版本：3.1.0-SNAPSHOT
git地址：https://github.com/apache/shardingsphere-elasticjob
Maven 坐标
<dependency>
<groupId>org.apache.shardingsphere.elasticjob</groupId>
<artifactId>elasticjob-lite-spring-boot-starter</artifactId>
<version>${latest.version}</version>
</dependency>
Spring.factories配置
org.springframework.boot.autoconfigure.EnableAutoConfiguration=\
org.apache.shardingsphere.elasticjob.lite.spring.boot.job.ElasticJobLiteAutoConfiguration
在添加elasticjob-lite-spring-boot-starter启动类的时候，会自动加载ElasticJobLiteAutoConfiguration，接下来看下ElasticJobLiteAutoConfiguration中所做的处理。
ElasticJobLiteAutoConfiguration.java
/**
* ElasticJob-Lite auto configuration.
*/
@Configuration(proxyBeanMethods = false)
@AutoConfigureAfter(DataSourceAutoConfiguration.class) /**
* elastic job 开关
* elasticjob.enabled.ture默认为true
*/
@ConditionalOnProperty(name = "elasticjob.enabled", havingValue = "true", matchIfMissing = true) /**
* 导入
* ElasticJobRegistryCenterConfiguration.class 注册中心配置
* ElasticJobTracingConfiguration.class job事件追踪配置
* ElasticJobSnapshotServiceConfiguration.class 快照配置
*/
@Import({ElasticJobRegistryCenterConfiguration.class, ElasticJobTracingConfiguration.class, ElasticJobSnapshotServiceConfiguration.class}) /**
* job相关配置信息
*/
@EnableConfigurationProperties(ElasticJobProperties.class)
public class ElasticJobLiteAutoConfiguration { @Configuration(proxyBeanMethods = false)
/**
* ElasticJobBootstrapConfiguration.class 创建job beans 注入spring容器
* ScheduleJobBootstrapStartupRunner.class 执行类型为ScheduleJobBootstrap.class 的job开始运行
*/
@Import({ElasticJobBootstrapConfiguration.class, ScheduleJobBootstrapStartupRunner.class})
protected static class ElasticJobConfiguration {
}
}
Elastic-job 是利用zookeeper 实现分布式job的功能，所以在自动装配的时候，需要有zookeeper注册中心的配置。
自动装配主要做了4件事事
1.配置zookeeper 客户端信息，启动连接zookeeper.
2.配置事件追踪数据库，用于保存job运行记录
3.解析所有job配置文件，将所有job的bean放置在spring 单例bean中
4.识别job类型，在zookeeper节点上处理job节点数据，运行定时任务job.
第一件事：配置zookeeper 客户端信息，启动连接zookeeper.
ZookeeperRegistryCenter.class
public void init() {
log.debug("Elastic job: zookeeper registry center init, server lists is: {}.", zkConfig.getServerLists());
CuratorFrameworkFactory.Builder builder = CuratorFrameworkFactory.builder()
//设置zookeeper 服务器地址
.connectString(zkConfig.getServerLists())
//设置重试机制
.retryPolicy(new ExponentialBackoffRetry(zkConfig.getBaseSleepTimeMilliseconds(), zkConfig.getMaxRetries(), zkConfig.getMaxSleepTimeMilliseconds()))
//设置命名空间，zookeeper节点名称
.namespace(zkConfig.getNamespace());
//设置session超时时间
if (0 != zkConfig.getSessionTimeoutMilliseconds()) {
builder.sessionTimeoutMs(zkConfig.getSessionTimeoutMilliseconds());
}
//设置连接超时时间
if (0 != zkConfig.getConnectionTimeoutMilliseconds()) {
builder.connectionTimeoutMs(zkConfig.getConnectionTimeoutMilliseconds());
}
if (!Strings.isNullOrEmpty(zkConfig.getDigest())) {
builder.authorization("digest", zkConfig.getDigest().getBytes(StandardCharsets.UTF_8))
.aclProvider(new ACLProvider() {
@Override
public List<ACL> getDefaultAcl() {
return ZooDefs.Ids.CREATOR_ALL_ACL;
}
@Override
public List<ACL> getAclForPath(final String path) {
return ZooDefs.Ids.CREATOR_ALL_ACL;
}
});
}
client = builder.build();
//zookeeper 客户端开始启动
client.start();
try {
//zookeeper 客户端一直连接
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);
}
}
第二件事： 配置事件追踪数据库，用于保存job运行记录
ElasticJobTracingConfiguration.java
/**
* Create a bean of tracing DataSource.
*
* @param tracingProperties tracing Properties
* @return tracing DataSource
*/
@Bean("tracingDataSource")
//spring中注入bean name 为tracingDataSource的job数据库连接信息
public DataSource tracingDataSource(final TracingProperties tracingProperties) {
//获取elastic-job 数据库配置
DataSourceProperties dataSource = tracingProperties.getDataSource();
if (dataSource == null) {
return null;
}
HikariDataSource tracingDataSource = new HikariDataSource();
tracingDataSource.setJdbcUrl(dataSource.getUrl());
BeanUtils.copyProperties(dataSource, tracingDataSource);
return tracingDataSource;
} /**
* Create a bean of tracing configuration.
*
* @param dataSource required by constructor
* @param tracingDataSource tracing ataSource
* @return a bean of tracing configuration
*/
@Bean
@ConditionalOnBean(DataSource.class)
@ConditionalOnProperty(name = "elasticjob.tracing.type", havingValue = "RDB")
public TracingConfiguration<DataSource> tracingConfiguration(final DataSource dataSource, @Nullable final DataSource tracingDataSource) {
/**
* dataSource 是业务数据库
* tracingDataSource 是job数据库
* 当配置elasticjob.tracing.type = RDB时，如果单独配置job数据库是，默认使用job数据库作为job运行轨迹的记录
* 但这边同时业务数据库和job追踪数据库同时注入是，mybatis-plus 结合@Table 使用的时候，很有可能找不到正确对应的数据源
*/
DataSource ds = tracingDataSource;
if (ds == null) {
ds = dataSource;
}
return new TracingConfiguration<>("RDB", ds);
}
通过elasticjob.tracing.type=RDB的配置开启事件追踪功能，这边job的事件追踪数据源可以和业务数据源配置不一样。
第三件事：解析所有job配置文件
ElasticJobBootstrapConfiguration.class
public void createJobBootstrapBeans() {
//获取job配置
ElasticJobProperties elasticJobProperties = applicationContext.getBean(ElasticJobProperties.class);
//获取单利注册对象
SingletonBeanRegistry singletonBeanRegistry = ((ConfigurableApplicationContext) applicationContext).getBeanFactory();
//获取注入zookeeper 客户端
CoordinatorRegistryCenter registryCenter = applicationContext.getBean(CoordinatorRegistryCenter.class);
//获取job事件追踪
TracingConfiguration<?> tracingConfig = getTracingConfiguration();
//构造JobBootstraps
constructJobBootstraps(elasticJobProperties, singletonBeanRegistry, registryCenter, tracingConfig);
}
重要的是constructJobBootstraps 这个方法，来看下
private void constructJobBootstraps(final ElasticJobProperties elasticJobProperties, final SingletonBeanRegistry singletonBeanRegistry,
final CoordinatorRegistryCenter registryCenter, final TracingConfiguration<?> tracingConfig) {
//遍历配置的每一个job
for (Map.Entry<String, ElasticJobConfigurationProperties> entry : elasticJobProperties.getJobs().entrySet()) {
ElasticJobConfigurationProperties jobConfigurationProperties = entry.getValue();
//校验 job class 和 type 都为空抛异常
Preconditions.checkArgument(null != jobConfigurationProperties.getElasticJobClass()
|| !Strings.isNullOrEmpty(jobConfigurationProperties.getElasticJobType()),
"Please specific [elasticJobClass] or [elasticJobType] under job configuration.");
//校验 job class 和 type 都有 报相互排斥
Preconditions.checkArgument(null == jobConfigurationProperties.getElasticJobClass()
|| Strings.isNullOrEmpty(jobConfigurationProperties.getElasticJobType()),
"[elasticJobClass] and [elasticJobType] are mutually exclusive."); if (null != jobConfigurationProperties.getElasticJobClass()) {
//通过class 注入job
registerClassedJob(entry.getKey(), entry.getValue().getJobBootstrapBeanName(), singletonBeanRegistry, registryCenter, tracingConfig, jobConfigurationProperties);
} else if (!Strings.isNullOrEmpty(jobConfigurationProperties.getElasticJobType())) {
//通过type 注入job
registerTypedJob(entry.getKey(), entry.getValue().getJobBootstrapBeanName(), singletonBeanRegistry, registryCenter, tracingConfig, jobConfigurationProperties);
}
}
}
Job 有两种类型的注入，第一种是是class,配置成job的全路径信息注入
再来看看registerClassedJob 方法里的内容
private void registerClassedJob(final String jobName, final String jobBootstrapBeanName, final SingletonBeanRegistry singletonBeanRegistry, final CoordinatorRegistryCenter registryCenter,
final TracingConfiguration<?> tracingConfig, final ElasticJobConfigurationProperties jobConfigurationProperties) {
//获取job配置
JobConfiguration jobConfig = jobConfigurationProperties.toJobConfiguration(jobName);
//配置job事件追踪
jobExtraConfigurations(jobConfig, tracingConfig);
//获取job类型
ElasticJob elasticJob = applicationContext.getBean(jobConfigurationProperties.getElasticJobClass());
//没有配置cron表达式 就初始化为OneOffJobBootstrap对象，一次性任务
if (Strings.isNullOrEmpty(jobConfig.getCron())) {
Preconditions.checkArgument(!Strings.isNullOrEmpty(jobBootstrapBeanName), "The property [jobBootstrapBeanName] is required for One-off job.");
singletonBeanRegistry.registerSingleton(jobBootstrapBeanName, new OneOffJobBootstrap(registryCenter, elasticJob, jobConfig));
} else {
//有配置cron表达式 就初始化为ScheduleJobBootstrap对象，定时任务
//设置bean name
String beanName = !Strings.isNullOrEmpty(jobBootstrapBeanName) ? jobBootstrapBeanName : jobConfig.getJobName() + "ScheduleJobBootstrap";
//注入ScheduleJobBootstrap对象为单利对象
singletonBeanRegistry.registerSingleton(beanName, new ScheduleJobBootstrap(registryCenter, elasticJob, jobConfig));
}
}
Class 类型注入的job有两种类型
1.ScheduleJobBootstrap：定时任务类型的job。
2.OneOffJobBootstrap：一定次job类型。
看下定义的new ScheduleJobBootstrap 方法
public JobScheduler(final CoordinatorRegistryCenter regCenter, final ElasticJob elasticJob, final JobConfiguration jobConfig) {
Preconditions.checkArgument(null != elasticJob, "Elastic job cannot be null.");
this.regCenter = regCenter;
//获取job监听器
Collection<ElasticJobListener> jobListeners = getElasticJobListeners(jobConfig);
// 集成所有操作zookeeper 节点的services,job 监听器
setUpFacade = new SetUpFacade(regCenter, jobConfig.getJobName(), jobListeners);
//获取当前job名称
String jobClassName = JobClassNameProviderFactory.getProvider().getJobClassName(elasticJob);
//zookeeper节点 {namespace}/{jobclassname}/config 放置job配置信息
this.jobConfig = setUpFacade.setUpJobConfiguration(jobClassName, jobConfig);
// 集成所有操作zookeeper 节点的services
schedulerFacade = new SchedulerFacade(regCenter, jobConfig.getJobName());
jobFacade = new LiteJobFacade(regCenter, jobConfig.getJobName(), jobListeners, findTracingConfiguration().orElse(null));
//检验job配置
validateJobProperties();
//定义job执行器
jobExecutor = new ElasticJobExecutor(elasticJob, this.jobConfig, jobFacade);
//监听器里注入GuaranteeService
setGuaranteeServiceForElasticJobListeners(regCenter, jobListeners);
//创建定时任务，开始执行
jobScheduleController = createJobScheduleController();
}
看下createJobScheduleController
private JobScheduleController createJobScheduleController() {
JobScheduleController result = new JobScheduleController(createScheduler(), createJobDetail(), getJobConfig().getJobName());
//注册job
JobRegistry.getInstance().registerJob(getJobConfig().getJobName(), result);
//注册器开始运行
registerStartUpInfo();
return result;
}
看下registerStartUpInfo方法
public void registerStartUpInfo(final boolean enabled) {
//开始所有的监听器
listenerManager.startAllListeners();
//选举leader /{namespace}/leader/election/instance 放置选举出来的服务器
leaderService.electLeader();
//{namespace}/{ipservers} 设置enable处理
serverService.persistOnline(enabled);
//临时节点 /{namespave}/instances 放置运行服务实例信息
instanceService.persistOnline();
//开启一个异步服务
if (!reconcileService.isRunning()) {
reconcileService.startAsync();
}
}
这里实行的操作：
1.开启所有监听器处理
2.leader选举
3.持久化节点数据
4.开启异步服务
第四步：4.识别job类型，在zookeeper节点上处理job节点数据，运行定时任务job.
@Override
public void run(final String... args) {
log.info("Starting ElasticJob Bootstrap.");
applicationContext.getBeansOfType(ScheduleJobBootstrap.class).values().forEach(ScheduleJobBootstrap::schedule);
log.info("ElasticJob Bootstrap started.");
}
获取到所有的定时任务job(ScheduleJobBootstrap类型)，执行schedule方法，底层实际使用quartz框架运行定时任务。
