ElasticJob‐Lite：事件追踪

添加依赖（​​3.0.1​​​是目前最新的​​Releases​​版本）：

<dependency>
            <groupId>org.apache.shardingsphere.elasticjob</groupId>
            <artifactId>elasticjob-lite-core</artifactId>
            <version>3.0.1</version>
        </dependency>

​​ElasticJob​​​提供了事件追踪功能，可通过事件订阅的方式处理调度过程的重要事件，用于查询、统计和监控。目前提供了基于关系型数据库的事件订阅方式记录事件，开发者也可以通过​​SPI​​​自行扩展，博主在下面这篇博客中介绍了如何通过​​SPI​​自行扩展作业类型，方式是类似的。

• ​​ElasticJob‐Lite：扩展作业类型​​

​​pom.xml​​：

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.kaven</groupId>
    <artifactId>job</artifactId>
    <version>1.0-SNAPSHOT</version>
    
    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
    </properties>
    
    <dependencies>
        <dependency>
            <groupId>org.apache.shardingsphere.elasticjob</groupId>
            <artifactId>elasticjob-lite-core</artifactId>
            <version>3.0.0</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.26</version>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.22</version>
            <scope>provided</scope>
        </dependency>
    </dependencies>
</project>

作业定义（以​​Simple​​作业为例）：

package com.kaven.job;

import lombok.SneakyThrows;
import org.apache.shardingsphere.elasticjob.api.ShardingContext;
import org.apache.shardingsphere.elasticjob.simple.job.SimpleJob;

import java.text.SimpleDateFormat;
import java.util.Date;

/**
 * @Author: ITKaven
 * @Date: 2021/11/20 17:02
 * @Leetcode: https://leetcode-cn.com/u/kavenit
 * @Notes:
 */
public class MySimpleJob implements SimpleJob {
    private static final SimpleDateFormat formatter =new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");

    @SneakyThrows
    @Override
    public void execute(ShardingContext shardingContext) {
        switch (shardingContext.getShardingItem()) {
            case 0:
                System.out.println(formatter.format(new Date()) + " : ShardingItem[0]");
                Thread.sleep(2000);
                break;
            case 1:
                System.out.println(formatter.format(new Date()) + " : ShardingItem[1]");
                Thread.sleep(2000);
                break;
            case 2:
                System.out.println(formatter.format(new Date()) + " : ShardingItem[2]");
                Thread.sleep(2000);
                break;
            default:
                System.out.println(formatter.format(new Date()) + " : Unknown ShardingItem");
        }
    }
}

启动类​​Application​​ ：

package com.kaven.job;

import com.mysql.cj.jdbc.MysqlDataSource;
import org.apache.shardingsphere.elasticjob.api.JobConfiguration;
import org.apache.shardingsphere.elasticjob.lite.api.bootstrap.impl.ScheduleJobBootstrap;
import org.apache.shardingsphere.elasticjob.reg.base.CoordinatorRegistryCenter;
import org.apache.shardingsphere.elasticjob.reg.zookeeper.ZookeeperConfiguration;
import org.apache.shardingsphere.elasticjob.reg.zookeeper.ZookeeperRegistryCenter;
import org.apache.shardingsphere.elasticjob.tracing.api.TracingConfiguration;

import javax.sql.DataSource;

/**
 * @Author: ITKaven
 * @Date: 2021/11/20 17:05
 * @Leetcode: https://leetcode-cn.com/u/kavenit
 * @Notes:
 */
public class Application {

    public static void main(String[] args) {
        new ScheduleJobBootstrap(createRegistryCenter(), new MySimpleJob(),
                createJobConfiguration()).schedule();
    }
    
    // 注册中心
    private static CoordinatorRegistryCenter createRegistryCenter() {
        ZookeeperConfiguration zc = new ZookeeperConfiguration("192.168.31.172:9000", "my-job");
        zc.setConnectionTimeoutMilliseconds(40000);
        zc.setMaxRetries(5);
        CoordinatorRegistryCenter regCenter = new ZookeeperRegistryCenter(zc);
        regCenter.init();
        return regCenter;
    }

    // 数据源
    private static DataSource getDataSource() {
        MysqlDataSource dataSource = new MysqlDataSource();
        dataSource.setUser("root");
        dataSource.setPassword("[e-mail]");
        dataSource.setURL("jdbc:mysql://localhost:3306/trace?useUnicode=true&characterEncoding=UTF-8&useSSL=false&serverTimezone=Asia/Shanghai&allowPublicKeyRetrieval=true");
        return dataSource;
    }

    // 作业配置
    private static JobConfiguration createJobConfiguration() {
        TracingConfiguration tracingConfig = new TracingConfiguration<>("RDB", getDataSource());
        return JobConfiguration.newBuilder("MySimpleJob", 3)
                .description("该作业有三个分片，每隔一分钟执行一次")
                .cron("30 * * * * ?")
                .addExtraConfigurations(tracingConfig)
                .overwrite(true)
                .failover(true)
                .build();
    }
}

执行作业后，数据库就会有作业的执行记录。

​​ElasticJob‐Lite​​的事件追踪就介绍到这里，如果博主有说错的地方或者大家有不同的见解，欢迎大家评论补充。