玩战部署防止Tomcat停止

Question

我目前在 Tomcat 下使用我的 play 应用程序时遇到了一些 onStop 问题。 我正在使用 play 2.2.2、sbt 0.13.0、scala 2.10.4 和 Tomcat 7 和 jdk1.6。

要创建一个战争文件，我使用 play2war 插件（1.2）：

Play2WarKeys.servletVersion := "2.5"

所以部署和运行应用程序以及 Tomcat 本身运行没有任何问题。但是，一旦我尝试使用默认的 shutdown.sh 停止服务器，我就会得到 ​​p>

SEVERE: The web application [/WEBSERVICE] appears to have started a thread named [play-scheduler-1] but has failed to stop it. This is very likely to create a memory leak.
Aug 21, 2014 6:15:18 PM org.apache.catalina.loader.WebappClassLoader clearReferencesThreads
SEVERE: The web application [/WEBSERVICE] appears to have started a thread named [play-akka.actor.default-dispatcher-3] but has failed to stop it. This is very likely to create a memory leak.
Aug 21, 2014 6:15:18 PM org.apache.catalina.loader.WebappClassLoader clearReferencesThreads
SEVERE: The web application [/WEBSERVICE] appears to have started a thread named [play-akka.actor.default-dispatcher-4] but has failed to stop it. This is very likely to create a memory leak.
Aug 21, 2014 6:15:18 PM org.apache.catalina.loader.WebappClassLoader clearReferencesThreads
SEVERE: The web application [/WEBSERVICE] appears to have started a thread named [play-akka.actor.default-dispatcher-5] but has failed to stop it. This is very likely to create a memory leak.
Aug 21, 2014 6:15:18 PM org.apache.catalina.loader.WebappClassLoader checkThreadLocalMapForLeaks
SEVERE: The web application [/WEBSERVICE] created a ThreadLocal with key of type [java.lang.ThreadLocal] (value [java.lang.ThreadLocal@384e9bea]) and a value of type [scala.concurrent.forkjoin.ForkJoinPool.Submitter] (value [scala.concurrent.forkjoin.ForkJoinPool$Submitter@4e57dc21]) but failed to remove it when the web application was stopped. Threads are going to be renewed over time to try and avoid a probable memory leak.
Aug 21, 2014 6:15:18 PM org.apache.catalina.loader.WebappClassLoader checkThreadLocalMapForLeaks
SEVERE: The web application [/WEBSERVICE] created a ThreadLocal with key of type [scala.concurrent.forkjoin.ThreadLocalRandom$1] (value [scala.concurrent.forkjoin.ThreadLocalRandom$1@4679cf8c]) and a value of type [scala.concurrent.forkjoin.ThreadLocalRandom] (value [scala.concurrent.forkjoin.ThreadLocalRandom@67291479]) but failed to remove it when the web application was stopped. Threads are going to be renewed over time to try and avoid a probable memory leak.
Aug 21, 2014 6:15:18 PM org.apache.catalina.loader.WebappClassLoader checkThreadLocalMapForLeaks
SEVERE: The web application [/WEBSERVICE] created a ThreadLocal with key of type [java.lang.ThreadLocal] (value [java.lang.ThreadLocal@384e9bea]) and a value of type [scala.concurrent.forkjoin.ForkJoinPool.Submitter] (value [scala.concurrent.forkjoin.ForkJoinPool$Submitter@39ff48d8]) but failed to remove it when the web application was stopped. Threads are going to be renewed over time to try and avoid a probable memory leak.
Aug 21, 2014 6:15:18 PM org.apache.catalina.loader.WebappClassLoader checkThreadLocalMapForLeaks
SEVERE: The web application [/WEBSERVICE] created a ThreadLocal with key of type [java.lang.ThreadLocal] (value [java.lang.ThreadLocal@384e9bea]) and a value of type [scala.concurrent.forkjoin.ForkJoinPool.Submitter] (value [scala.concurrent.forkjoin.ForkJoinPool$Submitter@27077aa7]) but failed to remove it when the web application was stopped. Threads are going to be renewed over time to try and avoid a probable memory leak.
Aug 21, 2014 6:15:18 PM org.apache.catalina.loader.WebappClassLoader checkThreadLocalMapForLeaks
SEVERE: The web application [/WEBSERVICE] created a ThreadLocal with key of type [akka.actor.ActorCell$$anon$1] (value [akka.actor.ActorCell$$anon$1@5c057df5]) and a value of type [scala.collection.immutable.Nil$] (value [List()]) but failed to remove it when the web application was stopped. Threads are going to be renewed over time to try and avoid a probable memory leak.
Aug 21, 2014 6:15:18 PM org.apache.catalina.loader.WebappClassLoader checkThreadLocalMapForLeaks
SEVERE: The web application [/WEBSERVICE] created a ThreadLocal with key of type [java.lang.ThreadLocal] (value [java.lang.ThreadLocal@384e9bea]) and a value of type [scala.concurrent.forkjoin.ForkJoinPool.Submitter] (value [scala.concurrent.forkjoin.ForkJoinPool$Submitter@6c908f05]) but failed to remove it when the web application was stopped. Threads are going to be renewed over time to try and avoid a probable memory leak.
Aug 21, 2014 6:15:18 PM org.apache.catalina.loader.WebappClassLoader checkThreadLocalMapForLeaks
SEVERE: The web application [/WEBSERVICE] created a ThreadLocal with key of type [scala.concurrent.forkjoin.ThreadLocalRandom$1] (value [scala.concurrent.forkjoin.ThreadLocalRandom$1@4679cf8c]) and a value of type [scala.concurrent.forkjoin.ThreadLocalRandom] (value [scala.concurrent.forkjoin.ThreadLocalRandom@69dc8f2]) but failed to remove it when the web application was stopped. Threads are going to be renewed over time to try and avoid a probable memory leak.

之后应用程序和tomcat都关闭了，但我仍然看到tomcat prozess僵尸通过

ps -ef

完全杀死它的唯一可能是kill -9 <pid>。 所以我开始在网上搜索，偶然发现了类似的问题，建议在使用的演员系统上执行.shutdown() 和awaitTermination()。

所以我创建了一个覆盖 onStop 方法的全局对象：

object Global extends GlobalSettings {
 val actorSystem = Application.system

 override def onStop(app: Application) {
    implicit val timeout = Timeout(4 seconds)

    Logger.info("Shutting down Actorsystem")

    Akka.system.shutdown()
    Akka.system.awaitTermination(timeout.duration)
    actorSystem.shutdown()
    actorSystem.awaitTermination(timeout.duration)
  }

}

但这并不能解决问题。我尝试通过Akka.system 关闭我自己的 ActorSystem 以及默认的播放 actorsystem，但它没有任何效果。
当我在 catalina.out 中看到 Log 语句时，onStop 方法得到执行。

所以为了解决这个问题，我只用一个简单的字符串响应设置了一个全新的播放 2.3.3。除了播放默认的演员系统外，没有演员系统，并集成了 play2war 插件，以查看问题是由我的代码还是由 play 本身引起的。问题是一样的。

所以我正在锁定一些建议，如何关闭这些调度程序和调度程序等等，这些调度程序和调度程序等是由游戏产生但在关闭时不会被杀死的？

我真的很感激任何帮助！

编辑：

我还尝试了Oracle driver memory leak - Tomcat 中提供的解决方案，方法是删除我的应用程序库中的 oracle 驱动程序 - 但 tomcat 行为没有任何变化

Play2war Github 中也有多个基于此主题的主题，但遗憾的是没有解决方案：

Leak error and Tomcat is never shutdown #108

tomcat 6: hangs on shutdown #161

Answer 1

所以我在这个帖子中找到了解决这个问题的方法： is-there-any-light-weight-actors-in-akka

如Roland Kuhn 所述，可以通过akka 将线程设置为守护进程，最终不会阻止VM 关闭。

要做到这一点，只需在 application.conf 中设置：

play.akka.daemonic=on

或者哪个也可以工作：

akka {
  daemonic=on
}

这样，tomcat 将毫无问题地关闭。