【Java命令三】jstack

jstack是用于获得当前运行的Java程序所有的线程的运行情况(thread dump），不同于jmap用于获得memory dump

 

[hadoop@hadoop sbin]$ jstack
Usage:
    jstack [-l] <pid>
        (to connect to running process)
    jstack -F [-m] [-l] <pid>
        (to connect to a hung process)
    jstack [-m] [-l] <executable> <core>
        (to connect to a core file)
    jstack [-m] [-l] [server_id@]<remote server IP or hostname>
        (to connect to a remote debug server)

Options:
    -F  to force a thread dump. Use when jstack <pid> does not respond (process is hung)
    -m  to print both java and native frames (mixed mode)
    -l  long listing. Prints additional information about locks
    -h or -help to print this help message

 

 常用参数：-F和-l，-F用于强制dump，-l用于获取一些关于锁的详细信息

 

 样例：

如下是使用jstack -l pid > thread.dump.001获得的输出，其中Locked ownable synchronizers是-l产生的，不加-l参数则不会输出

2015-02-27 05:37:00
Full thread dump Java HotSpot(TM) 64-Bit Server VM (24.65-b04 mixed mode):

"sparkMaster-akka.remote.default-remote-dispatcher-55" daemon prio=10 tid=0x00007ff990001800 nid=0xc03 waiting on condition [0x00007ff9ad5d2000]
   java.lang.Thread.State: TIMED_WAITING (parking)
        at sun.misc.Unsafe.park(Native Method)
        - parking to wait for  <0x00000000fd77df70> (a akka.dispatch.ForkJoinExecutorConfigurator$AkkaForkJoinPool)
        at scala.concurrent.forkjoin.ForkJoinPool.idleAwaitWork(ForkJoinPool.java:2135)
        at scala.concurrent.forkjoin.ForkJoinPool.scan(ForkJoinPool.java:2067)
        at scala.concurrent.forkjoin.ForkJoinPool.runWorker(ForkJoinPool.java:1979)
        at scala.concurrent.forkjoin.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:107)

   Locked ownable synchronizers:
        - None

"sparkMaster-akka.actor.default-dispatcher-46" daemon prio=10 tid=0x00007ff988008000 nid=0xb2a waiting on condition [0x00007ff9adad7000]
   java.lang.Thread.State: WAITING (parking)
        at sun.misc.Unsafe.park(Native Method)
        - parking to wait for  <0x00000000fd77ed20> (a akka.dispatch.ForkJoinExecutorConfigurator$AkkaForkJoinPool)
        at scala.concurrent.forkjoin.ForkJoinPool.scan(ForkJoinPool.java:2075)
        at scala.concurrent.forkjoin.ForkJoinPool.runWorker(ForkJoinPool.java:1979)
        at scala.concurrent.forkjoin.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:107)

   Locked ownable synchronizers:
        - None

"Attach Listener" daemon prio=10 tid=0x00007ff9a800d800 nid=0x995 waiting on condition [0x0000000000000000]
   java.lang.Thread.State: RUNNABLE

   Locked ownable synchronizers:
        - None

"qtp984535779-33" daemon prio=10 tid=0x00007ff98c078800 nid=0x833 waiting on condition [0x00007ff9ac2a3000]
   java.lang.Thread.State: TIMED_WAITING (parking)
        at sun.misc.Unsafe.park(Native Method)
        - parking to wait for  <0x00000000fd781130> (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 org.eclipse.jetty.util.BlockingArrayQueue.poll(BlockingArrayQueue.java:342)
        at org.eclipse.jetty.util.thread.QueuedThreadPool.idleJobPoll(QueuedThreadPool.java:526)
        at org.eclipse.jetty.util.thread.QueuedThreadPool.access$600(QueuedThreadPool.java:44)
        at org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:572)