title: Multiple TIMED_WAITING threads seen on tomcat 7 thread dump
body: <p>We keep monitoring our threads in tomcat 7 and off lately we started seeing that at times the number of threads would become double the normal value i.e. around 200 threads (rather than the usual around 80 threads). </p>
  
  <p>Upon taking a thread dump, I see that during the time the number of threads increase, the increase due to presence of a large number (around 100) of threads as shown below (all waiting on 588cc7d5):</p>
  
  <pre><code>"http-bio-8080-exec-201" - Thread t@2856
     java.lang.Thread.State: TIMED_WAITING
      at sun.misc.Unsafe.park(Native Method)
      - parking to wait for &lt;588cc7d5&gt; (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject)
      at java.util.concurrent.locks.LockSupport.parkNanos(Unknown Source)
      at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.awaitNanos(Unknown Source)
      at java.util.concurrent.LinkedBlockingQueue.poll(Unknown Source)
      at org.apache.tomcat.util.threads.TaskQueue.poll(TaskQueue.java:86)
      at org.apache.tomcat.util.threads.TaskQueue.poll(TaskQueue.java:32)
      at java.util.concurrent.ThreadPoolExecutor.getTask(Unknown Source)
      at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
      at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
      at java.lang.Thread.run(Unknown Source)
  
     Locked ownable synchronizers:
      - None
  </code></pre>
  
  <p>Does anyone know what can cause this behavior?</p>