org.apache.catalina.loader.WebappClassLoaderBase.checkStateForResourceLoading Illegal access

最近阿里云上的tomcat日志时不时的报错，虽然报错但是不影响正常业务。但是既然报错了肯定需要知道原因的。报错详情如下：

13-Oct-2015 08:26:56.061 INFO [service%0043ache.data] org.apache.catalina.loader.WebappClassLoaderBase.checkStateForResourceLoading Illegal access: this web application instance has been stopped already. Could not load [net.sf.ehcache.store.disk.Segment$1]. The following stack trace is thrown for debugging purposes as well as to attempt to terminate the thread which caused the illegal access.
 java.lang.IllegalStateException: Illegal access: this web application instance has been stopped already. Could not load [net.sf.ehcache.store.disk.Segment$1]. The following stack trace is thrown for debugging purposes as well as to attempt to terminate the thread which caused the illegal access.
    at org.apache.catalina.loader.WebappClassLoaderBase.checkStateForResourceLoading(WebappClassLoaderBase.java:1335)
    at org.apache.catalina.loader.WebappClassLoaderBase.checkStateForClassLoading(WebappClassLoaderBase.java:1321)
    at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1203)
    at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1164)
    at net.sf.ehcache.store.disk.Segment$HashIterator.(Segment.java:997)
    at net.sf.ehcache.store.disk.Segment.hashIterator(Segment.java:948)
    at net.sf.ehcache.store.disk.DiskStore$HashIterator.(DiskStore.java:999)
    at net.sf.ehcache.store.disk.DiskStore$KeyIterator.(DiskStore.java:1072)
    at net.sf.ehcache.store.disk.DiskStore$KeyIterator.(DiskStore.java:1072)
    at net.sf.ehcache.store.disk.DiskStore$KeySet.iterator(DiskStore.java:910)
    at net.sf.ehcache.store.disk.DiskStorageFactory$DiskExpiryTask.run(DiskStorageFactory.java:828)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
    at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
    at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
    at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)

我这产生问题的原因是：一个tomcat启动了两个进程。
解决办法：
1、查找出tomcat的进程，命令如下： ps -ef |grep tomcat
2、杀掉tomcat进程，命令如下： kill -9 tomcat的pid号
3、启动tomcat，恢复正常。 命令如下：sh startup.sh

为什么会产生两个进程呢？

在网上找了一大堆资料后，大致说法如下：
1、sh shutdown.sh 不能完全杀死tomcat或者是不能立马杀死tomcat
2、tomcat的con/server.xml中的context属性reloadable默认为true导致。

我觉得这个linux上启动两个tomcat进程和window的tomcat进程没杀死差不多。但是在windows上面，tomcat如果有一个进程在运行，再启动的时候就会报8080端口被占用。在Linux上却没有任何提示，这一点区别是不是可以说明在linux上可以手动进行类似的设置呢？
下图是我解决这个问题的命令截图：

CSDN的图片不能双击变大，有个折衷的办法是在图片上右键查看图片。