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Memory dump with jmap and jhat

jmap tool is for printing memory maps of a given process. For 64 bit systems -J-d64 option may be used. jhat tool is for parsing a heap dump file and launching webserver. In the following script jmap dumps memory map to a file then jhat reads dump file and serve it from web using port 7000.

#!/bin/bash
process_id=$(ps ax |grep org.jboss. |grep -v grep |awk '{print $1}')

snapshot_time=$(date +%H_%M)
jmap -J-d64 -heap $process_id > /opt/jboss/$process_id-$snapshot_time.jmap

jmap -J-d64 -F -dump:file="/opt/jboss/$process_id-$snapshot_time.dmp" $process_id
jhat -J-mx512m -stack false /opt/jboss/$process_id-$snapshot_time.dmp

script output looks like similar:
-----------------------------------------------
Attaching to process ID 10382, please wait...
Debugger attached successfully.
Server compiler detected.
JVM version is 20.4-b02
Attaching to process ID 10382, please wait...
Debugger attached successfully.
Server compiler detected.
JVM version is 20.4-b02
Dumping heap to /opt/jboss/10382-14_53.dmp ...

Finding object size using Printezis bits and skipping over...
Finding object size using Printezis bits and skipping over...
Finding object size using Printezis bits and skipping over...
Finding object size using Printezis bits and skipping over...

Heap dump file created
14:56:01,182 INFO  [org.jenkinsci.plugins.gravatar.GravatarCheckAsyncPeriodicWork] (Gravatar periodic lookup thread) Started Gravatar periodic lookup
14:56:01,185 INFO  [org.jenkinsci.plugins.gravatar.GravatarCheckAsyncPeriodicWork] (Gravatar periodic lookup thread) Finished Gravatar periodic lookup. 1 ms
Reading from /opt/jboss/10382-14_53.dmp...
Dump file created Wed Jan 18 14:53:07 EET 2012

WARNING:  Failed to resolve object id 0xf5b931f8 for field hb (signature L)
Chasing references, expect 359 dots..............................................................................................................
Eliminating duplicate references........................................................................................................
Snapshot resolved.
Started HTTP server on port 7000
Server is ready.

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