/jstack-profiler

Simple java profiler that take jstack output as input

Primary LanguageScala

Build Status

Jstack Profiler

Simple profiler that takes concatenation of jstack's output as input. It's useful, when you want to find out what's going on a production server that you can't stop or profile (with classic profiler).

How to compile

$ sbt assembly

It generates a big jar file in the target directory

How to use

First generate a full thread dump output every n seconds (60 sec in this example), append those thread dumps in a file (jstack.log in this example). Ctrl+C to terminate

$ while true ; do jstack PID >> jstack.log ; sleep 60 ; done

Then launch the analyze with:

$ cat jstack.log | java -jar target/jstack-profiler-assembly-0.2.jar

Here is an example of the output:

Runnable methods breakout
-------------------------
rank    time    name
0       82.50%  java.lang.Thread.run(Thread.java:722)
1       80.00%  sun.nio.ch.SelectorImpl.select(SelectorImpl.java:98)
2       11.79%  org.jboss.netty.util.internal.DeadLockProofWorker$1.run(DeadLockProofWorker.java:42)
3       11.43%  sun.nio.ch.SelectorImpl.lockAndDoSelect(SelectorImpl.java:69)
4       2.86%   org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:582)
5       2.50%   sun.nio.ch.EPollArrayWrapper.poll(EPollArrayWrapper.java:228)
6       1.79%   org.springframework.jdbc.core.JdbcTemplate$3.doInPreparedStatement(JdbcTemplate.java:844)
7       0.71%   java.net.SocketInputStream.socketRead0(Native Method)
8       0.36%   com.google.gson.stream.JsonWriter.string(JsonWriter.java:535)

Blocked/Waiting methods breakout
--------------------------------
rank    time    name
0       41.96%  com.example.service.run(Servie.java:123)
1       24.22%  sun.misc.Unsafe.park(Native Method)
2       12.61%  java.lang.Thread.run(Thread.java:722)
3       11.83%  java.util.concurrent.ThreadPoolExecutor.getTask(ThreadPoolExecutor.java:1043)
4       10.27%  java.util.concurrent.locks.LockSupport.parkNanos(LockSupport.java:226)
5       5.80%   java.util.concurrent.LinkedBlockingDeque.takeFirst(LinkedBlockingDeque.java:440)
6       4.13%   com.google.common.cache.LocalCache.get(LocalCache.java:3980)
7       2.68%   com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:534)
8       1.56%   java.util.concurrent.ScheduledThreadPoolExecutor$DelayedWorkQueue.take(ScheduledThreadPoolExecutor.java:807)
9       1.45%   java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:907)
10      1.34%   java.util.concurrent.SynchronousQueue$TransferStack.awaitFulfill(SynchronousQueue.java:424)
11      0.78%   com.google.common.cache.LocalCache$Segment.waitForLoadingValue(LocalCache.java:2333)
12      0.11%   java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:118)