Spring使用之：Quartz定时任务为什么会被阻塞

Spring使用之：Quartz定时任务为什么会被阻塞

文章分类:Java编程 关键字: spring, quartz, 定时任务 问题：

周日，公司CTO给我打电话说，监控系统的数据从下午1点就不更新了。我登录服务器排除了数据同步问题，查看日志也没有例外抛出，查询了前一天的 日志发现几个数据库表空间溢出例外。最后定位，Spring定时任务挂掉了。重启应用恢复正常。周一早上，同样的问题又发生了，6点开始定时任务又停了。 Spring定时任务为什么会被阻塞呢？

原因：

周一中午，我在进行接口状态监控测试时发现，接口状态查询任务尽然会执行半小时。问题找到了，由于我在接口状态查询任务中没有设置读超时、在接口 网络繁忙时，接口状态查询任务会占用很长的时间，Spring定时任务默认都是并发执行的，不会等待上一次任务执行完毕，只要间隔时间到就会执行。接口状 态查询任务每5分钟执行一次，假如每次都执行1小时的话，其他任务就会被阻塞。因为Quartz的线程都被接口状态查询任务占用了。其他任务只有等待。

解决方法：

1.将JobDetail的concurrent属性配置为false。不允许任务并发执行。
2.任务执行时间较长时，查找根本问题。

实验：

JobOne.java

package  test.job;

import  java.util.Date;

public   class  JobOne {
    public   void  execute(){
        System.out.println("execute JobOne(" + new  Date()+ ")" );
        try  {
            Thread.sleep(1000000 );
        }catch (InterruptedException ire) {

        }
    }
}

package test.job;

import java.util.Date;

public class JobOne {
	public void execute(){
		System.out.println("execute JobOne("+new Date()+")");
		try {
			Thread.sleep(1000000);
		}catch(InterruptedException ire) {
			
		}
	}
}

JobTwo.java

package  test.job;

import  java.util.Date;

public   class  JobTwo {
    public   void  execute(){
        System.out.println("execute JobTwo(" + new  Date()+ ")" );
    }

}

package test.job;

import java.util.Date;

public class JobTwo {
	public void execute(){
		System.out.println("execute JobTwo("+new Date()+")");
	}

}

配置文件

<? xml   version = "1.0"   encoding = "UTF-8" ?>
< beans   xmlns = "http://www.springframework.org/schema/beans"   xmlns:xsi = "http://www.w3.org/2001/XMLSchema-instance"
       xmlns:aop = "http://www.springframework.org/schema/aop"   xmlns:tx = "http://www.springframework.org/schema/tx"
       xsi:schemaLocation ="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-

beans-2.0.xsd
            http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.0.xsd
            http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.0.xsd">

    <!--===== jobOne =====-->

    <!-- job -->

    < bean   id = "jobOne"   class = "test.job.JobOne"   >

    </ bean >

    <!-- job detail -->

    < bean   id = "jobOneDetail"   class = "org.springframework.scheduling.quartz.MethodInvokingJobDetailFactoryBean" >
        < property   name = "targetObject"   ref = "jobOne" />
        < property   name = "targetMethod"   value = "execute" />
        < property   name = "concurrent"   value = "true"   />
    </ bean >

    <!-- Trigger -->

    < bean   id = "jobOneSimpleTrigger"   class = "org.springframework.scheduling.quartz.SimpleTriggerBean" >
        < property   name = "jobDetail"   ref = "jobOneDetail"   />
        < property   name = "startDelay" > < value > 0 </ value > </ property >
        < property   name = "repeatInterval" > < value > 1000 </ value > </ property >
    </ bean >

    <!--===== jobTwo =====-->

    <!-- job -->

    < bean   id = "jobTwo"   class = "test.job.JobTwo"   >

    </ bean >

    <!-- job detail -->

    < bean   id = "jobTwoDetail"   class = "org.springframework.scheduling.quartz.MethodInvokingJobDetailFactoryBean" >
        < property   name = "targetObject"   ref = "jobTwo" />
        < property   name = "targetMethod"   value = "execute" />
        < property   name = "concurrent"   value = "true"   />
    </ bean >

    <!-- Trigger -->

    < bean   id = "jobTwoSimpleTrigger"   class = "org.springframework.scheduling.quartz.SimpleTriggerBean" >
        < property   name = "jobDetail"   ref = "jobTwoDetail"   />
        < property   name = "startDelay" > < value > 0 </ value > </ property >
        < property   name = "repeatInterval" > < value > 1000 </ value > </ property >
    </ bean >


    <!--===== Schedule =====-->

    <!-- schedule -->

    < bean    class = "org.springframework.scheduling.quartz.SchedulerFactoryBean" >
        < property   name = "triggers" >
            < list >
                < ref   local = "jobOneSimpleTrigger" />
                < ref   local = "jobTwoSimpleTrigger" />
            </ list >
        </ property >
    </ bean >

</ beans >

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-

beans-2.0.xsd
            http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.0.xsd
            http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.0.xsd">

    <!--===== jobOne =====-->
    
    <!-- job -->
    
    <bean id="jobOne" class="test.job.JobOne" >
        
    </bean>
    
    <!-- job detail -->
    
    <bean id="jobOneDetail" class="org.springframework.scheduling.quartz.MethodInvokingJobDetailFactoryBean">
        <property name="targetObject" ref="jobOne"/>
        <property name="targetMethod" value="execute"/>
        <property name="concurrent" value="true" />
    </bean>
    
    <!-- Trigger -->
    
    <bean id="jobOneSimpleTrigger" class="org.springframework.scheduling.quartz.SimpleTriggerBean">
        <property name="jobDetail" ref="jobOneDetail" />
        <property name="startDelay"><value>0</value></property>
        <property name="repeatInterval"><value>1000</value></property>
    </bean>
    
    <!--===== jobTwo =====-->
    
    <!-- job -->
    
    <bean id="jobTwo" class="test.job.JobTwo" >
        
    </bean>
    
    <!-- job detail -->
    
    <bean id="jobTwoDetail" class="org.springframework.scheduling.quartz.MethodInvokingJobDetailFactoryBean">
        <property name="targetObject" ref="jobTwo"/>
        <property name="targetMethod" value="execute"/>
        <property name="concurrent" value="true" />
    </bean>
    
    <!-- Trigger -->
    
    <bean id="jobTwoSimpleTrigger" class="org.springframework.scheduling.quartz.SimpleTriggerBean">
        <property name="jobDetail" ref="jobTwoDetail" />
        <property name="startDelay"><value>0</value></property>
        <property name="repeatInterval"><value>1000</value></property>
    </bean>
    
    
    <!--===== Schedule =====-->
   
    <!-- schedule -->
    
    <bean  class="org.springframework.scheduling.quartz.SchedulerFactoryBean">
        <property name="triggers">
            <list>
                <ref local="jobOneSimpleTrigger"/>
                <ref local="jobTwoSimpleTrigger"/>
            </list>
        </property>
    </bean>
    
</beans>

MAIN类：

package  test.job;

import  org.springframework.context.ApplicationContext;
import  org.springframework.context.support.ClassPathXmlApplicationContext;

public   class  JobTest {
    private   ApplicationContext ac;

    public  JobTest(ApplicationContext ac) {
        this .ac = ac;
    }
    /**
     * @param args
     */
    public   static   void  main(String[] args) {
        JobTest job = new  JobTest( new  ClassPathXmlApplicationContext( "applicationContext.xml" ));


    }

}

package test.job;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class JobTest {
	private  ApplicationContext ac;

	public JobTest(ApplicationContext ac) {
		this.ac = ac;
	}
	/**
	 * @param args
	 */
	public static void main(String[] args) {
		JobTest job = new JobTest(new ClassPathXmlApplicationContext("applicationContext.xml"));
		

	}

}

测试结果：

当jobOne的concurrent为true时：

execute JobOne(Thu Jan 24 13:40:22 CST 2008)
execute JobTwo(Thu Jan 24 13:40:22 CST 2008)
execute JobOne(Thu Jan 24 13:40:22 CST 2008)
execute JobTwo(Thu Jan 24 13:40:22 CST 2008)
execute JobOne(Thu Jan 24 13:40:23 CST 2008)
execute JobTwo(Thu Jan 24 13:40:23 CST 2008)
execute JobOne(Thu Jan 24 13:40:24 CST 2008)
execute JobTwo(Thu Jan 24 13:40:24 CST 2008)
execute JobOne(Thu Jan 24 13:40:25 CST 2008)
execute JobTwo(Thu Jan 24 13:40:25 CST 2008)
execute JobOne(Thu Jan 24 13:40:26 CST 2008)
execute JobTwo(Thu Jan 24 13:40:26 CST 2008)
execute JobOne(Thu Jan 24 13:40:27 CST 2008)
execute JobTwo(Thu Jan 24 13:40:27 CST 2008)
execute JobOne(Thu Jan 24 13:40:28 CST 2008)
execute JobTwo(Thu Jan 24 13:40:28 CST 2008)
execute JobOne(Thu Jan 24 13:40:29 CST 2008)
execute JobTwo(Thu Jan 24 13:40:29 CST 2008)
execute JobOne(Thu Jan 24 13:40:31 CST 2008)

（JobOne并发执行，到这里所有任务阻塞没有信息输出，可以看出默认有10个线程，都被JobOne占用）

当jobOne的concurrent为false时：

execute JobOne(Thu Jan 24 13:43:00 CST 2008)
execute JobTwo(Thu Jan 24 13:43:00 CST 2008)
execute JobTwo(Thu Jan 24 13:43:00 CST 2008)
execute JobTwo(Thu Jan 24 13:43:01 CST 2008)
execute JobTwo(Thu Jan 24 13:43:02 CST 2008)
execute JobTwo(Thu Jan 24 13:43:03 CST 2008)
execute JobTwo(Thu Jan 24 13:43:04 CST 2008)
execute JobTwo(Thu Jan 24 13:43:05 CST 2008)
execute JobTwo(Thu Jan 24 13:43:06 CST 2008)
execute JobTwo(Thu Jan 24 13:43:07 CST 2008)
execute JobTwo(Thu Jan 24 13:43:08 CST 2008)
execute JobTwo(Thu Jan 24 13:43:09 CST 2008)

（JobOne不并发执行，JobTwo不会被阻塞）