Retro Eye care Haitian Deep Dark Default

ElasticJob provides a customized Spring Boot Starter, which can be used in conjunction with Spring Boot. Developers are free from configuring CoordinatorRegistryCenter, JobBootstrap by using ElasticJob Spring Boot Starter. What developers need to solve distributed scheduling problem are job implementations with a little configuration.

The following content is only demonstrated through Spring Boot 3. The relevant content may still be valid on Spring Boot 2, but since Spring Boot 2 has ended maintenance, no availability assumptions are made for Spring Boot 2.

Job configuration

Implements ElasticJob

Job implementation is similar to other usage of ElasticJob. The difference is that jobs will be registered into the Spring IoC container.

Thread-Safety Issue

Bean is singleton by default. Consider setting Bean Scope to prototype if the instance of ElasticJob would be used by more than a JobBootstrap.

@Component
public class SpringBootDataflowJob implements DataflowJob<Foo> {
    
    @Override
    public List<Foo> fetchData(final ShardingContext shardingContext) {
        // fetch data
    }
    
    @Override
    public void processData(final ShardingContext shardingContext, final List<Foo> data) {
        // process data
    }
}

Configure CoordinateRegistryCenter and Jobs

Configure the Zookeeper which will be used by ElasticJob via configuration files.

elasticjob.jobs is a Map. Using key as job name. Specific job type and configuration in value. The Starter will create instances of OneOffJobBootstrap or ScheduleJobBootstrap and register them into the Spring IoC container automatically.

Configuration reference:

elasticjob:
  regCenter:
    serverLists: localhost:6181
    namespace: elasticjob-springboot
  jobs:
    dataflowJob:
      elasticJobClass: org.apache.shardingsphere.elasticjob.dataflow.job.DataflowJob
      cron: 0/5 * * * * ?
      shardingTotalCount: 3
      shardingItemParameters: 0=Beijing,1=Shanghai,2=Guangzhou
    scriptJob:
      elasticJobType: SCRIPT
      cron: 0/10 * * * * ?
      shardingTotalCount: 3
      props:
        script.command.line: "echo SCRIPT Job: "

Configure jobs with annotation

As an alternative to elasticjob.jobs properties, declare job configuration with @ElasticJobConfiguration and enable scanning with @ElasticJobScan. The scanner creates ScheduleJobBootstrap (when cron is set) or OneOffJobBootstrap (when cron is empty) automatically.

@Component
@ElasticJobConfiguration(
        jobName = "annotationSimpleJob",
        cron = "0/5 * * * * ?",
        shardingTotalCount = 3,
        shardingItemParameters = "0=Beijing,1=Shanghai,2=Guangzhou")
public class AnnotationSimpleJob implements SimpleJob {
    
    @Override
    public void execute(final ShardingContext shardingContext) {
        // do something
    }
}

Enable scanning. Both value and basePackages accept base packages to scan:

@Configuration
@ElasticJobScan(basePackages = "org.example.job")
public class ElasticJobConfig {
}

Notes:

  • The bootstrap bean name defaults to the jobName, which must differ from the scanned job bean name. A non-empty cron creates a ScheduleJobBootstrap which is scheduled automatically on startup; an empty cron creates a OneOffJobBootstrap which must be triggered manually.
  • registryCenter optionally specifies the CoordinatorRegistryCenter bean name. When empty, the single CoordinatorRegistryCenter bean in the context is injected by type.
  • Job configuration is resolved at runtime from the annotation (with superclass fallback for CGLIB proxies). Only bean references are registered so bean definitions stay Spring AOT friendly, and the annotation types are covered by GraalVM reachability metadata for native images.
  • Annotation attributes cover timeZone, jobParameter, monitorExecution, failover, misfire, maxTimeDiffSeconds, reconcileIntervalMinutes, jobShardingStrategyType, jobExecutorThreadPoolSizeProviderType, jobErrorHandlerType, jobListenerTypes, extraConfigurations, description, props, disabled, overwrite, label, staticSharding, maxWaitMillis.

Job Start

Schedule Job

Just start Spring Boot Starter directly. The schedule jobs will startup when the Spring Boot Application is started.

One-off Job

When to execute OneOffJob is up to you. Developers can inject the OneOffJobBootstrap bean into where they plan to invoke. Trigger the job by invoking execute() method manually.

Users should not use annotations such as jakarta.annotation.Resource which partially violate Spring Boot best practices to inject Spring beans that define one-time tasks.

The bean name of OneOffJobBootstrap is specified by property “jobBootstrapBeanName”, Please refer to Spring Boot Starter Configuration.

elasticjob:
  jobs:
    myOneOffJob:
      elasticJobType: SCRIPT
      jobBootstrapBeanName: myOneOffJobBean
      shardingTotalCount: 9
      props:
        script.command.line: "echo Manual SCRIPT Job: "

import org.apache.shardingsphere.elasticjob.bootstrap.type.OneOffJobBootstrap;
import org.springframework.beans.factory.ObjectProvider;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.Objects;

@RestController
public class OneOffJobController {
    // Injection via "@Autowired"
    @Autowired
    @Qualifier("myOneOffJobBean")
    private ObjectProvider<OneOffJobBootstrap> myOneOffJobProvider;

    @GetMapping("/execute2")
    public String executeOneOffJob2() {
        OneOffJobBootstrap myOneOffJob = myOneOffJobProvider.getIfAvailable();
        Objects.requireNonNull(myOneOffJob);
        myOneOffJob.execute();
        return "{\"msg\":\"OK\"}";
    }
}

Configuration error handler strategy

In the process of using ElasticJob, when the job is abnormal, the following error handling strategies can be used.

Error handler strategy name Description Built-in Default Extra config
Log Strategy Log error and do not interrupt job Yes Yes
Throw Strategy Throw system exception and interrupt job Yes
Ignore Strategy Ignore exception and do not interrupt job Yes
Email Notification Strategy Send email message notification and do not interrupt job Yes
Wechat Enterprise Notification Strategy Send wechat message notification and do not interrupt job Yes
Dingtalk Notification Strategy Send dingtalk message notification and do not interrupt job Yes

Log Strategy

elasticjob:
  regCenter:
    ...
  jobs:
    ...
    jobErrorHandlerType: LOG

Throw Strategy

elasticjob:
  regCenter:
    ...
  jobs:
    ...
    jobErrorHandlerType: THROW

Ignore Strategy

elasticjob:
  regCenter:
    ...
  jobs:
    ...
    jobErrorHandlerType: IGNORE

Email Notification Strategy

Please refer to here for more details.

Maven POM:

<dependency>
    <groupId>org.apache.shardingsphere.elasticjob</groupId>
    <artifactId>elasticjob-error-handler-email</artifactId>
    <version>${latest.release.version}</version>
</dependency>

elasticjob:
  regCenter:
    ...
  jobs:
    ...
    jobErrorHandlerType: EMAIL 
    props:
      email:
        host: host
        port: 465
        username: username
        password: password
        useSsl: true
        subject: ElasticJob error message
        from: from@xxx.xx
        to: to1@xxx.xx,to2@xxx.xx
        cc: cc@xxx.xx
        bcc: bcc@xxx.xx
        debug: false

Wechat Enterprise Notification Strategy

Please refer to here for more details.

Maven POM:

<dependency>
    <groupId>org.apache.shardingsphere.elasticjob</groupId>
    <artifactId>elasticjob-error-handler-wechat</artifactId>
    <version>${latest.release.version}</version>
</dependency>

elasticjob:
  regCenter:
    ...
  jobs:
    ...
    jobErrorHandlerType: WECHAT 
    props:
      wechat:
        webhook: you_webhook
        connectTimeout: 3000
        readTimeout: 5000

Dingtalk Notification Strategy

Please refer to here for more details.

Maven POM:

<dependency>
    <groupId>org.apache.shardingsphere.elasticjob</groupId>
    <artifactId>elasticjob-error-handler-dingtalk</artifactId>
    <version>${latest.release.version}</version>
</dependency>

elasticjob:
  regCenter:
    ...
  jobs:
    ...
    jobErrorHandlerType: DINGTALK 
    props:
      dingtalk:
        webhook: you_webhook
        keyword: you_keyword
        secret: you_secret
        connectTimeout: 3000
        readTimeout: 5000