Out Of Memory ???

[dhanish]

Hi,
I am getting Java.Lang Out of Memory error when i run one of my application.Any clues ...what kernel params govern this or any other settings like ulimit and other things are reqd.
But i am not getting this error on the other machine having the same kernel param settings.

Any suggestions

thnks

[Steven Gillard_2]

Could be a few things:

1. You have hit a memory limit like maxdsiz or shmmax.

2. Your system does not have enough reservable swap space for the amount of memory the Java process wants. Check the available swap space with 'swapinfo -atm'.

3. You are starting a lot of threads in your Java app and are hitting max_thread_proc or nkthread.

The most common cause is number 3, because by default max_thread_proc is quite small and large java apps usually need a lot more. I suggest you increase max_thread_proc, and perhaps maxdsiz, shmmax and nkthread as well depending on what their current values are.

Also have a look at the Java FAQ:

http://www.hp.com/products1/unix/java/java2/sdkrte1_3/faq.html

Regards,
Steve

[dhanish]

My kernel setting for
maxdsiz =0xC0000000
max_thread_proc =512
and swap info o/p is given below...


TYPE AVAIL USED FREE USED LIMIT RESERVE PRI NAME
dev 1024 0 1024 0% 0 - 1 /dev/vg00/lvol2
dev 1000 0 1000 0% 0 - 0 /dev/vg00/lvol10
dev 1000 0 1000 0% 0 - 0 /dev/vg01/lvol18
dev 3000 0 3000 0% 0 - 0 /dev/vg01/lvol120
reserve - 1726 -1726
memory 13312 1539 11773 12%
total 19336 3265 16071 17% - 0

[Steven Gillard_2]

What about shmmax? I think Java uses a private mmap segment for its heap which is why I ask.

It might also help to get a tusc trace of the failing process, that way we'll know which system call is failing and what the errno value is.

Regards,
Steve

[Olav Baadsvik]

Hi,

Things to check:

1. What heap-size do you specify when
you start the java application?
2. Required patches for java insalled?
You may download the HPjconfig tool
to check the patch-level and kernel
parameters. Download from www.hp.com/go/java
3. Check what arguments that are used
when starting java. I have seen
this option used:
-XX:+DisableExplicitGC which very
easily will give the error you see.

Regards
Olav

[dhanish]

My settings for shmmax:0x40000000

[Steven Gillard_2]

Can you get a tusc trace? You can get tusc from:

http://hpux.connect.org.uk/hppd/hpux/Sysadmin/tusc-7.2/

Regards,
Steve

[Carlos Fernandez Riera]

I think this URL will be very interesting for you.

[Carlos Fernandez Riera]

I think this URL will be very interesting for you.

http://dsportal.eservices.hp.com/dspp/tech/tech_TechDocumentDetailPage_IDX/1,1701,1608,00.html

[dhanish]

Exception in thread "main" java.lang.OutOfMemoryError
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is this error related to memeory.

[Bill Hassell]

Most likely you are running 32bit applications and these are severely constrained on memory addressing. This includes having to share a highly fragmented memory space for shared memory. Read the 2 memory and process management documents in /usr/share/doc. Then get a copy of shminfo from:

ftp://contrib:9unsupp8@hprc.external.hp.com/sysadmin/programs/shminfo/