tomcat执行 shutdown.sh, 服务是关闭了，但是ps -ef仍然能看到相关进程，
导致进程不断增多（不要和我说kill -9 ）, 查看tomcat 的 catalina.out 日志，
发现如下日志
26-Jun-2019 19:43:45.248 WARNING [localhost-startStop-2] org.apache.catalina.loader.WebappClassLoaderBase.clearReferencesJdbc The web application [transaction_agent] registered the JDBC driver [com.alibaba.druid.proxy.DruidDriver] but failed to unregister it when the web application was stopped. To prevent a memory leak, the JDBC Driver has been forcibly unregistered.
26-Jun-2019 19:43:45.248 WARNING [localhost-startStop-2] org.apache.catalina.loader.WebappClassLoaderBase.clearReferencesJdbc The web application [transaction_agent] registered the JDBC driver [com.mysql.jdbc.Driver] but failed to unregister it when the web application was stopped. To prevent a memory leak, the JDBC Driver has been forcibly unregistered.
26-Jun-2019 19:43:45.249 WARNING [localhost-startStop-2] org.apache.catalina.loader.WebappClassLoaderBase.clearReferencesThreads The web application [transaction_agent] appears to have started a thread named [Abandoned connection cleanup thread] but has failed to stop it. This is very likely to create a memory leak. Stack trace of thread:
java.lang.Object.wait(Native Method)
java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:143)
com.mysql.jdbc.AbandonedConnectionCleanupThread.run(AbandonedConnectionCleanupThread.java:41)
26-Jun-2019 19:43:45.250 WARNING [localhost-startStop-2] org.apache.catalina.loader.WebappClassLoaderBase.clearReferencesThreads The web application [transaction_agent] appears to have started a thread named [pool-1-thread-1] but has failed to stop it. This is very likely to create a memory leak. Stack trace of thread:
sun.misc.Unsafe.park(Native Method)
java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)
java.util.concurrent.SynchronousQueue$TransferStack.awaitFulfill(SynchronousQueue.java:458)
java.util.concurrent.SynchronousQueue$TransferStack.transfer(SynchronousQueue.java:362)
java.util.concurrent.SynchronousQueue.take(SynchronousQueue.java:924)
java.util.concurrent.ThreadPoolExecutor.getTask(ThreadPoolExecutor.java:1067)
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1127)
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
java.lang.Thread.run(Thread.java:745)
26-Jun-2019 19:43:45.251 WARNING [localhost-startStop-2] org.apache.catalina.loader.WebappClassLoaderBase.clearReferencesThreads The web application [transaction_agent] appears to have started a thread named [pool-7-thread-1] but has failed to stop it. This is very likely to create a memory leak. Stack trace of thread:
sun.misc.Unsafe.park(Native Method)
java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)
java.util.concurrent.SynchronousQueue$TransferStack.awaitFulfill(SynchronousQueue.java:458)
java.util.concurrent.SynchronousQueue$TransferStack.transfer(SynchronousQueue.java:362)
java.util.concurrent.SynchronousQueue.take(SynchronousQueue.java:924)
java.util.concurrent.ThreadPoolExecutor.getTask(ThreadPoolExecutor.java:1067)
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1127)
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
java.lang.Thread.run(Thread.java:745)
26-Jun-2019 19:43:45.252 WARNING [localhost-startStop-2] org.apache.catalina.loader.WebappClassLoaderBase.clearReferencesThreads The web application [transaction_agent] appears to have started a thread named [pool-1-thread-2] but has failed to stop it. This is very likely to create a memory leak. Stack trace of thread:
sun.misc.Unsafe.park(Native Method)
java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)
java.util.concurrent.SynchronousQueue$TransferStack.awaitFulfill(SynchronousQueue.java:458)
java.util.concurrent.SynchronousQueue$TransferStack.transfer(SynchronousQueue.java:362)
java.util.concurrent.SynchronousQueue.take(SynchronousQueue.java:924)
java.util.concurrent.ThreadPoolExecutor.getTask(ThreadPoolExecutor.java:1067)
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1127)
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
java.lang.Thread.run(Thread.java:745)
26-Jun-2019 19:43:45.253 WARNING [localhost-startStop-2] org.apache.catalina.loader.WebappClassLoaderBase.clearReferencesThreads The web application [transaction_agent] appears to have started a thread named [pool-7-thread-2] but has failed to stop it. This is very likely to create a memory leak. Stack trace of thread:
sun.misc.Unsafe.park(Native Method)
java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)
java.util.concurrent.SynchronousQueue$TransferStack.awaitFulfill(SynchronousQueue.java:458)
java.util.concurrent.SynchronousQueue$TransferStack.transfer(SynchronousQueue.java:362)
java.util.concurrent.SynchronousQueue.take(SynchronousQueue.java:924)
java.util.concurrent.ThreadPoolExecutor.getTask(ThreadPoolExecutor.java:1067)
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1127)
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
java.lang.Thread.run(Thread.java:745)
可以看到有两个警告，第一个是数据库连接无法释放，第二个看着是线程池的
问题。我尝试将线程池相关代码注册掉。 发布，然后shutdown.sh ，发现进程
可以正常关闭。所以初步判定是线程池的这个问题导致的进程无法停止。
线程池伪代码如下
public class AA {
ThreadPoolExecutor executor = (ThreadPoolExecutor)Executors.newCachedThreadPool();
private String handleDyPosp(String s) throws Exception {
DCallable dCallable = new DCallable(s);
FutureTask<String> futureTask = new FutureTask(dCallable);
executor.executor(futureTask);
String s = futureTask.get(50,TimeUnit.SECONDS);
}
求解决方案
