Re: [Wrapper-user] JVM hang - Xms / Xmx

[Leif M. <le...@ta...>]

Paul,

Paul Casanova wrote:

>We've had problems with our JVM hanging from time to time.  The Wrapper
>restarted it each time faithfully, which saved heartache and downtime.
>
>I started looking into the initial / maximum heap values, and while I
>couldn't find much info about how they relate to garbage collection, there
>were comments that suggested setting them to different values (rather than
>the same).  I did this, and the JVM hasn't hung in the past 3 weeks - which
>is fantastic!
>  
>
Thanks for commenting on that.  I don't usually set the initial and max 
heap values to
the same thing.  But I have seen config files from users in the past 
which have done so.

Where did you see that?  It may make sense to place a warning in the 
documentation
as something to keep an eye out for.

>Has this worked for anyone else - or is anyone else having JVM hanging
>issues?
>
>What I have noticed is that we are now getting
>INFO   | jvm 1    | 2004/03/31 12:26:33 | java.lang.OutOfMemoryError
>  
>
What are the values that you are using for your initial and max heap 
sizes?   My
obvious answer is that it appears that your application is running out 
of memory.
But that would be too obvious.

When you modified the values for the max and init heap sizes are you 
sure that
you do not have any typos that would be causing the wrapper to use the 
defaults.
Check the command used to launch java at the top of the wrapper log with 
debug
output enabled.  Make sure they are what you expect.

How long has your application been running when you encounter this problem?
Does there appear to be a memory leak in the application?   I can't think of
any reason why this would be working with the init and max heap sizes set to
the same values, but not working when they differ...

I'll think about this more after I hear back from you.

Cheers,
Leif