什么是任务调度
为什么需要分布式调度
Elastic-Job
环境搭建
更改Zookeeper配置
SpringBoot集成ElasticJob
什么是任务调度任务调度是为了自动完成特定任务,在约定的特定时刻去执行人物的过程
为什么需要分布式调度1.使用Spring定时器,在集群的情况下,可能会导致任务重复执行的情况,当我们部署了多台服务,同时每台服务又有定时任务时,若不进行合理的控制在同一时间,只有一个定时任务启动执行了,这时,定时执行的结果就可能存在混乱和错误了,考虑使用分布式锁,保证任务不会重复执行
2.大大提高了可用性,当做了集群之后,某个项目挂了,任务应该要由另外一个项目继续进行
3.单机处理始终有极限,假设该主服务器有ABCD四个任务,可以将任务分配给自己底下的从服务器,将它们调动起来一起来完成任务
Elastic-Jobzookeeper是一个注册中心,在Elastic-job过程中进行一个选举的功能,以及对节点的监听,谁被选举成leader谁才可以执行任务,一旦leader挂了,将会进行重新的选举,依赖zookeeper里面的信息
环境搭建第一步:Zookeeper安装并运行
1)解压zookeeper-3.4.11.tar.进入conf目录,复制zoo_sample.cfg文件,命名为zoo.cfg
2)进入bin目录,运行zkServer.cmd就可以了
3)解压ZooInspector运行文件
第二步:创建maven项目添加如下依赖
<dependency>
<groupId>com.dangdang</groupId>
<artifactId>elastic-job-lite-core</artifactId>
<version>2.1.5</version>
</dependency>
第三步:创建任务类
public class MyElasticJob implements SimpleJob {
public void execute(ShardingContext shardingContext){
System.out.println("执行任务"+new Date());
}
}
第四步:创建配置类
public class JobDemo {
public static void main(String[] args) {
//JobScheduler(注册中心对象,任务配置对象)
new JobScheduler(createRegistryCenter(),createJobConfiguration()).init();
}
//定时任务配置
private static LiteJobConfiguration createJobConfiguration() {
//定义作业核心配置newBuilder("任务名称","corn表达式","分片数量")
JobCoreConfiguration simpleCoreConfig = JobCoreConfiguration.newBuilder("myElasticJob","0/5 * * * * ?",1).build();
// 定义SIMPLE类型配置 cn.wolfcode.MyElasticJob
System.out.println("MyElasticJob.class.getCanonicalName---->"+ MyElasticJob.class.getCanonicalName());
SimpleJobConfiguration simpleJobConfig = new SimpleJobConfiguration(simpleCoreConfig,MyElasticJob.class.getCanonicalName());
//定义Lite作业根配置
LiteJobConfiguration simpleJobRootConfig = LiteJobConfiguration.newBuilder(simpleJobConfig).build();
return simpleJobRootConfig;
}
//注册中心配置
private static CoordinatorRegistryCenter createRegistryCenter() {
ZookeeperConfiguration zookeeperConfiguration = new ZookeeperConfiguration("43.143.161.59:2181", "elastic-job-demo");
//设置节点超时时间
zookeeperConfiguration.setSessionTimeoutMilliseconds(100);
//zookeeperConfiguration("zookeeper地址","项目名")
CoordinatorRegistryCenter regCenter = new ZookeeperRegistryCenter(zookeeperConfiguration);
regCenter.init();
return regCenter;
}
}
运行结果:
启动多台机器的时候,只有一台机器运行
当leader终止后,再次进行选取执行任务
更改Zookeeper配置虽然自己想每十秒执行一次,但运行结果
原因是zookeeper里面不允许覆盖里面配置的,要是想覆盖,就要
否则zookeeper还是读取里面的配置
SpringBoot集成ElasticJob第一步:添加Maven依赖
<?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>cn.wolfcode</groupId>
<artifactId>elstaic-job-boot</artifactId>
<version>1.0.0</version>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.1.3.RELEASE</version>
</parent>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>com.dangdang</groupId>
<artifactId>elastic-job-lite-spring</artifactId>
<version>2.1.5</version>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
</dependency>
</dependencies>
</project>
第二步:创建启动类
@SpringBootApplication
public class ElasticJobServer {
public static void main(String[] args) {
SpringApplication.run(ElasticJobServer.class,args);
}
}
第三步:创建任务类
@Component
public class MyElasticJob implements SimpleJob {
@Override
public void execute(ShardingContext shardingContext) {
System.out.println("定时调度:"+new Date());
}
}
第四步:创建任务配置类
@Configuration
public class JobConfig {
@Bean
public static CoordinatorRegistryCenter registryCenter(@Value("${zookeeper.url}") String url,@Value("${zookeeper.groupName}") String groupName) {
ZookeeperConfiguration zookeeperConfiguration = new ZookeeperConfiguration(url, groupName);
//设置节点超时时间
zookeeperConfiguration.setSessionTimeoutMilliseconds(100);
//zookeeperConfiguration("zookeeper地址","项目名")
CoordinatorRegistryCenter regCenter = new ZookeeperRegistryCenter(zookeeperConfiguration);
regCenter.init();
return regCenter;
}
//功能的方法
public static LiteJobConfiguration createJobConfiguration(Class clazz,String corn,int shardingCount) {
//定义作业核心配置newBuilder("任务名称","corn表达式","分片数量")
JobCoreConfiguration simpleCoreConfig = JobCoreConfiguration.newBuilder(clazz.getSimpleName(),corn,shardingCount).build();
// 定义SIMPLE类型配置 cn.wolfcode.MyElasticJob
System.out.println("MyElasticJob.class.getCanonicalName---->"+ MyElasticJob.class.getCanonicalName());
SimpleJobConfiguration simpleJobConfig = new SimpleJobConfiguration(simpleCoreConfig,clazz.getCanonicalName());
//定义Lite作业根配置
LiteJobConfiguration simpleJobRootConfig = LiteJobConfiguration.newBuilder(simpleJobConfig).build();
return simpleJobRootConfig;
}
@Bean(initMethod = "init")
public SpringJobScheduler testScheduler(MyElasticJob job,CoordinatorRegistryCenter registryCenter){
LiteJobConfiguration jobConfiguration = createJobConfiguration(job.getClass(),"0/5 * * * * ?",1);
return new SpringJobScheduler(job,registryCenter,jobConfiguration);
}
}
第五步:配置文件
zookeeper:
url: 43.143.161.59:2181
groupName: elastic-job-boot
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