RE: Stability under HP-UX

[PELOQUIN,JEFFREY (HP-Boise,ex1)]

We have not had any problems with Tomcat on HP-UX.

What JVM are you using?

Also, here are some recommeded kernel parameters

maxusers512
nproc   2068
max_thread_proc 3000
nkthread6000
nfile   3
maxfiles2048
maxfiles_lim2048
ncallout6000
maxdsiz 2063835136

Until we made our params, similar to these values, we had severe JAVA
hotspot instability.  Granted we were using JRUN 2.3.3 at the time.

Jeff

-Original Message-
From: Allen Byington [mailto:[EMAIL PROTECTED]
Sent: Tuesday, June 10, 2003 1:27 PM
To: Tomcat Users List
Subject: Stability under HP-UX


Tomcat freezes after an indeterminate amount of time.  It just stops
responding to requests.  Doesn't time out and the process doesn't stop.
I've done everything that I can think of to stabilize this and was hoping
someone had had a similar problem with stability under hp-ux.  I've altered
the amount of memory that java is starting with up to 256MB and there was no
change.  When the process hangs, it is truly hosed and can't be killed with
anything other than a kill -9.  The kill -3 to force a coredump doesn't seem
to do anything at all and it stops writing to the logs long before I get to
kill it so there isn't an error message of any kind.  I'm desperate and
looking for ideas.  Any help that anyone could give would be greatly
appreciated.

Thanks
Allen Byington
[EMAIL PROTECTED]

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Re: Stability under HP-UX

[Tim Funk]

- Make sure your have the right patches for the OS.
- Try both 1.3, and 1.4 JVM's. In the past, it took forever to HP to deliver 
and stable 1.2, 1.3 JVM. (forever is relative to our project consistently 
barfing in the lab)
- Does using only interpreted mode do anything? ( -Xint )
- Did you check the JVM release notes from HP? They have recommended kernel 
tuning parameters.

When there is a hung state, try using glance or gpm to look at your java 
process. Make a note of number of threads, the state of the threads, memory 
usage, how the threads are blocked , number of files and sockets open as well 
as socket state. It may not solve the problem, but it may point you in the 
right direction.

Also - try turning OFF DNS on your box. Make sure you are not trying to 
resolve hostnames furing each request. The underlying C function 
gethostbyname() from the quotation I heard  is not thread scalable.

-Tim

Allen Byington wrote:
Tomcat freezes after an indeterminate amount of time.  It just stops responding to requests.  Doesn't time out and the process doesn't stop.  I've done everything that I can think of to stabilize this and was hoping someone had had a similar problem with stability under hp-ux.  I've altered the amount of memory that java is starting with up to 256MB and there was no change.  When the process hangs, it is truly hosed and can't be killed with anything other than a kill -9.  The kill -3 to force a coredump doesn't seem to do anything at all and it stops writing to the logs long before I get to kill it so there isn't an error message of any kind.  I'm desperate and looking for ideas.  Any help that anyone could give would be greatly appreciated.

Thanks
Allen Byington
[EMAIL PROTECTED]


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