jstack 有大量的TIME_WAITING（2392个）,具体如下：
"http-nio-8000-exec-78" daemon prio=10 tid=0x00007f476c04b000 nid=0x1c3f1 waiting on condition [0x00007f40f9bec000]
java.lang.Thread.State: TIMED_WAITING (parking)
at sun.misc.Unsafe.park(Native Method)
- parking to wait for <0x00000006e1af7b98> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject)
at java.util.concurrent.locks.LockSupport.parkNanos(LockSupport.java:226)
at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.awaitNanos(AbstractQueuedSynchronizer.java:2082)
at java.util.concurrent.LinkedBlockingQueue.poll(LinkedBlockingQueue.java:467)
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(ThreadPoolExecutor.java:1068)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1130)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:745)
jstat
S0 S1 E O P YGC YGCT FGC FGCT GCT
0.00 0.00 3.15 29.43 24.38 8908 769.056 386 512.414 1281.470
0.00 0.00 57.92 29.43 24.38 8908 769.056 386 512.414 1281.470
0.00 0.00 76.54 29.43 24.38 8908 769.056 386 512.414 1281.470
26.44 0.00 4.80 29.43 24.38 8909 769.138 386 512.414 1281.552
26.44 0.00 5.52 29.43 24.38 8909 769.138 386 512.414 1281.552
26.44 0.00 6.09 29.43 24.38 8909 769.138 386 512.414 1281.552
26.44 0.00 7.69 29.43 24.38 8909 769.138 386 512.414 1281.552
26.44 0.00 10.05 29.43 24.38 8909 769.138 386 512.414 1281.552
26.44 0.00 11.42 29.43 24.38 8909 769.138 386 512.414 1281.552
26.44 0.00 30.78 29.43 24.38 8909 769.138 386 512.414 1281.552
