jstack用法

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JSTACK查看输出 #

/opt/java8/bin/jstack -l 28367

2019-06-25 15:04:46

Full thread dump Java HotSpot(TM) 64-Bit Server VM (25.77-b03 mixed mode):


"Attach Listener" #453 daemon prio=9 os_prio=0 tid=0x00007f9f94001000 nid=0xf30 waiting on condition [0x0000000000000000]

   java.lang.Thread.State: RUNNABLE


   Locked ownable synchronizers:

        - None


"grpc-default-executor-263" #452 daemon prio=5 os_prio=0 tid=0x00007f9f4c01f800 nid=0x9aa waiting on condition [0x00007f9f398bd000]

   java.lang.Thread.State: TIMED_WAITING (parking)

        at sun.misc.Unsafe.park(Native Method)

        - parking to wait for  <0x00000007400243f0> (a java.util.concurrent.SynchronousQueue$TransferStack)

        at java.util.concurrent.locks.LockSupport.parkNanos(LockSupport.java:215)

        at java.util.concurrent.SynchronousQueue$TransferStack.awaitFulfill(SynchronousQueue.java:460)

        at java.util.concurrent.SynchronousQueue$TransferStack.transfer(SynchronousQueue.java:362)

        at java.util.concurrent.SynchronousQueue.poll(SynchronousQueue.java:941)

        at java.util.concurrent.ThreadPoolExecutor.getTask(ThreadPoolExecutor.java:1066)

        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)


   Locked ownable synchronizers:

        - None


"http-bio-8080-exec-10" #235 daemon prio=5 os_prio=0 tid=0x0000000001bcc800 nid=0x3c13 waiting on condition [0x00007f9f384a9000]

   java.lang.Thread.State: WAITING (parking)

        at sun.misc.Unsafe.park(Native Method)

        - parking to wait for  <0x0000000743d26638> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject)

        at java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)

        at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(AbstractQueuedSynchronizer.java:2039)

        at java.util.concurrent.LinkedBlockingQueue.take(LinkedBlockingQueue.java:442)

        at org.apache.tomcat.util.threads.TaskQueue.take(TaskQueue.java:104)

        at org.apache.tomcat.util.threads.TaskQueue.take(TaskQueue.java:32)

        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 org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)

        at java.lang.Thread.run(Thread.java:745)


   Locked ownable synchronizers:

        - None
jstack统计线程数 #

/opt/java8/bin/jstack -l 28367 | grep 'java.lang.Thread.State' | wc -l

jstack检测死锁 #
public class DeathLock {


    private static Lock lock1 = new ReentrantLock();

    private static Lock lock2 = new ReentrantLock();


    public static void deathLock() {

        Thread t1 = new Thread() {

            @Override

            public void run() {

                try {

                    lock1.lock();

                    TimeUnit.SECONDS.sleep(1);

                    lock2.lock();

                } catch (InterruptedException e) {

                    e.printStackTrace();

                }

            }

        };

        Thread t2 = new Thread() {

            @Override

            public void run() {

                try {

                    lock2.lock();

                    TimeUnit.SECONDS.sleep(1);

                    lock1.lock();

                } catch (InterruptedException e) {

                    e.printStackTrace();

                }

            }

        };


        t1.setName("mythread1");

        t2.setName("mythread2");

        t1.start();

        t2.start();

    }


    public static void main(String[] args) {

        deathLock();

    }

}
死锁日志 #
"mythread2" #12 prio=5 os_prio=0 tid=0x0000000058ef7800 nid=0x1ab4 waiting on condition [0x0000000059f8f000]

   java.lang.Thread.State: WAITING (parking)

        at sun.misc.Unsafe.park(Native Method)

        - parking to wait for  <0x00000000d602d610> (a java.util.concurrent.lock

s.ReentrantLock$NonfairSync)

        at java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)

        at java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInt

errupt(AbstractQueuedSynchronizer.java:836)

        at java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireQueued(A

bstractQueuedSynchronizer.java:870)

        at java.util.concurrent.locks.AbstractQueuedSynchronizer.acquire(Abstrac

tQueuedSynchronizer.java:1199)

        at java.util.concurrent.locks.ReentrantLock$NonfairSync.lock(ReentrantLo

ck.java:209)

        at java.util.concurrent.locks.ReentrantLock.lock(ReentrantLock.java:285)


        at DeathLock$2.run(DeathLock.java:34)


   Locked ownable synchronizers:

        - <0x00000000d602d640> (a java.util.concurrent.locks.ReentrantLock$Nonfa

irSync)


"mythread1" #11 prio=5 os_prio=0 tid=0x0000000058ef7000 nid=0x3e68 waiting on condition [0x000000005947f000]

   java.lang.Thread.State: WAITING (parking)

        at sun.misc.Unsafe.park(Native Method)

        - parking to wait for  <0x00000000d602d640> (a java.util.concurrent.lock

s.ReentrantLock$NonfairSync)

        at java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)

        at java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInt

errupt(AbstractQueuedSynchronizer.java:836)

        at java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireQueued(A

bstractQueuedSynchronizer.java:870)

        at java.util.concurrent.locks.AbstractQueuedSynchronizer.acquire(Abstrac

tQueuedSynchronizer.java:1199)

        at java.util.concurrent.locks.ReentrantLock$NonfairSync.lock(ReentrantLo

ck.java:209)

        at java.util.concurrent.locks.ReentrantLock.lock(ReentrantLock.java:285)


        at DeathLock$1.run(DeathLock.java:22)


   Locked ownable synchronizers:

        - <0x00000000d602d610> (a java.util.concurrent.locks.ReentrantLock$Nonfa

irSync)



Found one Java-level deadlock:

=============================

"mythread2":

  waiting for ownable synchronizer 0x00000000d602d610, (a java.util.concurrent.l

ocks.ReentrantLock$NonfairSync),

  which is held by "mythread1"

"mythread1":

  waiting for ownable synchronizer 0x00000000d602d640, (a java.util.concurrent.l

ocks.ReentrantLock$NonfairSync),

  which is held by "mythread2"


Java stack information for the threads listed above:

===================================================

"mythread2":

        at sun.misc.Unsafe.park(Native Method)

        - parking to wait for  <0x00000000d602d610> (a java.util.concurrent.lock

s.ReentrantLock$NonfairSync)

        at java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)

        at java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInt

errupt(AbstractQueuedSynchronizer.java:836)

        at java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireQueued(A

bstractQueuedSynchronizer.java:870)

        at java.util.concurrent.locks.AbstractQueuedSynchronizer.acquire(Abstrac

tQueuedSynchronizer.java:1199)

        at java.util.concurrent.locks.ReentrantLock$NonfairSync.lock(ReentrantLo

ck.java:209)

        at java.util.concurrent.locks.ReentrantLock.lock(ReentrantLock.java:285)


        at DeathLock$2.run(DeathLock.java:34)

"mythread1":

        at sun.misc.Unsafe.park(Native Method)

        - parking to wait for  <0x00000000d602d640> (a java.util.concurrent.lock

s.ReentrantLock$NonfairSync)

        at java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)

        at java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInt

errupt(AbstractQueuedSynchronizer.java:836)

        at java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireQueued(A

bstractQueuedSynchronizer.java:870)

        at java.util.concurrent.locks.AbstractQueuedSynchronizer.acquire(Abstrac

tQueuedSynchronizer.java:1199)

        at java.util.concurrent.locks.ReentrantLock$NonfairSync.lock(ReentrantLo

ck.java:209)

        at java.util.concurrent.locks.ReentrantLock.lock(ReentrantLock.java:285)


        at DeathLock$1.run(DeathLock.java:22)


Found 1 deadlock.
jstack检测cpu高 #

  1. 步骤一：查看cpu占用高进程

    top


Mem:  16333644k total,  9472968k used,  6860676k free,   165616k buffers

Swap:        0k total,        0k used,        0k free,  6665292k cached


  PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND

17850 root      20   0 7588m 112m  11m S 100.7  0.7  47:53.80 java

 1552 root      20   0  121m  13m 8524 S  0.7  0.1  14:37.75 AliYunDun

 3581 root      20   0 9750m 2.0g  13m S  0.7 12.9 298:30.20 java

    1 root      20   0 19360 1612 1308 S  0.0  0.0   0:00.81 init

    2 root      20   0     0    0    0 S  0.0  0.0   0:00.00 kthreadd

    3 root      RT   0     0    0    0 S  0.0  0.0   0:00.14 migration/0

  2. 步骤二：查看cpu占用高线程

    top -H -p 17850


top - 17:43:15 up 5 days,  7:31,  1 user,  load average: 0.99, 0.97, 0.91

Tasks:  32 total,   1 running,  31 sleeping,   0 stopped,   0 zombie

Cpu(s):  3.7%us,  8.9%sy,  0.0%ni, 87.4%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st

Mem:  16333644k total,  9592504k used,  6741140k free,   165700k buffers

Swap:        0k total,        0k used,        0k free,  6781620k cached


  PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND

17880 root      20   0 7588m 112m  11m R 99.9  0.7  50:47.43 java

17856 root      20   0 7588m 112m  11m S  0.3  0.7   0:02.08 java

17850 root      20   0 7588m 112m  11m S  0.0  0.7   0:00.00 java

17851 root      20   0 7588m 112m  11m S  0.0  0.7   0:00.23 java

17852 root      20   0 7588m 112m  11m S  0.0  0.7   0:02.09 java

17853 root      20   0 7588m 112m  11m S  0.0  0.7   0:02.12 java

17854 root      20   0 7588m 112m  11m S  0.0  0.7   0:02.07 java

  3. 步骤三：转换线程ID

    printf "%x\n" 17880

45d8

  4. 步骤四：定位cpu占用线程

    jstack 17850|grep 45d8 -A 30

"pool-1-thread-11" #20 prio=5 os_prio=0 tid=0x00007fc860352800 nid=0x45d8 runnable [0x00007fc8417d2000]

   java.lang.Thread.State: RUNNABLE

        at java.io.FileOutputStream.writeBytes(Native Method)

        at java.io.FileOutputStream.write(FileOutputStream.java:326)

        at java.io.BufferedOutputStream.flushBuffer(BufferedOutputStream.java:82)

        at java.io.BufferedOutputStream.flush(BufferedOutputStream.java:140)

        - locked <0x00000006c6c2e708> (a java.io.BufferedOutputStream)

        at java.io.PrintStream.write(PrintStream.java:482)

        - locked <0x00000006c6c10178> (a java.io.PrintStream)

        at sun.nio.cs.StreamEncoder.writeBytes(StreamEncoder.java:221)

        at sun.nio.cs.StreamEncoder.implFlushBuffer(StreamEncoder.java:291)

        at sun.nio.cs.StreamEncoder.flushBuffer(StreamEncoder.java:104)

        - locked <0x00000006c6c26620> (a java.io.OutputStreamWriter)

        at java.io.OutputStreamWriter.flushBuffer(OutputStreamWriter.java:185)

        at java.io.PrintStream.write(PrintStream.java:527)

        - eliminated <0x00000006c6c10178> (a java.io.PrintStream)

        at java.io.PrintStream.print(PrintStream.java:597)

        at java.io.PrintStream.println(PrintStream.java:736)

        - locked <0x00000006c6c10178> (a java.io.PrintStream)

        at com.demo.guava.HardTask.call(HardTask.java:18)

        at com.demo.guava.HardTask.call(HardTask.java:9)

        at java.util.concurrent.FutureTask.run(FutureTask.java:266)

        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)

        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)

        at java.lang.Thread.run(Thread.java:745)


"pool-1-thread-10" #19 prio=5 os_prio=0 tid=0x00007fc860345000 nid=0x45d7 waiting on condition [0x00007fc8418d3000]

   java.lang.Thread.State: WAITING (parking)

        at sun.misc.Unsafe.park(Native Method)

        - parking to wait for  <0x00000006c6c14178> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject)

        at java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)

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