In one of my web applications there is an issue:
I want to check whether objects are properly initialized or not.
For that I want to extract a memory dump and analyse it . How can I take a memory dump in Tomcat and analyse it ?
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(1) Get Tomcat (Bootstrap) process ID by jps command
# jps
24717 Jps
3652 Bootstrap
3737 DirectoryServer
(2) Run jmap command
# jmap -dump:format=b,file=./heapdump.hprof 3652
(3) Download Memory Analyzer (MAT)
(4) Open heapdump.hprof by MAT
Kohei TAMURA
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Will jmap hang tomcat or kill/stop tomcat ? I want to take dump in running application. – user1846749 May 01 '17 at 13:06
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No. You can do it in running application. – Kohei TAMURA May 01 '17 at 13:44
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And shall I stop the app manually ? If I stop then there is no way to get the heap dump of stopped app since no heap is in memory for that process now. Does jmap will internally stop/terminate the app ? – user1846749 May 02 '17 at 02:56
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No. Heap dump can be got during running app. – Kohei TAMURA May 02 '17 at 06:05
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How in running app ?http://stackoverflow.com/questions/5287010/is-jvm-stopped-while-executing-jmap - jmap stops running application here. – user1846749 May 03 '17 at 00:10
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Your application cannot response as usual while running jmap but the process is not killed. – Kohei TAMURA May 03 '17 at 02:12
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any alternative to jmap ? – user1846749 May 04 '17 at 06:39