Java tutorial
/** * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance * with the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package com.alibaba.jstorm.schedule; import java.util.*; import com.alibaba.jstorm.blobstore.BlobStore; import com.alibaba.jstorm.blobstore.BlobStoreUtils; import com.alibaba.jstorm.blobstore.BlobSynchronizer; import com.alibaba.jstorm.blobstore.LocalFsBlobStore; import com.alibaba.jstorm.callback.Callback; import com.google.common.collect.Sets; import org.apache.commons.lang.StringUtils; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import com.alibaba.jstorm.callback.RunnableCallback; import com.alibaba.jstorm.client.ConfigExtension; import com.alibaba.jstorm.cluster.Cluster; import com.alibaba.jstorm.cluster.StormClusterState; import com.alibaba.jstorm.daemon.nimbus.NimbusData; import com.alibaba.jstorm.utils.JStormUtils; import com.alibaba.jstorm.utils.NetWorkUtils; import backtype.storm.Config; import backtype.storm.utils.Utils; public class FollowerRunnable implements Runnable { private static final Logger LOG = LoggerFactory.getLogger(FollowerRunnable.class); private NimbusData data; private int sleepTime; private volatile boolean state = true; private RunnableCallback blobSyncCallback; private Callback leaderCallback; private final String hostPort; public static final String NIMBUS_DIFFER_COUNT_ZK = "nimbus.differ.count.zk"; public static final Integer SLAVE_NIMBUS_WAIT_TIME = 60; @SuppressWarnings("unchecked") public FollowerRunnable(final NimbusData data, int sleepTime, Callback leaderCallback) { this.data = data; this.sleepTime = sleepTime; this.leaderCallback = leaderCallback; boolean isLocalIp; if (!ConfigExtension.isNimbusUseIp(data.getConf())) { this.hostPort = NetWorkUtils.hostname() + ":" + Utils.getInt(data.getConf().get(Config.NIMBUS_THRIFT_PORT)); isLocalIp = NetWorkUtils.hostname().equals("localhost"); } else { this.hostPort = NetWorkUtils.ip() + ":" + Utils.getInt(data.getConf().get(Config.NIMBUS_THRIFT_PORT)); isLocalIp = NetWorkUtils.ip().equals("127.0.0.1"); } try { if (isLocalIp) { throw new Exception("the hostname which nimbus get is localhost"); } } catch (Exception e1) { LOG.error("failed to get nimbus host!", e1); throw new RuntimeException(e1); } try { data.getStormClusterState().update_nimbus_slave(hostPort, data.uptime()); data.getStormClusterState().update_nimbus_detail(hostPort, null); } catch (Exception e) { LOG.error("failed to register nimbus host!", e); throw new RuntimeException(); } StormClusterState zkClusterState = data.getStormClusterState(); try { if (!zkClusterState.leader_existed()) { this.tryToBeLeader(data.getConf()); } } catch (Exception e) { LOG.error("failed to register nimbus details!", e); throw new RuntimeException(); } try { if (!zkClusterState.leader_existed()) { this.tryToBeLeader(data.getConf()); } } catch (Exception e1) { try { data.getStormClusterState().unregister_nimbus_host(hostPort); data.getStormClusterState().unregister_nimbus_detail(hostPort); } catch (Exception e2) { LOG.info("remove registered nimbus information due to task errors"); } finally { LOG.error("try to be leader error.", e1); throw new RuntimeException(e1); } } blobSyncCallback = new RunnableCallback() { @Override public void run() { blobSync(); } }; if (data.getBlobStore() instanceof LocalFsBlobStore) { try { // register call back for blob-store data.getStormClusterState().blobstore(blobSyncCallback); setupBlobstore(); } catch (Exception e) { LOG.error("setup blob store error", e); } } } // sets up blobstore state for all current keys private void setupBlobstore() throws Exception { BlobStore blobStore = data.getBlobStore(); StormClusterState clusterState = data.getStormClusterState(); Set<String> localSetOfKeys = Sets.newHashSet(blobStore.listKeys()); Set<String> allKeys = Sets.newHashSet(clusterState.active_keys()); Set<String> localAvailableActiveKeys = Sets.intersection(localSetOfKeys, allKeys); // keys on local but not on zk, we will delete it Set<String> keysToDelete = Sets.difference(localSetOfKeys, allKeys); LOG.debug("deleting keys not on zookeeper {}", keysToDelete); for (String key : keysToDelete) { blobStore.deleteBlob(key); } LOG.debug("Creating list of key entries for blobstore inside zookeeper {} local {}", allKeys, localAvailableActiveKeys); for (String key : localAvailableActiveKeys) { int versionForKey = BlobStoreUtils.getVersionForKey(key, data.getNimbusHostPortInfo(), data.getConf()); clusterState.setup_blobstore(key, data.getNimbusHostPortInfo(), versionForKey); } } public boolean isLeader(String zkMaster) { if (StringUtils.isBlank(zkMaster)) { return false; } if (hostPort.equalsIgnoreCase(zkMaster)) { return true; } // Two nimbus running on the same node isn't allowed // so just checks ip is enough here String[] part = zkMaster.split(":"); return NetWorkUtils.equals(part[0], NetWorkUtils.ip()); } @Override public void run() { LOG.info("Follower thread starts!"); while (state) { StormClusterState zkClusterState = data.getStormClusterState(); try { Thread.sleep(sleepTime); if (!zkClusterState.leader_existed()) { this.tryToBeLeader(data.getConf()); continue; } String master = zkClusterState.get_leader_host(); boolean isZkLeader = isLeader(master); if (isZkLeader) { if (!data.isLeader()) { zkClusterState.unregister_nimbus_host(hostPort); zkClusterState.unregister_nimbus_detail(hostPort); data.setLeader(true); leaderCallback.execute(); } continue; } else { if (data.isLeader()) { LOG.info("New zk master is " + master); JStormUtils.halt_process(1, "Lost zk master node, halt process"); return; } } // here the nimbus is not leader if (data.getBlobStore() instanceof LocalFsBlobStore) { blobSync(); } zkClusterState.update_nimbus_slave(hostPort, data.uptime()); update_nimbus_detail(); } catch (InterruptedException ignored) { } catch (Exception e) { if (state) { LOG.error("Unknown exception ", e); } } } LOG.info("Follower thread has been closed!"); } public void clean() { state = false; } private synchronized void blobSync() { if (!data.isLeader()) { try { BlobStore blobStore = data.getBlobStore(); StormClusterState clusterState = data.getStormClusterState(); Set<String> localKeys = Sets.newHashSet(blobStore.listKeys()); Set<String> zkKeys = Sets.newHashSet(clusterState.blobstore(blobSyncCallback)); BlobSynchronizer blobSynchronizer = new BlobSynchronizer(blobStore, data.getConf()); blobSynchronizer.setNimbusInfo(data.getNimbusHostPortInfo()); blobSynchronizer.setBlobStoreKeySet(localKeys); blobSynchronizer.setZookeeperKeySet(zkKeys); blobSynchronizer.syncBlobs(); } catch (Exception e) { LOG.error("blob sync error", e); } } } private void tryToBeLeader(final Map conf) throws Exception { boolean allowed = check_nimbus_priority(); if (allowed) { RunnableCallback masterCallback = new RunnableCallback() { @Override public void run() { try { tryToBeLeader(conf); } catch (Exception e) { LOG.error("tryToBeLeader error", e); // 30??? JStormUtils.halt_process(30, "Cant't be master" + e.getMessage()); } } }; LOG.info("This nimbus can be leader"); data.getStormClusterState().try_to_be_leader(Cluster.MASTER_SUBTREE, hostPort, masterCallback); } else { LOG.info("This nimbus can't be leader"); } } /** * Compared with other nimbus to get priority of this nimbus */ private boolean check_nimbus_priority() throws Exception { int gap = update_nimbus_detail(); if (gap == 0) { return true; } int left = SLAVE_NIMBUS_WAIT_TIME; while (left > 0) { LOG.info("nimbus.differ.count.zk is {}, so after {} seconds, nimbus will try to be leader!", gap, left); Thread.sleep(10 * 1000); left -= 10; } StormClusterState zkClusterState = data.getStormClusterState(); List<String> followers = zkClusterState.list_dirs(Cluster.NIMBUS_SLAVE_DETAIL_SUBTREE, false); if (followers == null || followers.size() == 0) { return false; } for (String follower : followers) { if (follower != null && !follower.equals(hostPort)) { Map bMap = zkClusterState.get_nimbus_detail(follower, false); if (bMap != null) { Object object = bMap.get(NIMBUS_DIFFER_COUNT_ZK); if (object != null && (JStormUtils.parseInt(object)) < gap) { LOG.info("Current node can't be leader, due to {} has higher priority", follower); return false; } } } } return true; } private int update_nimbus_detail() throws Exception { //update count = count of zk's binary files - count of nimbus's binary files StormClusterState zkClusterState = data.getStormClusterState(); // if we use other blobstore, such as HDFS, all nimbus slave can be leader // but if we use local blobstore, we should count topologies files int diffCount = 0; if (data.getBlobStore() instanceof LocalFsBlobStore) { Set<String> keysOnZk = Sets.newHashSet(zkClusterState.active_keys()); Set<String> keysOnLocal = Sets.newHashSet(data.getBlobStore().listKeys()); // we count number of keys which is on zk but not on local diffCount = Sets.difference(keysOnZk, keysOnLocal).size(); } Map mtmp = zkClusterState.get_nimbus_detail(hostPort, false); if (mtmp == null) { mtmp = new HashMap(); } mtmp.put(NIMBUS_DIFFER_COUNT_ZK, diffCount); zkClusterState.update_nimbus_detail(hostPort, mtmp); LOG.debug("update nimbus details " + mtmp); return diffCount; } /** * Check whether current node is master */ private void checkOwnMaster() throws Exception { int retry_times = 10; StormClusterState zkClient = data.getStormClusterState(); for (int i = 0; i < retry_times; i++, JStormUtils.sleepMs(sleepTime)) { if (!zkClient.leader_existed()) { continue; } String zkHost = zkClient.get_leader_host(); if (hostPort.equals(zkHost)) { // current process own master return; } LOG.warn("Current nimbus has started thrift, but fail to set as leader in zk:" + zkHost); } String err = "Current nimbus failed to set as leader in zk, halting process"; LOG.error(err); JStormUtils.halt_process(0, err); } }