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 org.apache.zookeeper.server.quorum; import java.io.IOException; import javax.management.JMException; import javax.security.sasl.SaslException; import org.apache.yetus.audience.InterfaceAudience; import org.apache.zookeeper.audit.ZKAuditProvider; import org.apache.zookeeper.jmx.ManagedUtil; import org.apache.zookeeper.metrics.MetricsProvider; import org.apache.zookeeper.metrics.MetricsProviderLifeCycleException; import org.apache.zookeeper.metrics.impl.MetricsProviderBootstrap; import org.apache.zookeeper.server.DatadirCleanupManager; import org.apache.zookeeper.server.ExitCode; import org.apache.zookeeper.server.ServerCnxnFactory; import org.apache.zookeeper.server.ServerMetrics; import org.apache.zookeeper.server.ZKDatabase; import org.apache.zookeeper.server.ZooKeeperServerMain; import org.apache.zookeeper.server.admin.AdminServer.AdminServerException; import org.apache.zookeeper.server.persistence.FileTxnSnapLog; import org.apache.zookeeper.server.persistence.FileTxnSnapLog.DatadirException; import org.apache.zookeeper.server.quorum.QuorumPeerConfig.ConfigException; import org.apache.zookeeper.server.util.JvmPauseMonitor; import org.apache.zookeeper.util.ServiceUtils; import org.slf4j.Logger; import org.slf4j.LoggerFactory; /** * * <h2>Configuration file</h2> * * When the main() method of this class is used to start the program, the first * argument is used as a path to the config file, which will be used to obtain * configuration information. This file is a Properties file, so keys and * values are separated by equals (=) and the key/value pairs are separated * by new lines. The following is a general summary of keys used in the * configuration file. For full details on this see the documentation in * docs/index.html * <ol> * <li>dataDir - The directory where the ZooKeeper data is stored.</li> * <li>dataLogDir - The directory where the ZooKeeper transaction log is stored.</li> * <li>clientPort - The port used to communicate with clients.</li> * <li>tickTime - The duration of a tick in milliseconds. This is the basic * unit of time in ZooKeeper.</li> * <li>initLimit - The maximum number of ticks that a follower will wait to * initially synchronize with a leader.</li> * <li>syncLimit - The maximum number of ticks that a follower will wait for a * message (including heartbeats) from the leader.</li> * <li>server.<i>id</i> - This is the host:port[:port] that the server with the * given id will use for the quorum protocol.</li> * </ol> * In addition to the config file. There is a file in the data directory called * "myid" that contains the server id as an ASCII decimal value. * */ @InterfaceAudience.Public public class QuorumPeerMain { private static final Logger LOG = LoggerFactory.getLogger(QuorumPeerMain.class); private static final String USAGE = "Usage: QuorumPeerMain configfile"; protected QuorumPeer quorumPeer; /** * To start the replicated server specify the configuration file name on * the command line. * @param args path to the configfile */ public static void main(String[] args) { QuorumPeerMain main = new QuorumPeerMain(); try { main.initializeAndRun(args); } catch (IllegalArgumentException e) { LOG.error("Invalid arguments, exiting abnormally", e); LOG.info(USAGE); System.err.println(USAGE); ZKAuditProvider.addServerStartFailureAuditLog(); ServiceUtils.requestSystemExit(ExitCode.INVALID_INVOCATION.getValue()); } catch (ConfigException e) { LOG.error("Invalid config, exiting abnormally", e); System.err.println("Invalid config, exiting abnormally"); ZKAuditProvider.addServerStartFailureAuditLog(); ServiceUtils.requestSystemExit(ExitCode.INVALID_INVOCATION.getValue()); } catch (DatadirException e) { LOG.error("Unable to access datadir, exiting abnormally", e); System.err.println("Unable to access datadir, exiting abnormally"); ZKAuditProvider.addServerStartFailureAuditLog(); ServiceUtils.requestSystemExit(ExitCode.UNABLE_TO_ACCESS_DATADIR.getValue()); } catch (AdminServerException e) { LOG.error("Unable to start AdminServer, exiting abnormally", e); System.err.println("Unable to start AdminServer, exiting abnormally"); ZKAuditProvider.addServerStartFailureAuditLog(); ServiceUtils.requestSystemExit(ExitCode.ERROR_STARTING_ADMIN_SERVER.getValue()); } catch (Exception e) { LOG.error("Unexpected exception, exiting abnormally", e); ZKAuditProvider.addServerStartFailureAuditLog(); ServiceUtils.requestSystemExit(ExitCode.UNEXPECTED_ERROR.getValue()); } LOG.info("Exiting normally"); ServiceUtils.requestSystemExit(ExitCode.EXECUTION_FINISHED.getValue()); } protected void initializeAndRun(String[] args) throws ConfigException, IOException, AdminServerException { QuorumPeerConfig config = new QuorumPeerConfig(); if (args.length == 1) { config.parse(args[0]); } // Start and schedule the the purge task DatadirCleanupManager purgeMgr = new DatadirCleanupManager(config.getDataDir(), config.getDataLogDir(), config.getSnapRetainCount(), config.getPurgeInterval()); purgeMgr.start(); if (args.length == 1 && config.isDistributed()) { runFromConfig(config); } else { LOG.warn("Either no config or no quorum defined in config, running in standalone mode"); // there is only server in the quorum -- run as standalone ZooKeeperServerMain.main(args); } } public void runFromConfig(QuorumPeerConfig config) throws IOException, AdminServerException { try { ManagedUtil.registerLog4jMBeans(); } catch (JMException e) { LOG.warn("Unable to register log4j JMX control", e); } LOG.info("Starting quorum peer"); MetricsProvider metricsProvider; try { metricsProvider = MetricsProviderBootstrap.startMetricsProvider(config.getMetricsProviderClassName(), config.getMetricsProviderConfiguration()); } catch (MetricsProviderLifeCycleException error) { throw new IOException("Cannot boot MetricsProvider " + config.getMetricsProviderClassName(), error); } try { ServerMetrics.metricsProviderInitialized(metricsProvider); ServerCnxnFactory cnxnFactory = null; ServerCnxnFactory secureCnxnFactory = null; if (config.getClientPortAddress() != null) { cnxnFactory = ServerCnxnFactory.createFactory(); cnxnFactory.configure(config.getClientPortAddress(), config.getMaxClientCnxns(), config.getClientPortListenBacklog(), false); } if (config.getSecureClientPortAddress() != null) { secureCnxnFactory = ServerCnxnFactory.createFactory(); secureCnxnFactory.configure(config.getSecureClientPortAddress(), config.getMaxClientCnxns(), config.getClientPortListenBacklog(), true); } quorumPeer = getQuorumPeer(); quorumPeer.setTxnFactory(new FileTxnSnapLog(config.getDataLogDir(), config.getDataDir())); quorumPeer.enableLocalSessions(config.areLocalSessionsEnabled()); quorumPeer.enableLocalSessionsUpgrading(config.isLocalSessionsUpgradingEnabled()); //quorumPeer.setQuorumPeers(config.getAllMembers()); quorumPeer.setElectionType(config.getElectionAlg()); quorumPeer.setMyid(config.getServerId()); quorumPeer.setTickTime(config.getTickTime()); quorumPeer.setMinSessionTimeout(config.getMinSessionTimeout()); quorumPeer.setMaxSessionTimeout(config.getMaxSessionTimeout()); quorumPeer.setInitLimit(config.getInitLimit()); quorumPeer.setSyncLimit(config.getSyncLimit()); quorumPeer.setConnectToLearnerMasterLimit(config.getConnectToLearnerMasterLimit()); quorumPeer.setObserverMasterPort(config.getObserverMasterPort()); quorumPeer.setConfigFileName(config.getConfigFilename()); quorumPeer.setClientPortListenBacklog(config.getClientPortListenBacklog()); quorumPeer.setZKDatabase(new ZKDatabase(quorumPeer.getTxnFactory())); quorumPeer.setQuorumVerifier(config.getQuorumVerifier(), false); if (config.getLastSeenQuorumVerifier() != null) { quorumPeer.setLastSeenQuorumVerifier(config.getLastSeenQuorumVerifier(), false); } quorumPeer.initConfigInZKDatabase(); quorumPeer.setCnxnFactory(cnxnFactory); quorumPeer.setSecureCnxnFactory(secureCnxnFactory); quorumPeer.setSslQuorum(config.isSslQuorum()); quorumPeer.setUsePortUnification(config.shouldUsePortUnification()); quorumPeer.setLearnerType(config.getPeerType()); quorumPeer.setSyncEnabled(config.getSyncEnabled()); quorumPeer.setQuorumListenOnAllIPs(config.getQuorumListenOnAllIPs()); if (config.sslQuorumReloadCertFiles) { quorumPeer.getX509Util().enableCertFileReloading(); } // sets quorum sasl authentication configurations quorumPeer.setQuorumSaslEnabled(config.quorumEnableSasl); if (quorumPeer.isQuorumSaslAuthEnabled()) { quorumPeer.setQuorumServerSaslRequired(config.quorumServerRequireSasl); quorumPeer.setQuorumLearnerSaslRequired(config.quorumLearnerRequireSasl); quorumPeer.setQuorumServicePrincipal(config.quorumServicePrincipal); quorumPeer.setQuorumServerLoginContext(config.quorumServerLoginContext); quorumPeer.setQuorumLearnerLoginContext(config.quorumLearnerLoginContext); } quorumPeer.setQuorumCnxnThreadsSize(config.quorumCnxnThreadsSize); quorumPeer.initialize(); if (config.jvmPauseMonitorToRun) { quorumPeer.setJvmPauseMonitor(new JvmPauseMonitor(config)); } quorumPeer.start(); ZKAuditProvider.addZKStartStopAuditLog(); quorumPeer.join(); } catch (InterruptedException e) { // warn, but generally this is ok LOG.warn("Quorum Peer interrupted", e); } finally { if (metricsProvider != null) { try { metricsProvider.stop(); } catch (Throwable error) { LOG.warn("Error while stopping metrics", error); } } } } // @VisibleForTesting protected QuorumPeer getQuorumPeer() throws SaslException { return new QuorumPeer(); } }