石英：内存泄漏？

Posted 2023-03-27

【中文标题】石英：内存泄漏？

【英文标题】：Quartz : Memory Leak?

【发布时间】：2011-09-28 16:13:21

【问题描述】：

我使用 Quartz 每小时运行一次作业。 servlet 在 Tomcat 上运行，我使用 ServletConextListener 来监听上下文何时被销毁。

当我关闭 tomcat 时，我收到消息：

“似乎已经启动了一个名为 [MyScheduler_Worker-1] 的线程，但未能停止它”。

但后来我看到这条消息：

“[DEBUG] 9 月 28 日上午 11:45:26.671 MyScheduler_Worker-1 [org.quartz.simpl.SimpleThreadPool]

WorkerThread 已关闭。”

那么假设这个线程没有内存泄漏是否安全？

这是我的日志的样子：

SEVERE: The web application [/*************] appears to have started a thread

named [MyScheduler_Worker-1] but has failed to stop it. This is very likely to c

reate a memory leak.

Sep 28, 2011 11:45:26 AM org.apache.catalina.loader.WebappClassLoader clearRefer

encesThreads

SEVERE: The web application [/*************] appears to have started a thread

named [MyScheduler_Worker-2] but has failed to stop it. This is very likely to c

reate a memory leak.

Sep 28, 2011 11:45:26 AM org.apache.catalina.loader.WebappClassLoader clearRefer

encesThreads

SEVERE: The web application [/*************] appears to have started a thread

named [MyScheduler_Worker-3] but has failed to stop it. This is very likely to c

reate a memory leak.

[DEBUG] 28 Sep 11:45:26.671 AM MyScheduler_Worker-2 [org.quartz.simpl.SimpleThre

adPool]

WorkerThread is shut down.



[DEBUG] 28 Sep 11:45:26.671 AM MyScheduler_Worker-1 [org.quartz.simpl.SimpleThre

adPool]

WorkerThread is shut down.



[DEBUG] 28 Sep 11:45:26.671 AM MyScheduler_Worker-3 [org.quartz.simpl.SimpleThre

adPool]

WorkerThread is shut down.

【问题讨论】：

据说Tomcat没有给Quartz足够的时间来关闭线程。但我还无法验证这一点。

【参考方案1】：

我知道这是一个旧线程，但以防其他人正在寻找它。

我们一直用于获取线程的警告，直到我们在 ServletContextListener.shutDown() 方法中添加关闭 Quartz 调度程序的代码。

关闭调度器：

            quartzScheduler.shutdown();

            int ct = 0;

            // Try waiting for the scheduler to shutdown. Only wait 30 seconds.
            while(ct < 30) 
                ct++;
                // Sleep for a second so the quartz worker threads die.  This 
                // suppresses a warning from Tomcat during shutdown.
                Thread.sleep(1000);
                if (quartzScheduler.isShutdown()) 
                    break;
                
            

【参考方案2】：

您可以假设没有内存泄漏，因为您看到了线程关闭消息。但是，可以通过在关闭前清除线程来克服警告。

The shutdown-hook plugin catches the event of the JVM terminating, and calls shutdown on the scheduler.

详情：- http://quartz-scheduler.org/documentation/quartz-2.x/configuration/ConfigPlugins