Memory usage of a Single process too High in HP-UX

[Md. Minhaz Khan]

Dear All,

As i know, "VSS" is the total size of a process image & "RSS" is the size of the image
actually in physical memory at that moment.


From "glance" output i have found one "java" process have RSS=4.59gb & VSS=9.20gb but in my system below is the setting for
kernel parameters:

1) maxdsiz = 1073741824 = 1 GB
2) maxdsiz_64bit = 2147483648 = 2GB
3) maxssiz = 134217728 = 128MB
4) maxssiz_64bit = 1073741824 = 1GB


My query is i have limit maximum memory of a single process = 2GB (For 64 bit,maxdsiz_64bit = 2147483648 = 2GB )

Why this java process eats "4.6" GB memory??

I have attached "kmeminfo -user" & "kcusage" command output with this thread

*Note: Model of my server is "rx8640" & OS Version=B.11.23

Thanks
Minhaz

[SoorajCleris]

http://docs.hp.com/en/JAVAPROGUIDE/diag_memory_leaks.html

[Dennis Handly]

>Why this java process eats 4.6 GB memory?

Have you had maxdsiz_64bit that small for some time?

Perhaps the Java process is using shared memory, which ignores maxdsiz_64bit.

[Md. Minhaz Khan]

Dear Dennins,

JAVA process doesn't use any shared memory.Please see "ipcs -ma" & "ps -ef|grep java"command output attached with this mail.

Anybody can give me the exact reason why JAVA process eats so much memory???

Thanks
Minhaz

[Md. Minhaz Khan]

One more thing, this "JAVA" process is not a zombie process. This process is used to "select data from two or three tables & then insert that data into another table".

Thanks
Minhaz

[Duncan Edmonstone]

Minhaz,

If you go to the process memory screen in glance it will tell you what memory is being used for the various regions...

glance -M

then when prompted enter the process ID of your java proc...

What do you see there?

HTH

Duncan

[Dennis Handly]

>JAVA process doesn't use any shared memory. Please see "ipcs -ma" & "ps -ef|grep java"command output attached with this mail.

You can't tell if java is using shared memory. The only thing you can tell is that the shared memory doesn't add up to 2.6 Gb.

>Anybody can give me the exact reason why JAVA process eats so much memory?

Unless you recently lowered maxdsiz_64bit, there must be something wrong with glance and kmeminfo?
You need to cross check with top and ps.

[Don Morris_1 · Accepted solution]

Since you have kmeminfo -- `kmeminfo -pid 25219`, `kmeminfo -pid 25162`, etc. for any processes you want a detailed breakdown on.

As to your question itself, objects created via mmap() [file or anonymous, Shared or Private] which have pages instantiated will show in the Physical count and have nothing to do with maxdsiz. So my expectation since ipcs doesn't indicate too large of SysV SHMEM objects (which is one of the other possibilities as Dennis indicated) would be you either have large shared libraries or java is implementing some private data space using a MAP_PRIVATE|MAP_ANONYMOUS object.

Similarly, Glance would have reported the object type breakdown, or you could have used pstat interfaces to write a program (or get someone else's) to examine it. No reason to re-invent the wheel since you have kmeminfo and Glance, though.

[Steven E. Protter]

Shalom Minhaz,

Take a look at the process with glance.

You will find the process is using memory from multiple memory regions.

Also, there is a big hole, large enough to drive a semi truck through, that processes can use to take temporary memory. It is not one of the regulated memory areas.

We ran into this with oracle. Certain oracle reports were chewing up 18 GB of memory on a system that had single process limits set at 4 GB.

The good news here is Oracle admitted it was a bug and gave us a fix for the problem. You may find a patch to java will resolve this issue.

SEP

[Md. Minhaz Khan]

Thanks a lot everybody for valuable information.
----Minhaz