cpu使用率100%问题

案例1：测试环境一个springboot服务部署在阿里云serverless，后台监控显示cpu占比100%，日志里未发现代码报错，此时该服务提供的接口均不能访问

//top -H -p pid 查看线程信息：cpu占有率高的两个线程
  PID USER      PR  NI    VIRT    RES    SHR S %CPU %MEM     TIME+ COMMAND     
   21 root      20   0 3085284 544152  20840 R 49.5 13.5  27:13.11 Wisp-Root-W+
   22 root      20   0 3085284 544152  20840 R 49.5 13.5  27:13.42 Wisp-Root-W+

//jstack pid|grep -A 10 spid 查看堆栈信息
 - Coroutine [0x7f4bb4051e80] "Pinpoint-SocketFactory-Timer(13-0)" #15 active=200 steal=0 steal_fail=0 preempt=0 park=1/-1 containerId=0 cg=0/0 ttr=0
        at java.dyn.CoroutineSupport.unsafeSymmetricYieldTo(CoroutineSupport.java:140)
        at com.alibaba.wisp.engine.WispTask.switchTo(WispTask.java:325)
        at com.alibaba.wisp.engine.WispCarrier.yieldTo(WispCarrier.java:435)
        at com.alibaba.wisp.engine.WispCarrier.schedule(WispCarrier.java:273)
        at com.alibaba.wisp.engine.WispTask.parkInternal(WispTask.java:417)
        at com.alibaba.wisp.engine.WispTask.jdkPark(WispTask.java:469)
        at com.alibaba.wisp.engine.WispTask.sleep(WispTask.java:353)
        at com.alibaba.wisp.engine.WispEngine$5.sleep(WispEngine.java:246)
        at java.lang.Thread.sleep(Thread.java:384)
        at org.jboss.netty.util.HashedWheelTimer$Worker.waitForNextTick(HashedWheelTimer.java:445)
--
        at java.lang.ref.Reference$ReferenceHandler.run(Reference.java:153)


 - Coroutine [0x7f4bc0007ef0] "Timer-0" #9 active=5 steal=0 steal_fail=0 preempt=0 park=-1/0 containerId=0 cg=0/0 ttr=0
        at java.dyn.CoroutineSupport.unsafeSymmetricYieldTo(CoroutineSupport.java:140)
        at com.alibaba.wisp.engine.WispTask.switchTo(WispTask.java:325)
        at com.alibaba.wisp.engine.WispCarrier.yieldTo(WispCarrier.java:435)
        at com.alibaba.wisp.engine.WispCarrier.schedule(WispCarrier.java:273)
        at com.alibaba.wisp.engine.WispTask.parkInternal(WispTask.java:417)
        at com.alibaba.wisp.engine.WispTask.park(WispTask.java:480)
        at java.lang.Object.wait(Native Method)
        at java.util.TimerThread.mainLoop(Timer.java:552)
        - waiting to lock <0x00000000e037e3b8> (a java.util.TaskQueue)
        at java.util.TimerThread.run(Timer.java:505)
        at com.alibaba.wisp.engine.WispTask.runOutsideWisp(WispTask.java:295)
        at com.alibaba.wisp.engine.WispTask.runCommand(WispTask.java:270)
        at com.alibaba.wisp.engine.WispTask.access$100(WispTask.java:53)
        at com.alibaba.wisp.engine.WispTask$CacheableCoroutine.run(WispTask.java:241)
        at java.dyn.CoroutineBase.startInternal(CoroutineBase.java:62)

//java -version 查看jdk版本
openjdk version "1.8.0_302"
OpenJDK Runtime Environment (Alibaba Dragonwell 8.8.8-b01) (build 1.8.0_302-b1)
OpenJDK 64-Bit Server VM (Alibaba Dragonwell 8.8.8-b01) (build 25.302-b1, mixed mode)

解决办法：测试环境使用了 OpenJDK Dragonwell版本，线程信息和堆栈信息均有wisp提示，可能和jdk版本有关系，切换到 OpenJDK 版本后，cpu使用率下来了，服务正常。具体 Dragonwell 版本哪里引起的问题，不知道了，待以后查看