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

Java代码

1. package test.job;  
2.   
3. import java.util.Date;  
4.   
5. public class JobOne {  
6.     public void execute(){  
7.         System.out.println("execute JobOne("+new Date()+")");  
8.         try {  
9.             Thread.sleep(1000000);  
10.         }catch(InterruptedException ire) {  
11.               
12.         }  
13.     }  
14. }  

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

Java代码

1. package test.job;  
2.   
3. import java.util.Date;  
4.   
5. public class JobTwo {  
6.     public void execute(){  
7.         System.out.println("execute JobTwo("+new Date()+")");  
8.     }  
9.   
10. }  

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代码

1. <?xml version="1.0" encoding="UTF-8"?>  
2. <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"  
3.        xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"  
4.        xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-  
5.   
6. beans-2.0.xsd  
7.             http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.0.xsd  
8.             http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.0.xsd">  
9.   
10.     <!--===== jobOne =====-->  
11.       
12.     <!-- job -->  
13.       
14.     <bean id="jobOne" class="test.job.JobOne" >  
15.           
16.     </bean>  
17.       
18.     <!-- job detail -->  
19.       
20.     <bean id="jobOneDetail" class="org.springframework.scheduling.quartz.MethodInvokingJobDetailFactoryBean">  
21.         <property name="targetObject" ref="jobOne"/>  
22.         <property name="targetMethod" value="execute"/>  
23.         <property name="concurrent" value="true" />  
24.     </bean>  
25.       
26.     <!-- Trigger -->  
27.       
28.     <bean id="jobOneSimpleTrigger" class="org.springframework.scheduling.quartz.SimpleTriggerBean">  
29.         <property name="jobDetail" ref="jobOneDetail" />  
30.         <property name="startDelay"><value>0</value></property>  
31.         <property name="repeatInterval"><value>1000</value></property>  
32.     </bean>  
33.       
34.     <!--===== jobTwo =====-->  
35.       
36.     <!-- job -->  
37.       
38.     <bean id="jobTwo" class="test.job.JobTwo" >  
39.           
40.     </bean>  
41.       
42.     <!-- job detail -->  
43.       
44.     <bean id="jobTwoDetail" class="org.springframework.scheduling.quartz.MethodInvokingJobDetailFactoryBean">  
45.         <property name="targetObject" ref="jobTwo"/>  
46.         <property name="targetMethod" value="execute"/>  
47.         <property name="concurrent" value="true" />  
48.     </bean>  
49.       
50.     <!-- Trigger -->  
51.       
52.     <bean id="jobTwoSimpleTrigger" class="org.springframework.scheduling.quartz.SimpleTriggerBean">  
53.         <property name="jobDetail" ref="jobTwoDetail" />  
54.         <property name="startDelay"><value>0</value></property>  
55.         <property name="repeatInterval"><value>1000</value></property>  
56.     </bean>  
57.       
58.       
59.     <!--===== Schedule =====-->  
60.      
61.     <!-- schedule -->  
62.       
63.     <bean  class="org.springframework.scheduling.quartz.SchedulerFactoryBean">  
64.         <property name="triggers">  
65.             <list>  
66.                 <ref local="jobOneSimpleTrigger"/>  
67.                 <ref local="jobTwoSimpleTrigger"/>  
68.             </list>  
69.         </property>  
70.     </bean>  
71.       
72. </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：

Java代码

1. package test.job;  
2.   
3. import org.springframework.context.ApplicationContext;  
4. import org.springframework.context.support.ClassPathXmlApplicationContext;  
5.   
6. public class JobTest {  
7.     private  ApplicationContext ac;  
8.   
9.     public JobTest(ApplicationContext ac) {  
10.         this.ac = ac;  
11.     }  
12.     /** 
13.      * @param args 
14.      */  
15.     public static void main(String[] args) {  
16.         JobTest job = new JobTest(new ClassPathXmlApplicationContext("applicationContext.xml"));  
17.           
18.   
19.     }  
20.   
21. }  

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）