Re: [Wrapper-user] Jar works with console, throws exceptions when launched via start?

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

Stas,
I have been looking into this again the last couple days.  While I
can't say that I understand it fully, I am getting closer to doing so.

If you run "ps -eo pid,ni,pri,comm" you will see the nice level along
with the priority.   The priority actually changes over time depending
on the CPU usage.  For an idle Java application, it is also different
when running a Java application using Swing vs one that is not.

If I run the Wrapper with a nice value of 10, then the Wrapper and
Java are both shifted in priority by exactly 10 as expected.

On my linux machine, running a headless Java application under the
Wrapper, the wrapper process will have a priority of 24 and java will
be 17.  Another test had it at 19 however.
If I use the generated command line to launch java directly it will
have a priority of 19.
This means that java gets a lower priority when running under the
Wrapper as you reported.

The thing that I am yet to understand is why the stand alone Java is
not getting the same priority as the Wrapper, 24.

I did some experiments with loading up Java etc and it appears to
dynamically change the priority depending on other demands on the
system.  In one test, the Wrapper had priority 24, but the java
process fluctuated between 20 and 22.

If anyone could shed some light on how this is supposed to be working
I would appreciate the input.  Ideally it would be nice if Java always
got the same default idle priority when running under the Wrapper as
when running standalone.  It does sometimes, but most of the time it
is lower.

A work around is to set the PRIORITY in the shell script to -2.  That
requires that the user be root to do so however.

Cheers,
Leif

On Thu, Aug 6, 2009 at 6:47 AM, Stas Oskin<sta...@gm...> wrote:
> Hi Leif.
>
> How are you?
>
>> Currently, the Wrapper is not doing anything special with the process
>> priorities.  It appears that the OS launches all "top-level" processes
>> at the same level.  Ie the Wrapper, or Java when run standalone.  Then
>> child processes are given a lower priority.  When Java is run under
>> the Wrapper, this means that it is getting a slightly lower priority
>> than it would if it was run standalone.
>>
>> We are looking into options to work around this.
>
> I'm looking to give a 2nd try for Tanuki wrapper - any idea if this issue
> was resolved on Linux?
>
> Thanks.

-- 
Leif Mortenson
Tanuki Software, Ltd.
6-16-7-1001 Nishi-Kasai, Edogawa-ku
Tokyo 134-0088 Japan
Tel/Fax: +81-3-3878-3211
http://www.tanukisoftware.com
lei...@ta...