|
|
thread
|
|
|
===
|
|
|
|
|
|
[`thread`在线教程](https://arthas.aliyun.com/doc/arthas-tutorials.html?language=cn&id=command-thread)
|
|
|
|
|
|
> 查看当前线程信息，查看线程的堆栈
|
|
|
|
|
|
|
|
|
### 参数说明
|
|
|
|
|
|
|参数名称|参数说明|
|
|
|
|---:|:---|
|
|
|
|*id*|线程id|
|
|
|
|[n:]|指定最忙的前N个线程并打印堆栈|
|
|
|
|[b]|找出当前阻塞其他线程的线程|
|
|
|
|[i `<value>`]|指定cpu使用率统计的采样间隔，单位为毫秒，默认值为200|
|
|
|
|[--all]|显示所有匹配的线程|
|
|
|
|
|
|
### cpu使用率是如何统计出来的？
|
|
|
|
|
|
这里的cpu使用率与linux 命令`top -H -p <pid>` 的线程`%CPU`类似，一段采样间隔时间内，当前JVM里各个线程的增量cpu时间与采样间隔时间的比例。
|
|
|
|
|
|
#### 工作原理说明：
|
|
|
|
|
|
* 首先第一次采样，获取所有线程的CPU时间(调用的是`java.lang.management.ThreadMXBean#getThreadCpuTime()`及`sun.management.HotspotThreadMBean.getInternalThreadCpuTimes()`接口)
|
|
|
* 然后睡眠等待一个间隔时间（默认为200ms，可以通过`-i`指定间隔时间）
|
|
|
* 再次第二次采样，获取所有线程的CPU时间，对比两次采样数据，计算出每个线程的增量CPU时间
|
|
|
* 线程CPU使用率 = 线程增量CPU时间 / 采样间隔时间 * 100%
|
|
|
|
|
|
> 注意： 这个统计也会产生一定的开销（JDK这个接口本身开销比较大），因此会看到as的线程占用一定的百分比，为了降低统计自身的开销带来的影响，可以把采样间隔拉长一些，比如5000毫秒。
|
|
|
|
|
|
> 另外一种查看Java进程的线程cpu使用率方法：可以使用[show-busy-java-threads](https://github.com/oldratlee/useful-scripts/blob/master/docs/java.md#-show-busy-java-threads)这个脚本
|
|
|
|
|
|
### 使用参考
|
|
|
|
|
|
#### 支持一键展示当前最忙的前N个线程并打印堆栈：
|
|
|
|
|
|
```shell
|
|
|
$ thread -n 3
|
|
|
"C1 CompilerThread0" [Internal] cpuUsage=1.63% deltaTime=3ms time=1170ms
|
|
|
|
|
|
|
|
|
"arthas-command-execute" Id=23 cpuUsage=0.11% deltaTime=0ms time=401ms RUNNABLE
|
|
|
at java.management@11.0.7/sun.management.ThreadImpl.dumpThreads0(Native Method)
|
|
|
at java.management@11.0.7/sun.management.ThreadImpl.getThreadInfo(ThreadImpl.java:466)
|
|
|
at com.taobao.arthas.core.command.monitor200.ThreadCommand.processTopBusyThreads(ThreadCommand.java:199)
|
|
|
at com.taobao.arthas.core.command.monitor200.ThreadCommand.process(ThreadCommand.java:122)
|
|
|
at com.taobao.arthas.core.shell.command.impl.AnnotatedCommandImpl.process(AnnotatedCommandImpl.java:82)
|
|
|
at com.taobao.arthas.core.shell.command.impl.AnnotatedCommandImpl.access$100(AnnotatedCommandImpl.java:18)
|
|
|
at com.taobao.arthas.core.shell.command.impl.AnnotatedCommandImpl$ProcessHandler.handle(AnnotatedCommandImpl.java:111)
|
|
|
at com.taobao.arthas.core.shell.command.impl.AnnotatedCommandImpl$ProcessHandler.handle(AnnotatedCommandImpl.java:108)
|
|
|
at com.taobao.arthas.core.shell.system.impl.ProcessImpl$CommandProcessTask.run(ProcessImpl.java:385)
|
|
|
at java.base@11.0.7/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515)
|
|
|
at java.base@11.0.7/java.util.concurrent.FutureTask.run(FutureTask.java:264)
|
|
|
at java.base@11.0.7/java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:304)
|
|
|
at java.base@11.0.7/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
|
|
|
at java.base@11.0.7/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
|
|
|
at java.base@11.0.7/java.lang.Thread.run(Thread.java:834)
|
|
|
|
|
|
|
|
|
"VM Periodic Task Thread" [Internal] cpuUsage=0.07% deltaTime=0ms time=584ms
|
|
|
```
|
|
|
|
|
|
* 没有线程ID，包含`[Internal]`表示为JVM内部线程，参考[dashboard](dashboard.md)命令的介绍。
|
|
|
* `cpuUsage`为采样间隔时间内线程的CPU使用率，与[dashboard](dashboard.md)命令的数据一致。
|
|
|
* `deltaTime`为采样间隔时间内线程的增量CPU时间，小于1ms时被取整显示为0ms。
|
|
|
* `time` 线程运行总CPU时间。
|
|
|
|
|
|
注意：线程栈为第二采样结束时获取，不能表明采样间隔时间内该线程都是在处理相同的任务。建议间隔时间不要太长，可能间隔时间越大越不准确。
|
|
|
可以根据具体情况尝试指定不同的间隔时间，观察输出结果。
|
|
|
|
|
|
#### 当没有参数时，显示第一页线程的信息
|
|
|
|
|
|
默认按照CPU增量时间降序排列，只显示第一页数据。
|
|
|
|
|
|
```shell
|
|
|
$ thread
|
|
|
Threads Total: 33, NEW: 0, RUNNABLE: 9, BLOCKED: 0, WAITING: 3, TIMED_WAITING: 4, TERMINATED: 0, Internal threads: 17
|
|
|
ID NAME GROUP PRIORITY STATE %CPU DELTA_TIME TIME INTERRUPT DAEMON
|
|
|
-1 C2 CompilerThread0 - -1 - 5.06 0.010 0:0.973 false true
|
|
|
-1 C1 CompilerThread0 - -1 - 0.95 0.001 0:0.603 false true
|
|
|
23 arthas-command-execute system 5 RUNNABLE 0.17 0.000 0:0.226 false true
|
|
|
-1 VM Periodic Task Thread - -1 - 0.05 0.000 0:0.094 false true
|
|
|
-1 Sweeper thread - -1 - 0.04 0.000 0:0.011 false true
|
|
|
-1 G1 Young RemSet Sampling - -1 - 0.02 0.000 0:0.025 false true
|
|
|
12 Attach Listener system 9 RUNNABLE 0.0 0.000 0:0.022 false true
|
|
|
11 Common-Cleaner InnocuousThrea 8 TIMED_WAI 0.0 0.000 0:0.000 false true
|
|
|
3 Finalizer system 8 WAITING 0.0 0.000 0:0.000 false true
|
|
|
2 Reference Handler system 10 RUNNABLE 0.0 0.000 0:0.000 false true
|
|
|
4 Signal Dispatcher system 9 RUNNABLE 0.0 0.000 0:0.000 false true
|
|
|
15 arthas-NettyHttpTelnetBootstra system 5 RUNNABLE 0.0 0.000 0:0.029 false true
|
|
|
22 arthas-NettyHttpTelnetBootstra system 5 RUNNABLE 0.0 0.000 0:0.196 false true
|
|
|
24 arthas-NettyHttpTelnetBootstra system 5 RUNNABLE 0.0 0.000 0:0.038 false true
|
|
|
16 arthas-NettyWebsocketTtyBootst system 5 RUNNABLE 0.0 0.000 0:0.001 false true
|
|
|
17 arthas-NettyWebsocketTtyBootst system 5 RUNNABLE 0.0 0.000 0:0.001 false true
|
|
|
```
|
|
|
|
|
|
#### thread --all, 显示所有匹配的线程
|
|
|
|
|
|
显示所有匹配线程信息，有时需要获取全部JVM的线程数据进行分析。
|
|
|
|
|
|
|
|
|
#### thread id, 显示指定线程的运行堆栈
|
|
|
|
|
|
```shell
|
|
|
$ thread 1
|
|
|
"main" Id=1 WAITING on java.util.concurrent.CountDownLatch$Sync@29fafb28
|
|
|
at sun.misc.Unsafe.park(Native Method)
|
|
|
- waiting on java.util.concurrent.CountDownLatch$Sync@29fafb28
|
|
|
at java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)
|
|
|
at java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt(AbstractQueuedSynchronizer.java:836)
|
|
|
at java.util.concurrent.locks.AbstractQueuedSynchronizer.doAcquireSharedInterruptibly(AbstractQueuedSynchronizer.java:997)
|
|
|
at java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireSharedInterruptibly(AbstractQueuedSynchronizer.java:1304)
|
|
|
at java.util.concurrent.CountDownLatch.await(CountDownLatch.java:231)
|
|
|
```
|
|
|
|
|
|
#### thread -b, 找出当前阻塞其他线程的线程
|
|
|
|
|
|
有时候我们发现应用卡住了， 通常是由于某个线程拿住了某个锁， 并且其他线程都在等待这把锁造成的。 为了排查这类问题， arthas提供了`thread -b`， 一键找出那个罪魁祸首。
|
|
|
|
|
|
```bash
|
|
|
$ thread -b
|
|
|
"http-bio-8080-exec-4" Id=27 TIMED_WAITING
|
|
|
at java.lang.Thread.sleep(Native Method)
|
|
|
at test.arthas.TestThreadBlocking.doGet(TestThreadBlocking.java:22)
|
|
|
- locked java.lang.Object@725be470 <---- but blocks 4 other threads!
|
|
|
at javax.servlet.http.HttpServlet.service(HttpServlet.java:624)
|
|
|
at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
|
|
|
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
|
|
|
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
|
|
|
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
|
|
|
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
|
|
|
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
|
|
|
at test.filter.TestDurexFilter.doFilter(TestDurexFilter.java:46)
|
|
|
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
|
|
|
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
|
|
|
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)
|
|
|
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
|
|
|
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:505)
|
|
|
at com.taobao.tomcat.valves.ContextLoadFilterValve$FilterChainAdapter.doFilter(ContextLoadFilterValve.java:191)
|
|
|
at com.taobao.eagleeye.EagleEyeFilter.doFilter(EagleEyeFilter.java:81)
|
|
|
at com.taobao.tomcat.valves.ContextLoadFilterValve.invoke(ContextLoadFilterValve.java:150)
|
|
|
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:170)
|
|
|
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
|
|
|
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
|
|
|
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:429)
|
|
|
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1085)
|
|
|
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:625)
|
|
|
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:318)
|
|
|
- locked org.apache.tomcat.util.net.SocketWrapper@7127ee12
|
|
|
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
|
|
|
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
|
|
|
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
|
|
|
at java.lang.Thread.run(Thread.java:745)
|
|
|
|
|
|
Number of locked synchronizers = 1
|
|
|
- java.util.concurrent.ThreadPoolExecutor$Worker@31a6493e
|
|
|
```
|
|
|
|
|
|
> 注意， 目前只支持找出synchronized关键字阻塞住的线程， 如果是`java.util.concurrent.Lock`， 目前还不支持。
|
|
|
|
|
|
|
|
|
#### thread -i, 指定采样时间间隔
|
|
|
|
|
|
* `thread -i 1000` : 统计最近1000ms内的线程CPU时间。
|
|
|
|
|
|
* `thread -n 3 -i 1000` : 列出1000ms内最忙的3个线程栈
|
|
|
|
|
|
```bash
|
|
|
$ thread -n 3 -i 1000
|
|
|
"as-command-execute-daemon" Id=4759 cpuUsage=23% RUNNABLE
|
|
|
at sun.management.ThreadImpl.dumpThreads0(Native Method)
|
|
|
at sun.management.ThreadImpl.getThreadInfo(ThreadImpl.java:440)
|
|
|
at com.taobao.arthas.core.command.monitor200.ThreadCommand.processTopBusyThreads(ThreadCommand.java:133)
|
|
|
at com.taobao.arthas.core.command.monitor200.ThreadCommand.process(ThreadCommand.java:79)
|
|
|
at com.taobao.arthas.core.shell.command.impl.AnnotatedCommandImpl.process(AnnotatedCommandImpl.java:96)
|
|
|
at com.taobao.arthas.core.shell.command.impl.AnnotatedCommandImpl.access$100(AnnotatedCommandImpl.java:27)
|
|
|
at com.taobao.arthas.core.shell.command.impl.AnnotatedCommandImpl$ProcessHandler.handle(AnnotatedCommandImpl.java:125)
|
|
|
at com.taobao.arthas.core.shell.command.impl.AnnotatedCommandImpl$ProcessHandler.handle(AnnotatedCommandImpl.java:122)
|
|
|
at com.taobao.arthas.core.shell.system.impl.ProcessImpl$CommandProcessTask.run(ProcessImpl.java:332)
|
|
|
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
|
|
|
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
|
|
|
at java.lang.Thread.run(Thread.java:756)
|
|
|
|
|
|
Number of locked synchronizers = 1
|
|
|
- java.util.concurrent.ThreadPoolExecutor$Worker@546aeec1
|
|
|
...
|
|
|
```
|
|
|
|
|
|
#### thread --state ，查看指定状态的线程
|
|
|
|
|
|
```bash
|
|
|
[arthas@28114]$ thread --state WAITING
|
|
|
Threads Total: 16, NEW: 0, RUNNABLE: 9, BLOCKED: 0, WAITING: 3, TIMED_WAITING: 4, TERMINATED: 0
|
|
|
ID NAME GROUP PRIORITY STATE %CPU DELTA_TIME TIME INTERRUPTE DAEMON
|
|
|
3 Finalizer system 8 WAITING 0.0 0.000 0:0.000 false true
|
|
|
20 arthas-UserStat system 9 WAITING 0.0 0.000 0:0.001 false true
|
|
|
14 arthas-timer system 9 WAITING 0.0 0.000 0:0.000 false true
|
|
|
```
|