announcements.get(split.getPath()).get(split.getNode()));
                                    }
                                }
                                break;
                            case CHILD_ADDED:
                                if (addedChildren != null) {
                                    addedChildren.add(event.getData().getPath());
                                }
                            // fall through
                            case INITIALIZED:
                            case CHILD_UPDATED:
                            case CONNECTION_SUSPENDED:
                        }
                    }
                });
                synchronized (toAnnounce) {
                    if (started) {
                        if (buildParentPath) {
                            createPath(parentPath, removeParentIfCreated);
                        }
                        startCache(cache);
                        listeners.put(parentPath, cache);
                    }
                }
            }
        }
        subPaths = finalSubPaths;
    }
    boolean created = false;
    synchronized (toAnnounce) {
        if (started) {
            byte[] oldBytes = subPaths.putIfAbsent(pathAndNode.getNode(), bytes);
            if (oldBytes == null) {
                created = true;
            } else if (!Arrays.equals(oldBytes, bytes)) {
                throw new IAE("Cannot reannounce different values under the same path");
            }
        }
    }
    if (created) {
        try {
            createAnnouncement(path, bytes);
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }
}

Example 24 with PathChildrenCache

use of org.apache.curator.framework.recipes.cache.PathChildrenCache in project druid by druid-io.

the class DruidCoordinatorTest method testComputeUnderReplicationCountsPerDataSourcePerTierForSegmentsWithBroadcastRule.

@Test(timeout = 60_000L)
public void testComputeUnderReplicationCountsPerDataSourcePerTierForSegmentsWithBroadcastRule() throws Exception {
    final String dataSource = "dataSource";
    final String hotTierName = "hot";
    final String coldTierName = "cold";
    final String tierName1 = "tier1";
    final String tierName2 = "tier2";
    final Rule broadcastDistributionRule = new ForeverBroadcastDistributionRule();
    final String loadPathCold = "/druid/loadqueue/cold:1234";
    final String loadPathBroker1 = "/druid/loadqueue/broker1:1234";
    final String loadPathBroker2 = "/druid/loadqueue/broker2:1234";
    final String loadPathPeon = "/druid/loadqueue/peon:1234";
    final DruidServer hotServer = new DruidServer("hot", "hot", null, 5L, ServerType.HISTORICAL, hotTierName, 0);
    final DruidServer coldServer = new DruidServer("cold", "cold", null, 5L, ServerType.HISTORICAL, coldTierName, 0);
    final DruidServer brokerServer1 = new DruidServer("broker1", "broker1", null, 5L, ServerType.BROKER, tierName1, 0);
    final DruidServer brokerServer2 = new DruidServer("broker2", "broker2", null, 5L, ServerType.BROKER, tierName2, 0);
    final DruidServer peonServer = new DruidServer("peon", "peon", null, 5L, ServerType.INDEXER_EXECUTOR, tierName2, 0);
    final Map<String, DataSegment> dataSegments = ImmutableMap.of("2018-01-02T00:00:00.000Z_2018-01-03T00:00:00.000Z", new DataSegment(dataSource, Intervals.of("2018-01-02/P1D"), "v1", null, null, null, null, 0x9, 0), "2018-01-03T00:00:00.000Z_2018-01-04T00:00:00.000Z", new DataSegment(dataSource, Intervals.of("2018-01-03/P1D"), "v1", null, null, null, null, 0x9, 0), "2017-01-01T00:00:00.000Z_2017-01-02T00:00:00.000Z", new DataSegment(dataSource, Intervals.of("2017-01-01/P1D"), "v1", null, null, null, null, 0x9, 0));
    final LoadQueuePeon loadQueuePeonCold = new CuratorLoadQueuePeon(curator, loadPathCold, objectMapper, Execs.scheduledSingleThreaded("coordinator_test_load_queue_peon_cold_scheduled-%d"), Execs.singleThreaded("coordinator_test_load_queue_peon_cold-%d"), druidCoordinatorConfig);
    final LoadQueuePeon loadQueuePeonBroker1 = new CuratorLoadQueuePeon(curator, loadPathBroker1, objectMapper, Execs.scheduledSingleThreaded("coordinator_test_load_queue_peon_broker1_scheduled-%d"), Execs.singleThreaded("coordinator_test_load_queue_peon_broker1-%d"), druidCoordinatorConfig);
    final LoadQueuePeon loadQueuePeonBroker2 = new CuratorLoadQueuePeon(curator, loadPathBroker2, objectMapper, Execs.scheduledSingleThreaded("coordinator_test_load_queue_peon_broker2_scheduled-%d"), Execs.singleThreaded("coordinator_test_load_queue_peon_broker2-%d"), druidCoordinatorConfig);
    final LoadQueuePeon loadQueuePeonPoenServer = new CuratorLoadQueuePeon(curator, loadPathPeon, objectMapper, Execs.scheduledSingleThreaded("coordinator_test_load_queue_peon_peon_scheduled-%d"), Execs.singleThreaded("coordinator_test_load_queue_peon_peon-%d"), druidCoordinatorConfig);
    final PathChildrenCache pathChildrenCacheCold = new PathChildrenCache(curator, loadPathCold, true, true, Execs.singleThreaded("coordinator_test_path_children_cache_cold-%d"));
    final PathChildrenCache pathChildrenCacheBroker1 = new PathChildrenCache(curator, loadPathBroker1, true, true, Execs.singleThreaded("coordinator_test_path_children_cache_broker1-%d"));
    final PathChildrenCache pathChildrenCacheBroker2 = new PathChildrenCache(curator, loadPathBroker2, true, true, Execs.singleThreaded("coordinator_test_path_children_cache_broker2-%d"));
    final PathChildrenCache pathChildrenCachePeon = new PathChildrenCache(curator, loadPathPeon, true, true, Execs.singleThreaded("coordinator_test_path_children_cache_peon-%d"));
    loadManagementPeons.putAll(ImmutableMap.of("hot", loadQueuePeon, "cold", loadQueuePeonCold, "broker1", loadQueuePeonBroker1, "broker2", loadQueuePeonBroker2, "peon", loadQueuePeonPoenServer));
    loadQueuePeonCold.start();
    loadQueuePeonBroker1.start();
    loadQueuePeonBroker2.start();
    loadQueuePeonPoenServer.start();
    pathChildrenCache.start();
    pathChildrenCacheCold.start();
    pathChildrenCacheBroker1.start();
    pathChildrenCacheBroker2.start();
    pathChildrenCachePeon.start();
    DruidDataSource[] druidDataSources = { new DruidDataSource(dataSource, Collections.emptyMap()) };
    dataSegments.values().forEach(druidDataSources[0]::addSegment);
    setupSegmentsMetadataMock(druidDataSources[0]);
    EasyMock.expect(metadataRuleManager.getRulesWithDefault(EasyMock.anyString())).andReturn(ImmutableList.of(broadcastDistributionRule)).atLeastOnce();
    EasyMock.expect(metadataRuleManager.getAllRules()).andReturn(ImmutableMap.of(dataSource, ImmutableList.of(broadcastDistributionRule))).atLeastOnce();
    EasyMock.expect(serverInventoryView.getInventory()).andReturn(ImmutableList.of(hotServer, coldServer, brokerServer1, brokerServer2, peonServer)).atLeastOnce();
    EasyMock.expect(serverInventoryView.isStarted()).andReturn(true).anyTimes();
    EasyMock.replay(metadataRuleManager, serverInventoryView);
    coordinator.start();
    // Wait for this coordinator to become leader
    leaderAnnouncerLatch.await();
    final CountDownLatch assignSegmentLatchHot = createCountDownLatchAndSetPathChildrenCacheListenerWithLatch(3, pathChildrenCache, dataSegments, hotServer);
    final CountDownLatch assignSegmentLatchCold = createCountDownLatchAndSetPathChildrenCacheListenerWithLatch(3, pathChildrenCacheCold, dataSegments, coldServer);
    final CountDownLatch assignSegmentLatchBroker1 = createCountDownLatchAndSetPathChildrenCacheListenerWithLatch(3, pathChildrenCacheBroker1, dataSegments, brokerServer1);
    final CountDownLatch assignSegmentLatchBroker2 = createCountDownLatchAndSetPathChildrenCacheListenerWithLatch(3, pathChildrenCacheBroker2, dataSegments, brokerServer2);
    final CountDownLatch assignSegmentLatchPeon = createCountDownLatchAndSetPathChildrenCacheListenerWithLatch(3, pathChildrenCachePeon, dataSegments, peonServer);
    assignSegmentLatchHot.await();
    assignSegmentLatchCold.await();
    assignSegmentLatchBroker1.await();
    assignSegmentLatchBroker2.await();
    assignSegmentLatchPeon.await();
    final CountDownLatch coordinatorRunLatch = new CountDownLatch(2);
    serviceEmitter.latch = coordinatorRunLatch;
    coordinatorRunLatch.await();
    Assert.assertEquals(ImmutableMap.of(dataSource, 100.0), coordinator.getLoadStatus());
    Map<String, Object2LongMap<String>> underReplicationCountsPerDataSourcePerTier = coordinator.computeUnderReplicationCountsPerDataSourcePerTier();
    Assert.assertEquals(4, underReplicationCountsPerDataSourcePerTier.size());
    Assert.assertEquals(0L, underReplicationCountsPerDataSourcePerTier.get(hotTierName).getLong(dataSource));
    Assert.assertEquals(0L, underReplicationCountsPerDataSourcePerTier.get(coldTierName).getLong(dataSource));
    Assert.assertEquals(0L, underReplicationCountsPerDataSourcePerTier.get(tierName1).getLong(dataSource));
    Assert.assertEquals(0L, underReplicationCountsPerDataSourcePerTier.get(tierName2).getLong(dataSource));
    Map<String, Object2LongMap<String>> underReplicationCountsPerDataSourcePerTierUsingClusterView = coordinator.computeUnderReplicationCountsPerDataSourcePerTierUsingClusterView();
    Assert.assertEquals(4, underReplicationCountsPerDataSourcePerTierUsingClusterView.size());
    Assert.assertEquals(0L, underReplicationCountsPerDataSourcePerTierUsingClusterView.get(hotTierName).getLong(dataSource));
    Assert.assertEquals(0L, underReplicationCountsPerDataSourcePerTierUsingClusterView.get(coldTierName).getLong(dataSource));
    Assert.assertEquals(0L, underReplicationCountsPerDataSourcePerTierUsingClusterView.get(tierName1).getLong(dataSource));
    Assert.assertEquals(0L, underReplicationCountsPerDataSourcePerTierUsingClusterView.get(tierName2).getLong(dataSource));
    coordinator.stop();
    leaderUnannouncerLatch.await();
    EasyMock.verify(serverInventoryView);
    EasyMock.verify(segmentsMetadataManager);
    EasyMock.verify(metadataRuleManager);
}

Example 25 with PathChildrenCache

use of org.apache.curator.framework.recipes.cache.PathChildrenCache in project druid by druid-io.

the class ZkCoordinator method start.

@LifecycleStart
public void start() throws IOException {
    synchronized (lock) {
        if (started) {
            return;
        }
        log.info("Starting zkCoordinator for server[%s]", me.getName());
        final String loadQueueLocation = ZKPaths.makePath(zkPaths.getLoadQueuePath(), me.getName());
        final String servedSegmentsLocation = ZKPaths.makePath(zkPaths.getServedSegmentsPath(), me.getName());
        final String liveSegmentsLocation = ZKPaths.makePath(zkPaths.getLiveSegmentsPath(), me.getName());
        loadQueueCache = new PathChildrenCache(curator, loadQueueLocation, true, true, Execs.singleThreaded("ZkCoordinator"));
        try {
            curator.newNamespaceAwareEnsurePath(loadQueueLocation).ensure(curator.getZookeeperClient());
            curator.newNamespaceAwareEnsurePath(servedSegmentsLocation).ensure(curator.getZookeeperClient());
            curator.newNamespaceAwareEnsurePath(liveSegmentsLocation).ensure(curator.getZookeeperClient());
            loadQueueCache.getListenable().addListener((client, event) -> {
                final ChildData child = event.getData();
                switch(event.getType()) {
                    case CHILD_ADDED:
                        childAdded(child);
                        break;
                    case CHILD_REMOVED:
                        log.info("zNode[%s] was removed", event.getData().getPath());
                        break;
                    default:
                        log.info("Ignoring event[%s]", event);
                }
            });
            loadQueueCache.start();
        } catch (Exception e) {
            Throwables.propagateIfPossible(e, IOException.class);
            throw new RuntimeException(e);
        }
        started = true;
    }
}