分布式定时任务elastic-job(一)

目录

分布式定时任务elastic-job(一)_第1张图片
目录.png

分布式定时任务系列

  • 分布式定时任务elastic-job(一)
  • 分布式定时任务elastic-job(二)
  • 分布式定时任务elastic-job(三)
  • 分布式定时任务elastic-job(四)

配置

客户端核心配置SpringJobScheduler

@Bean(initMethod = "init")
public JobScheduler simpleJobScheduler(final SimpleJob simpleJob,
                                       @Value("${simpleJob.cron}") final String cron,
                                       @Value("${simpleJob.shardingTotalCount}") final int shardingTotalCount,
                                       @Value("${simpleJob.shardingItemParameters}") final String shardingItemParameters,
                                       @Value("${simpleJob.jobParameter}") final String jobParameter,
                                       @Value("${simpleJob.failover}") final boolean failover,
                                       @Value("${simpleJob.monitorExecution}") final boolean monitorExecution,
                                       @Value("${simpleJob.monitorPort}") final int monitorPort,
                                       @Value("${simpleJob.maxTimeDiffSeconds}") final int maxTimeDiffSeconds,
                                       @Value("${simpleJob.jobShardingStrategyClass}") final String jobShardingStrategyClass) {
        // SpringJobScheduler配置,分析初始化从这里开始
    return new SpringJobScheduler(simpleJob,
            registryCenter,
            getLiteJobConfiguration(simpleJob.getClass(),
                    cron,
                    shardingTotalCount,
                    shardingItemParameters,
                    jobParameter,
                    failover,
                    monitorExecution,
                    monitorPort,
                    maxTimeDiffSeconds,
                    jobShardingStrategyClass),
            jobEventConfiguration,
            new SimpleJobListener());

}


private LiteJobConfiguration getLiteJobConfiguration(Class jobClass, String cron,
                                                     int shardingTotalCount, String shardingItemParameters, String jobParameter, boolean failover,
                                                     boolean monitorExecution, int monitorPort, int maxTimeDiffSeconds, String jobShardingStrategyClass) {

    //定义作业核心配置
    JobCoreConfiguration jobCoreConfiguration = JobCoreConfiguration
            .newBuilder(jobClass.getName(), cron, shardingTotalCount)
            .misfire(true)
            .failover(failover)
            .jobParameter(jobParameter)
            .shardingItemParameters(shardingItemParameters)
            .jobProperties("job_exception_handler", "com.seeger.demo.config.MyJobExceptionHandler")
            .build();

    //定义SIMPLE类型配置
    SimpleJobConfiguration simpleJobConfiguration = new SimpleJobConfiguration(jobCoreConfiguration, jobClass.getCanonicalName());

    //定义Lite作业根配置
    LiteJobConfiguration liteJobConfiguration = LiteJobConfiguration.newBuilder(simpleJobConfiguration)
            .jobShardingStrategyClass(jobShardingStrategyClass)
            .monitorExecution(monitorExecution)
            .monitorPort(monitorPort)
            .maxTimeDiffSeconds(maxTimeDiffSeconds)
            .overwrite(true)
            .build();

    return liteJobConfiguration;
}

SpringJobScheduler

  • 初始化代码
public JobScheduler(final CoordinatorRegistryCenter regCenter, final LiteJobConfiguration liteJobConfig, final JobEventConfiguration jobEventConfig, 
                    final ElasticJobListener... elasticJobListeners) {
    this(regCenter, liteJobConfig, new JobEventBus(jobEventConfig), elasticJobListeners);
}
    
private JobScheduler(final CoordinatorRegistryCenter regCenter, final LiteJobConfiguration liteJobConfig, final JobEventBus jobEventBus, final ElasticJobListener... elasticJobListeners) {
    JobRegistry.getInstance().addJobInstance(liteJobConfig.getJobName(), new JobInstance());
    this.liteJobConfig = liteJobConfig;
    this.regCenter = regCenter;
    List elasticJobListenerList = Arrays.asList(elasticJobListeners);
    setGuaranteeServiceForElasticJobListeners(regCenter, elasticJobListenerList);
    schedulerFacade = new SchedulerFacade(regCenter, liteJobConfig.getJobName(), elasticJobListenerList);
    jobFacade = new LiteJobFacade(regCenter, liteJobConfig.getJobName(), Arrays.asList(elasticJobListeners), jobEventBus);
}
  • 可以看到父类JobScheduler有几个属性LiteJobConfiguration(Lite作业配置),CoordinatorRegistryCenter(注册中心),SchedulerFacade,JobFacade


    分布式定时任务elastic-job(一)_第2张图片
    SpringJobScheduler对应diagram.png
LiteJobConfiguration
  • 作业配置类


    分布式定时任务elastic-job(一)_第3张图片
    作业配置类diagram.png
  1. typeConfig: 作业配置类型,分为simple,dataflow,script不同类型不同配置类


    分布式定时任务elastic-job(一)_第4张图片
    JobTypeConfiguration的diagram.png
  2. monitorExecution监控作业运行状态,如果执行时间与执行间隔都短的情况下不建议开启
  3. maxTimeDiffSeconds设置最大容忍的本机与注册中心的时间误差秒数
  4. monitorPort作业监控端口,可以dump文件,echo “dump” | nc 127.0.0.1 9888
  5. jobShardingStrategyClass策略模式实现分片的不同策略
  6. reconcileIntervalMinutes修复作业服务器不一致状态服务调度间隔时间
  7. disabled是否禁用
  8. overwrite使用本地作业配置覆盖注册中心的作业配置
  • JobTypeConfiguration,以最常用的SimpleJobConfiguration举例


    分布式定时任务elastic-job(一)_第5张图片
    SimpleJobConfiguration.png

    分布式定时任务elastic-job(一)_第6张图片
    JobCoreConfiguration.png
  1. jobName作业名称
  2. cron core表达式
  3. shardingTotalCount作业分片总数
  4. shardingItemParameters 分片项目参数,给分片上别名,本来分片是0,1,2,3这种的,可以起别名增加可读性
  5. jobParameter自定义作业参数
  6. failover失效转移是否启动,集群上别的集群如果有分片失效了比如这台服务宕机,可以让本机执行失效的分片,这里并不是master节点(可能每个任务都不同的master节点,因为主节点如果存在说明zk上有/${JOB_NAME}/leader/electron/instance,不同job就有可能存在不同的master节点)执行,而是任务争夺到分布式锁的机器执行,这里能够利用集群能力
  7. misfire错过执行 如果本机的任务时间间隔比执行时间短,那就错过了,elastic-job提供错过重执行的功能
  8. description描述
  9. jobProperties job属性,可以自定义异常处理器和线程池是SPI接口
CoordinatorRegistryCenter
  • 注册中心,用于协调分布式服务,提供了默认实现ZookeeperRegistryCenter。ZookeeperRegistryCenter定义了持久节点、临时节点、持久顺序节点、临时顺序节点等目录服务接口方法,隐性的要求提供事务、分布式锁、数据订阅等特。ZookeeperRegistryCenter封装了apaceh /curator(zk连接设置节点等,使用curator很方便)方法。elastic job使用 Quartz 作为调度内核。


    分布式定时任务elastic-job(一)_第7张图片
    注册中心配置.png
  • ZookeeperConfiguration,初始化方法, 根据设置的zk配置初始化curator框架的client。其中ExponentialBackoffRetry动态计算时间间隔
public void init() {
    log.debug("Elastic job: zookeeper registry center init, server lists is: {}.", zkConfig.getServerLists());
    CuratorFrameworkFactory.Builder builder = CuratorFrameworkFactory.builder()
            .connectString(zkConfig.getServerLists())
            .retryPolicy(new ExponentialBackoffRetry(zkConfig.getBaseSleepTimeMilliseconds(), zkConfig.getMaxRetries(), zkConfig.getMaxSleepTimeMilliseconds()))
            .namespace(zkConfig.getNamespace());
    if (0 != zkConfig.getSessionTimeoutMilliseconds()) {
        builder.sessionTimeoutMs(zkConfig.getSessionTimeoutMilliseconds());
    }
    if (0 != zkConfig.getConnectionTimeoutMilliseconds()) {
        builder.connectionTimeoutMs(zkConfig.getConnectionTimeoutMilliseconds());
    }
    if (!Strings.isNullOrEmpty(zkConfig.getDigest())) {
        builder.authorization("digest", zkConfig.getDigest().getBytes(Charsets.UTF_8))
                .aclProvider(new ACLProvider() {
                
                    @Override
                    public List getDefaultAcl() {
                        return ZooDefs.Ids.CREATOR_ALL_ACL;
                    }
                
                    @Override
                    public List getAclForPath(final String path) {
                        return ZooDefs.Ids.CREATOR_ALL_ACL;
                    }
                });
    }
    client = builder.build();
    client.start();
    try {
        if (!client.blockUntilConnected(zkConfig.getMaxSleepTimeMilliseconds() * zkConfig.getMaxRetries(), TimeUnit.MILLISECONDS)) {
            client.close();
            throw new KeeperException.OperationTimeoutException();
        }
        //CHECKSTYLE:OFF
    } catch (final Exception ex) {
        //CHECKSTYLE:ON
        RegExceptionHandler.handleException(ex);
    }
}
// 动态计算时间间隔
baseSleepTimeMs * Math.max(1, random.nextInt(1 << (retryCount + 1)))
  • 缓存是通过 Curator TreeCache 实现监控整个树( Zookeeper目录 )的数据订阅和缓存
  • 对zk的crud比较基础细节可以深入源码看
SchedulerFacade
  • 通过调用构造器
public JobScheduler(final CoordinatorRegistryCenter regCenter, final LiteJobConfiguration liteJobConfig, final JobEventConfiguration jobEventConfig, 
                    final ElasticJobListener... elasticJobListeners) {
    this(regCenter, liteJobConfig, new JobEventBus(jobEventConfig), elasticJobListeners);
}
    
private JobScheduler(final CoordinatorRegistryCenter regCenter, final LiteJobConfiguration liteJobConfig, final JobEventBus jobEventBus, final ElasticJobListener... elasticJobListeners) {
    // 省去部分代码
    schedulerFacade = new SchedulerFacade(regCenter, liteJobConfig.getJobName(), elasticJobListenerList);
}

// 调用SchedulerFacade
 public SchedulerFacade(final CoordinatorRegistryCenter regCenter, final String jobName, final List elasticJobListeners) {
        this.jobName = jobName;
        configService = new ConfigurationService(regCenter, jobName);
        leaderService = new LeaderService(regCenter, jobName);
        serverService = new ServerService(regCenter, jobName);
        instanceService = new InstanceService(regCenter, jobName);
        shardingService = new ShardingService(regCenter, jobName);
        executionService = new ExecutionService(regCenter, jobName);
        monitorService = new MonitorService(regCenter, jobName);
        reconcileService = new ReconcileService(regCenter, jobName);
        listenerManager = new ListenerManager(regCenter, jobName, elasticJobListeners);
    }
  • 为调度器提供内部服务的门面类,包含各个service


    分布式定时任务elastic-job(一)_第8张图片
    为调度器提供内部服务的门面类
  • ElasticJobListeners监听器是放到ListenerManager做管理
  • 可以看到各个service都是基于regCenter, jobName做初始化
JobFacade
  • 通过调用构造器初始化
public JobScheduler(final CoordinatorRegistryCenter regCenter, final LiteJobConfiguration liteJobConfig, final JobEventConfiguration jobEventConfig, 
                        final ElasticJobListener... elasticJobListeners) {
    this(regCenter, liteJobConfig, new JobEventBus(jobEventConfig), elasticJobListeners);
}
private JobScheduler(final CoordinatorRegistryCenter regCenter, final LiteJobConfiguration liteJobConfig, final JobEventBus jobEventBus, final ElasticJobListener... elasticJobListeners) {
    // 省略部分代码
    jobFacade = new LiteJobFacade(regCenter, liteJobConfig.getJobName(), Arrays.asList(elasticJobListeners), jobEventBus);
}
// 调用LiteJobFacade构造器
public LiteJobFacade(final CoordinatorRegistryCenter regCenter, final String jobName, final List elasticJobListeners, final JobEventBus jobEventBus) {
    configService = new ConfigurationService(regCenter, jobName);
    shardingService = new ShardingService(regCenter, jobName);
    executionContextService = new ExecutionContextService(regCenter, jobName);
    executionService = new ExecutionService(regCenter, jobName);
    failoverService = new FailoverService(regCenter, jobName);
    this.elasticJobListeners = elasticJobListeners;
    this.jobEventBus = jobEventBus;
}
  • 为Job提供内部服务的门面类, 包含各个service, 以及event bus


    分布式定时任务elastic-job(一)_第9张图片
    为Job提供内部服务的门面类.png
  • 初始化时会传设置好的JobEventConfiguration,通过new JobEventBus(jobEventConfig)设置JobEventBus。
  • 监听器是LiteJobFacade自个管理
  • 可以看到各个service都是基于regCenter, jobName做初始化

事件追踪配置JobEventConfiguration

@Autowired
private DataSource dataSource;

@Bean
public JobEventConfiguration jobEventConfiguration() {
    return new JobEventRdbConfiguration(dataSource);
}
  • 初始化的类比较简单
public final class JobEventRdbConfiguration extends JobEventRdbIdentity implements JobEventConfiguration, Serializable {
    private static final long serialVersionUID = 3344410699286435226L;
    private final transient DataSource dataSource;

    public JobEventListener createJobEventListener() throws JobEventListenerConfigurationException {
        try {
            return new JobEventRdbListener(this.dataSource);
        } catch (SQLException var2) {
            throw new JobEventListenerConfigurationException(var2);
        }
    }
   // 初始化时调用
    @ConstructorProperties({"dataSource"})
    public JobEventRdbConfiguration(DataSource dataSource) {
        this.dataSource = dataSource;
    }

    public DataSource getDataSource() {
        return this.dataSource;
    }
}

JobRegistry作业注册表

  • 调用构造函数构造SpringJobScheduler时,会往JobRegistry注册
public JobScheduler(final CoordinatorRegistryCenter regCenter, final LiteJobConfiguration liteJobConfig, final JobEventConfiguration jobEventConfig, 
                    final ElasticJobListener... elasticJobListeners) {
    this(regCenter, liteJobConfig, new JobEventBus(jobEventConfig), elasticJobListeners);
}
    
private JobScheduler(final CoordinatorRegistryCenter regCenter, final LiteJobConfiguration liteJobConfig, final JobEventBus jobEventBus, final ElasticJobListener... elasticJobListeners) {
    JobRegistry.getInstance().addJobInstance(liteJobConfig.getJobName(), new JobInstance());
    // 省略部分代码
}
// getInstance单例
 public static JobRegistry getInstance() {
    if (null == instance) {
        synchronized (JobRegistry.class) {
            if (null == instance) {
                instance = new JobRegistry();
            }
        }
    }
    return instance;
}
// addJobInstance
public void addJobInstance(final String jobName, final JobInstance jobInstance) {
    jobInstanceMap.put(jobName, jobInstance);
}
  • JobRegistry是单例,设计思想有点类似spring ioc容器


    分布式定时任务elastic-job(一)_第10张图片
    JobRegistry.png
  • instance: 单例 private static volatile JobRegistry 修饰
  • 各个map缓存数据,ConcurrentHashMap保证单个put并发安全

初始化

  • 调用完构造函数后,会调用init方法
@Bean(initMethod = "init")
public JobScheduler simpleJobScheduler(//省略参数) {
    return new SpringJobScheduler(省略参数);
}
  • 调用init方法
public void init() {
    //更新作业配置
    LiteJobConfiguration liteJobConfigFromRegCenter = schedulerFacade.updateJobConfiguration(liteJobConfig);
    // 设置分片信息
    JobRegistry.getInstance().setCurrentShardingTotalCount(liteJobConfigFromRegCenter.getJobName(), liteJobConfigFromRegCenter.getTypeConfig().getCoreConfig().getShardingTotalCount());
    // 创建作业调度控制器
    JobScheduleController jobScheduleController = new JobScheduleController(
            createScheduler(), createJobDetail(liteJobConfigFromRegCenter.getTypeConfig().getJobClass()), liteJobConfigFromRegCenter.getJobName());
    // 添加作业调度控制器
    JobRegistry.getInstance().registerJob(liteJobConfigFromRegCenter.getJobName(), jobScheduleController, regCenter);
    // 注册启动信息
    schedulerFacade.registerStartUpInfo(!liteJobConfigFromRegCenter.isDisabled());
    // 调度作业,基于quartz
    jobScheduleController.scheduleJob(liteJobConfigFromRegCenter.getTypeConfig().getCoreConfig().getCron());
}

更新作业配置

  • SchedulerFacade门面里面ConfigService new出来的, ConfigService依赖JobNodeStorage,JobNodeStorage使用curator对zk操作
 public LiteJobConfiguration updateJobConfiguration(final LiteJobConfiguration liteJobConfig) {
    // 持久化
    configService.persist(liteJobConfig);
    // 读取配置
    return configService.load(false);
}

// ConfigService 
public void persist(final LiteJobConfiguration liteJobConfig) {
    checkConflictJob(liteJobConfig);
    if (!jobNodeStorage.isJobNodeExisted(ConfigurationNode.ROOT) || liteJobConfig.isOverwrite()) {
        jobNodeStorage.replaceJobNode(ConfigurationNode.ROOT, LiteJobConfigurationGsonFactory.toJson(liteJobConfig));
    }
}

设置作业分片

  • SchedulerFacade门面里面JobRegistry.getInstance().setCurrentShardingTotalCount
private Map currentShardingTotalCountMap = new ConcurrentHashMap<>();

public void setCurrentShardingTotalCount(final String jobName, final int currentShardingTotalCount) {
    currentShardingTotalCountMap.put(jobName, currentShardingTotalCount);
}

创建作业调度控制器

  • JobScheduleController作业调度控制器,提供对Quartz的封装,
JobScheduleController jobScheduleController = new JobScheduleController(
                createScheduler(), createJobDetail(liteJobConfigFromRegCenter.getTypeConfig().getJobClass()), liteJobConfigFromRegCenter.getJobName());
createScheduler
  • org.quartz.threadPool.threadCount这里配置1,Quartz 执行作业线程数量为 1, 一个ElasticJob对应1个JobScheduler作业调度器,失效转移时会调用quartz的trigger,有可能多次调用,这个时候因为Quartz 执行作业线程数设置为1,所以是串行执行,不会有并发问题。
 // 创建quartz调度器
 private Scheduler createScheduler() {
    Scheduler result;
    try {
        // quartz提供的能力创建Scheduler
        StdSchedulerFactory factory = new StdSchedulerFactory();
        factory.initialize(getBaseQuartzProperties());
        result = factory.getScheduler();
        result.getListenerManager().addTriggerListener(schedulerFacade.newJobTriggerListener());
    } catch (final SchedulerException ex) {
        throw new JobSystemException(ex);
    }
    return result;
}

private Properties getBaseQuartzProperties() {
    Properties result = new Properties();
    result.put("org.quartz.threadPool.class", org.quartz.simpl.SimpleThreadPool.class.getName());
    // Quartz 执行作业线程数量为 1, 一个ElasticJob对应1个JobScheduler作业调度器
    result.put("org.quartz.threadPool.threadCount", "1");
    result.put("org.quartz.scheduler.instanceName", liteJobConfig.getJobName());
    result.put("org.quartz.jobStore.misfireThreshold", "1");
    result.put("org.quartz.plugin.shutdownhook.class", JobShutdownHookPlugin.class.getName());
    result.put("org.quartz.plugin.shutdownhook.cleanShutdown", Boolean.TRUE.toString());
    return result;
}
createJobDetail
  • 创建JobDetail时使用newJob(LiteJob.class),每次任务都会new LiteJob,Jodetail.jobDataMap为LiteJob添加属性,这样虽然每次都是new的LiteJob, 但是每次属性是一样的。
private JobDetail createJobDetail(final String jobClass) {
    // quartz的能力,创建JobDetail
    JobDetail result = JobBuilder.newJob(LiteJob.class).withIdentity(liteJobConfig.getJobName()).build();
    result.getJobDataMap().put(JOB_FACADE_DATA_MAP_KEY, jobFacade);
    // 创建ElasticJob对象
    Optional elasticJobInstance = createElasticJobInstance();
    if (elasticJobInstance.isPresent()) {
        result.getJobDataMap().put(ELASTIC_JOB_DATA_MAP_KEY, elasticJobInstance.get());
    } else if (!jobClass.equals(ScriptJob.class.getCanonicalName())) {
        try {
            result.getJobDataMap().put(ELASTIC_JOB_DATA_MAP_KEY, Class.forName(jobClass).newInstance());
        } catch (final ReflectiveOperationException ex) {
            throw new JobConfigurationException("Elastic-Job: Job class '%s' can not initialize.", jobClass);
        }
    }
    return result;
}
注册作业启动信息
  • SchedulerFacade里面调用注册作业启动信息
public void registerStartUpInfo(final boolean enabled) {
    // 开启所有监听器
    listenerManager.startAllListeners();
    // 选主
    leaderService.electLeader();
    // zk持久化作业服务信息
    serverService.persistOnline(enabled);
    // zk持久化作业运行实例上线相关信息
    instanceService.persistOnline();
    // 在zk上设置需要重新分片的标注,新上线服务,后面会分析分片
    shardingService.setReshardingFlag();
    // 初始化作业监听服务,这个在后面自诊断修复会涉及
    monitorService.listen();
    // 初始化调解作业不一致状态服务
    if (!reconcileService.isRunning()) {
        reconcileService.startAsync();
    }
}
作业调度
public void init() {
   // 进行作业调度 利用quartz
   jobScheduleController.scheduleJob(liteJobConfigFromRegCenter.getTypeConfig().getCoreConfig().getCron());
}

初始化与执行联系

quartz简单介绍

  • 核心元素有四个
  1. Trigger: 触发器用于定义时间规则,比如core表达式的触发
  2. Job: 任务执行的逻辑
  3. JobDetail: 任务详情
  4. Scheduler: 调度控制器
  • 借用参考文章6的图


    分布式定时任务elastic-job(一)_第11张图片
    quartz核心元素.png
  • quartz有两种线程类型,一种是常规执行任务线程,一种是错过执行线程,当任务触发时间小于任务执行时间时,就会标记错过的任务,这个时候elastic-job将quartz错过执行的逻辑转移到elastic-job框架处理

初始化与执行的联系

  • 在初始化时创建JobDetail,JobBuilder.newJob(LiteJob.class),每次执行会new LiteJob,并且设置属性进行,属性里面的值每次都是同一实例
private JobDetail createJobDetail(final String jobClass) {
    // quartz的能力,创建JobDetail
    JobDetail result = JobBuilder.newJob(LiteJob.class).withIdentity(liteJobConfig.getJobName()).build();
    result.getJobDataMap().put(JOB_FACADE_DATA_MAP_KEY, jobFacade);
}
  • 任务触发之后会执行LiteJob.execute方法
public final class LiteJob implements Job {
    
    @Override
    public void execute(final JobExecutionContext context) throws JobExecutionException {
        JobExecutorFactory.getJobExecutor(elasticJob, jobFacade).execute();
    }
}

// JobExecutorFactory
// 这里是策略模式的Context,根据不同输入,获取不同实例,有脚本job simple job和data flow job
public static AbstractElasticJobExecutor getJobExecutor(final ElasticJob elasticJob, final JobFacade jobFacade) {
    if (null == elasticJob) {
        return new ScriptJobExecutor(jobFacade);
    }
    if (elasticJob instanceof SimpleJob) {
        return new SimpleJobExecutor((SimpleJob) elasticJob, jobFacade);
    }
    if (elasticJob instanceof DataflowJob) {
        return new DataflowJobExecutor((DataflowJob) elasticJob, jobFacade);
    }
    throw new JobConfigurationException("Cannot support job type '%s'", elasticJob.getClass().getCanonicalName());
}
  • 到AbstractElasticJobExecutor.executor是几个Job Executor的父类,executor这块代码也是elastic-job核心的代码


    分布式定时任务elastic-job(一)_第12张图片
    AbstractElasticJobExecutor子类.png

参考文章

  1. 脑裂是什么?Zookeeper是如何解决的?
  2. Kafka研究系列之kafka 如何避免脑裂?如何选举leader
  3. 如何防止ElasticSearch集群出现脑裂现象
  4. elastic-job调度模型
  5. 芋道源码-elastic-job
  6. Quartz原理解密
  7. 分布式定时任务调度系统技术选型

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