Examples with LeaderLatchListener org.apache.curator.framework.recipes.leader.LeaderLatchListener used on opensource projects

Example 1 with LeaderLatchListener

use of org.apache.curator.framework.recipes.leader.LeaderLatchListener in project storm by apache.

the class Zookeeper method zkLeaderElectorImpl.

protected ILeaderElector zkLeaderElectorImpl(Map conf, BlobStore blobStore) throws UnknownHostException {
    List<String> servers = (List<String>) conf.get(Config.STORM_ZOOKEEPER_SERVERS);
    Object port = conf.get(Config.STORM_ZOOKEEPER_PORT);
    CuratorFramework zk = mkClientImpl(conf, servers, port, "", conf);
    String leaderLockPath = conf.get(Config.STORM_ZOOKEEPER_ROOT) + "/leader-lock";
    String id = NimbusInfo.fromConf(conf).toHostPortString();
    AtomicReference<LeaderLatch> leaderLatchAtomicReference = new AtomicReference<>(new LeaderLatch(zk, leaderLockPath, id));
    AtomicReference<LeaderLatchListener> leaderLatchListenerAtomicReference = new AtomicReference<>(leaderLatchListenerImpl(conf, zk, blobStore, leaderLatchAtomicReference.get()));
    return new LeaderElectorImp(conf, servers, zk, leaderLockPath, id, leaderLatchAtomicReference, leaderLatchListenerAtomicReference, blobStore);
}

Example 2 with LeaderLatchListener

use of org.apache.curator.framework.recipes.leader.LeaderLatchListener in project storm by apache.

the class Zookeeper method leaderLatchListenerImpl.

// Leader latch listener that will be invoked when we either gain or lose leadership
public static LeaderLatchListener leaderLatchListenerImpl(final Map conf, final CuratorFramework zk, final BlobStore blobStore, final LeaderLatch leaderLatch) throws UnknownHostException {
    final String hostName = InetAddress.getLocalHost().getCanonicalHostName();
    return new LeaderLatchListener() {

        final String STORM_JAR_SUFFIX = "-stormjar.jar";

        final String STORM_CODE_SUFFIX = "-stormcode.ser";

        final String STORM_CONF_SUFFIX = "-stormconf.ser";

        @Override
        public void isLeader() {
            Set<String> activeTopologyIds = new TreeSet<>(Zookeeper.getChildren(zk, conf.get(Config.STORM_ZOOKEEPER_ROOT) + ClusterUtils.STORMS_SUBTREE, false));
            Set<String> activeTopologyBlobKeys = populateTopologyBlobKeys(activeTopologyIds);
            Set<String> activeTopologyCodeKeys = filterTopologyCodeKeys(activeTopologyBlobKeys);
            Set<String> allLocalBlobKeys = Sets.newHashSet(blobStore.listKeys());
            Set<String> allLocalTopologyBlobKeys = filterTopologyBlobKeys(allLocalBlobKeys);
            // this finds all active topologies blob keys from all local topology blob keys
            Sets.SetView<String> diffTopology = Sets.difference(activeTopologyBlobKeys, allLocalTopologyBlobKeys);
            LOG.info("active-topology-blobs [{}] local-topology-blobs [{}] diff-topology-blobs [{}]", generateJoinedString(activeTopologyIds), generateJoinedString(allLocalTopologyBlobKeys), generateJoinedString(diffTopology));
            if (diffTopology.isEmpty()) {
                Set<String> activeTopologyDependencies = getTopologyDependencyKeys(activeTopologyCodeKeys);
                // this finds all dependency blob keys from active topologies from all local blob keys
                Sets.SetView<String> diffDependencies = Sets.difference(activeTopologyDependencies, allLocalBlobKeys);
                LOG.info("active-topology-dependencies [{}] local-blobs [{}] diff-topology-dependencies [{}]", generateJoinedString(activeTopologyDependencies), generateJoinedString(allLocalBlobKeys), generateJoinedString(diffDependencies));
                if (diffDependencies.isEmpty()) {
                    LOG.info("Accepting leadership, all active topologies and corresponding dependencies found locally.");
                } else {
                    LOG.info("Code for all active topologies is available locally, but some dependencies are not found locally, giving up leadership.");
                    closeLatch();
                }
            } else {
                LOG.info("code for all active topologies not available locally, giving up leadership.");
                closeLatch();
            }
        }

        @Override
        public void notLeader() {
            LOG.info("{} lost leadership.", hostName);
        }

        private String generateJoinedString(Set<String> activeTopologyIds) {
            return Joiner.on(",").join(activeTopologyIds);
        }

        private Set<String> populateTopologyBlobKeys(Set<String> activeTopologyIds) {
            Set<String> activeTopologyBlobKeys = new TreeSet<>();
            for (String activeTopologyId : activeTopologyIds) {
                activeTopologyBlobKeys.add(activeTopologyId + STORM_JAR_SUFFIX);
                activeTopologyBlobKeys.add(activeTopologyId + STORM_CODE_SUFFIX);
                activeTopologyBlobKeys.add(activeTopologyId + STORM_CONF_SUFFIX);
            }
            return activeTopologyBlobKeys;
        }

        private Set<String> filterTopologyBlobKeys(Set<String> blobKeys) {
            Set<String> topologyBlobKeys = new HashSet<>();
            for (String blobKey : blobKeys) {
                if (blobKey.endsWith(STORM_JAR_SUFFIX) || blobKey.endsWith(STORM_CODE_SUFFIX) || blobKey.endsWith(STORM_CONF_SUFFIX)) {
                    topologyBlobKeys.add(blobKey);
                }
            }
            return topologyBlobKeys;
        }

        private Set<String> filterTopologyCodeKeys(Set<String> blobKeys) {
            Set<String> topologyCodeKeys = new HashSet<>();
            for (String blobKey : blobKeys) {
                if (blobKey.endsWith(STORM_CODE_SUFFIX)) {
                    topologyCodeKeys.add(blobKey);
                }
            }
            return topologyCodeKeys;
        }

        private Set<String> getTopologyDependencyKeys(Set<String> activeTopologyCodeKeys) {
            Set<String> activeTopologyDependencies = new TreeSet<>();
            Subject subject = ReqContext.context().subject();
            for (String activeTopologyCodeKey : activeTopologyCodeKeys) {
                try {
                    InputStreamWithMeta blob = blobStore.getBlob(activeTopologyCodeKey, subject);
                    byte[] blobContent = IOUtils.readFully(blob, new Long(blob.getFileLength()).intValue());
                    StormTopology stormCode = Utils.deserialize(blobContent, StormTopology.class);
                    if (stormCode.is_set_dependency_jars()) {
                        activeTopologyDependencies.addAll(stormCode.get_dependency_jars());
                    }
                    if (stormCode.is_set_dependency_artifacts()) {
                        activeTopologyDependencies.addAll(stormCode.get_dependency_artifacts());
                    }
                } catch (AuthorizationException | KeyNotFoundException | IOException e) {
                    LOG.error("Exception occurs while reading blob for key: " + activeTopologyCodeKey + ", exception: " + e, e);
                    throw new RuntimeException("Exception occurs while reading blob for key: " + activeTopologyCodeKey + ", exception: " + e, e);
                }
            }
            return activeTopologyDependencies;
        }

        private void closeLatch() {
            try {
                leaderLatch.close();
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
        }
    };
}

Example 3 with LeaderLatchListener

use of org.apache.curator.framework.recipes.leader.LeaderLatchListener in project druid by druid-io.

the class DruidCoordinator method createNewLeaderLatch.

private LeaderLatch createNewLeaderLatch() {
    final LeaderLatch newLeaderLatch = new LeaderLatch(curator, ZKPaths.makePath(zkPaths.getCoordinatorPath(), COORDINATOR_OWNER_NODE), self.getHostAndPort());
    newLeaderLatch.addListener(new LeaderLatchListener() {

        @Override
        public void isLeader() {
            DruidCoordinator.this.becomeLeader();
        }

        @Override
        public void notLeader() {
            DruidCoordinator.this.stopBeingLeader();
        }
    }, Execs.singleThreaded("CoordinatorLeader-%s"));
    return leaderLatch.getAndSet(newLeaderLatch);
}