提供者dubbo线程池满，每天都会打印几个Dubbo_Jstack日志，但是消费方，提示是重试成功。下面的是dubbo的jstack日志分析。

等待的线程日志基本上都是
DubboServerHandler-172.16.189.81:20880-thread-198
threadId:337 - state:WAITING
stackTrace:
at sun.misc.Unsafe.park(Native Method)

• waiting on java.util.concurrent.SynchronousQueue$TransferStack@7749fb4a
  at java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)
  at java.util.concurrent.SynchronousQueue$TransferStack.awaitFulfill(SynchronousQueue.java:458)
  at java.util.concurrent.SynchronousQueue$TransferStack.transfer(SynchronousQueue.java:362)
  at java.util.concurrent.SynchronousQueue.take(SynchronousQueue.java:924)
  at java.util.concurrent.ThreadPoolExecutor.getTask(ThreadPoolExecutor.java:1067)
  at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1127)
  at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
  at java.lang.Thread.run(Thread.java:745)