diff --git a/site/src/site/sphinx/en/thread.md b/site/src/site/sphinx/en/thread.md new file mode 100644 index 000000000..7c9b4b9cd --- /dev/null +++ b/site/src/site/sphinx/en/thread.md @@ -0,0 +1,166 @@ +thread +====== + +Check the basic profile and stack trace of the threads. + +### Parameters + +|Name|Specification| +|---:|:---| +|*id*|thread id in JVM| +|[n:]|the top n busiest with stack traces| +|[b]|locate the threads blocking others| +|[i ``]|specify the interval to collect data to compute CPU ratios (ms)| + +How to get the CPU ratios? + +> Within an *specified* interval, the time cost by the thread compared to the total CPU time. +> Take a sample (using `java.lang.management.ThreadMXBean#getThreadCpuTime`) to get the CPU time cost for all the threads and after a *specified* interval (default *100 ms*, which can be specified by `-i`), take another sample and we have the CPU time cost and the ratios naturally. + +> Attention: this kind of operation will take time, to decrease the extra cost, you'd better expand the interval to like `5000 ms` for less performance overhead. + +F.Y.I + +If you'd like to check the CPU ratios from the very start of the Java process, [show-busy-java-threads](https://github.com/oldratlee/useful-scripts/blob/master/docs/java.md#-show-busy-java-threads) can be a help. + +### Usage + +#### List the top n busiest with detailed stack trace + +```shell +$ thread -n 3 +"as-command-execute-daemon" Id=29 cpuUsage=75% RUNNABLE + at sun.management.ThreadImpl.dumpThreads0(Native Method) + at sun.management.ThreadImpl.getThreadInfo(ThreadImpl.java:440) + at com.taobao.arthas.core.command.monitor200.ThreadCommand$1.action(ThreadCommand.java:58) + at com.taobao.arthas.core.command.handler.AbstractCommandHandler.execute(AbstractCommandHandler.java:238) + at com.taobao.arthas.core.command.handler.DefaultCommandHandler.handleCommand(DefaultCommandHandler.java:67) + at com.taobao.arthas.core.server.ArthasServer$4.run(ArthasServer.java:276) + at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) + at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) + at java.lang.Thread.run(Thread.java:745) + + Number of locked synchronizers = 1 + - java.util.concurrent.ThreadPoolExecutor$Worker@6cd0b6f8 + + + +"as-session-expire-daemon" Id=25 cpuUsage=24% TIMED_WAITING + at java.lang.Thread.sleep(Native Method) + at com.taobao.arthas.core.server.DefaultSessionManager$2.run(DefaultSessionManager.java:85) + + + +"Reference Handler" Id=2 cpuUsage=0% WAITING on java.lang.ref.Reference$Lock@69ba0f27 + at java.lang.Object.wait(Native Method) + - waiting on java.lang.ref.Reference$Lock@69ba0f27 + at java.lang.Object.wait(Object.java:503) + at java.lang.ref.Reference$ReferenceHandler.run(Reference.java:133) +``` + +#### List all info when no options provided + +```shell +$ thread +Threads Total: 16, NEW: 0, RUNNABLE: 7, BLOCKED: 0, WAITING: 5, TIMED_WAITING: 4, TERMINATED: 0 +ID NAME GROUP PRIORITY STATE %CPU TIME INTERRUPTE DAEMON +30 as-command-execute-daemon system 9 RUNNABLE 72 0:0 false true +23 as-session-expire-daemon system 9 TIMED_WAIT 27 0:0 false true +22 Attach Listener system 9 RUNNABLE 0 0:0 false true +11 pool-2-thread-1 main 5 TIMED_WAIT 0 0:0 false false +12 Thread-2 main 5 RUNNABLE 0 0:0 false true +13 pool-3-thread-1 main 5 TIMED_WAIT 0 0:0 false false +25 as-selector-daemon system 9 RUNNABLE 0 0:0 false true +14 Thread-3 main 5 TIMED_WAIT 0 0:0 false false +26 pool-5-thread-1 system 5 WAITING 0 0:0 false false +15 Thread-4 main 5 RUNNABLE 0 0:0 false false +1 main main 5 WAITING 0 0:2 false false +2 Reference Handler system 10 WAITING 0 0:0 false true +3 Finalizer system 8 WAITING 0 0:0 false true +4 Signal Dispatcher system 9 RUNNABLE 0 0:0 false true +20 NonBlockingInputStreamThread main 5 WAITING 0 0:0 false true +21 Thread-8 main 5 RUNNABLE 0 0:0 false true +``` + +#### thread present the specified thread profile + +```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 locate the blocking threads + +Using `-b`, we can effectively locate the threads holding locks blocking other threads resulting in a frozen system. + +```sh +$ 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 +``` + +> Attention: only `synchronized` blocked threads can be located for now, `JUL` not supported yet. + + +#### thread -i specify the collecting interval + +```sh +$ 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 +... +```