Showing posts with label jps. Show all posts
Showing posts with label jps. Show all posts

Friday, June 27, 2014

Get java process heap dump and analyse it by jhat


1. Get all java processes ids
17:17 ~/java $ jps -vm
14970 Jps -vm -Dapplication.home=/usr/lib/jvm/java-7-oracle -Xms8m
8850 org.eclipse.equinox.launcher_1.3.0.v20130327-1440.jar -data /home/rivanov/workspace -os linux -ws gtk -arch x86_64 -showsplash /home/rivanov/ ..................... -Dosgi.requiredJavaVersion=1.6 -XX:MaxPermSize=256m -Xms40m -Xmx512m

2. generate heap dump for application, in my case it is Eclipse.
17:19 ~/java $ jmap -dump:format=b,file=eclipse_heap.bin 8850
Dumping heap to /home/rivanov/java/git/dmt/eclipse_heap.bin ...
Heap dump file created

3. run jhat tool from JDK to analyse heap dump.
17:19 ~/java $ jhat eclipse_heap.bin 
Reading from eclipse_heap.bin...
Dump file created Fri Jun 27 17:19:37 PDT 2014
Snapshot read, resolving...
Resolving 1548547 objects...
Chasing references, expect 309 dots.....................................................................................................................................................................................................................................................................................................................
Eliminating duplicate references.....................................................................................................................................................................................................................................................................................................................
Snapshot resolved.
Started HTTP server on port 7000
Server is ready.


4. Open in browser "http://localhost:7000/".
jhat is far from fancy heap dump analyser in comparison to Eclipse's MAT, jvisualvm, ...... but it is provided together with JDK and nothing should be installed .


Friday, February 8, 2013

Jps and jstack for java process management


Get process id:
/usr/java/bin/jps -v | grep my_app
16831 ......

Show stack of execution in process to define place of hang:
/usr/java/bin/jstack 16831


You can kill that process:
kill 16831