10-使用配置信息启动运行入口

在 QuorumPeerMain类型中前面我看了解了刚刚启动时候的配置加载,日志清理工具开启,接下来我们先回顾一下:

protected void initializeAndRun(String[] args) throws ConfigException, IOException, AdminServerException {
		//配置加载前面看过
        QuorumPeerConfig config = new QuorumPeerConfig();
        if (args.length == 1) {
            config.parse(args[0]);
        }

        // Start and schedule the the purge task
        //清理工具前面说过
        DatadirCleanupManager purgeMgr = new DatadirCleanupManager(
            config.getDataDir(),
            config.getDataLogDir(),
            config.getSnapRetainCount(),
            config.getPurgeInterval());
        purgeMgr.start();
		
		//分布式运行或者单机运行
        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);
        }
    }

使用配置运行分布式应用
启动代码如下根据参数判断单机启动还是分布式启动，这里我们主要看分布式启动一般产线我们部署的应用都是分布式的不会是单机来部署。

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);
}

上面主要做了初始化操作，接下来就是启动过程

• 1:如果存在配置参数并且也存在server参数则程序将使用配置来启动。
• 2:如果不存在配置参数则以独立程序模式来启动

使用配置启动过程runFromConfig我们先来review一下代码做了什么：

QuorumPeerMain类型的使用配置信息启动运行入口

public void runFromConfig(QuorumPeerConfig config) throws IOException, AdminServerException {
    try {
    	//log4jMBean
        ManagedUtil.registerLog4jMBeans();
    } catch (JMException e) {
        LOG.warn("Unable to register log4j JMX control", e);
    }

	//监控指标
    LOG.info("Starting quorum peer, myid=" + config.getServerId());
    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;

		//连接信息
        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);
        }

		//节点创建与配置初始化
        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();
        }
        quorumPeer.setMultiAddressEnabled(config.isMultiAddressEnabled());
        quorumPeer.setMultiAddressReachabilityCheckEnabled(config.isMultiAddressReachabilityCheckEnabled());
        quorumPeer.setMultiAddressReachabilityCheckTimeoutMs(config.getMultiAddressReachabilityCheckTimeoutMs());

        // 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);
        //节点初始化
        quorumPeer.initialize();

        if (config.jvmPauseMonitorToRun) {
            quorumPeer.setJvmPauseMonitor(new JvmPauseMonitor(config));
        }
		//节点启动
        quorumPeer.start();
        ZKAuditProvider.addZKStartStopAuditLog();
        //节点加入集群
        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);
            }
        }
    }
}

说下目前遇到的runFromConfig主流程主要如下:

• log4jMBean启动
• 监控指标启动
• 连接信息配置
• QuorumPeer节点对象创建
• QuorumPeer节点配置初始化
• QuorumPeer节点启动
• QuorumPeer节点加入集群

后续我们针对这个流程详细细说,可以继续关注后续博客

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