RE: PASE experts wanted

date: Mon, 24 Mar 2008 21:04:07 -0400
from: Jon Paris <Jon.Paris@xxxxxxxxxxxxxx>
subject: PASE experts wanted

Can somebody tell me what storage pool is used for PASE jobs?

Hi Jon

Since the PASE environment is, as I recall, mini AIX box within an
AS/400, the PASE environment doesn't play by the same rules as regular
apps (non-tagged pointers, flat memory model, yadda, yadda...) I'm not
sure if the same storage pool rules apply.

In the past, when I had to debug and performance model PASE apps, I had
to put a UNIX admin's cap on and start looking at the process as it
executes within PASE. That was a few years ago, however-- there may be
better performance monitoring tools available.

I'm having a performance issue with some jobs in PASE and wonder if
it is possible/desirable to give them their own "playground" and if
so how. Or should auto tune be taking care of this for me?

Auto tune should be managing the "shell" of the environment-- I do not
know if it actually jumps the wall and tunes the specific processes
within PASE.

Reason for asking is that I'm seeing only about 50% CPU usage
(WRKSYSSTS) and almost no page faults - yet the job is running
slowly. I am trying to get my head around this whole PASE thing, but
the tools I'm familiar with to help me review what is going on don't
seem to be helping - there must for example be a way to see what PASE
jobs are running, but I'm danged if I can find it. Anyone point me
to an Idiots Guide to PASE?

What sort of app is it? What's the app written in? How was it migrated
to the AS/400 box? Was it compiled specifically for PASE? (there are
compiler options to ensure quadword alignment, which is really
important; an application shouldn't run if it isn't properly compiled,
but we were using third party AIX drivers that weren't compiled
quadword-aligned and they worked just fine.)

One of the worst performance issues was data sourcing-- we were sucking
data from the QSYS file system, and there's an impact there when it
comes to database connections, codepage translation, etc. That may be a
performance impact.

From what I remember the version of the AIX runtime, and the runtime

libraries, that are deployed in PASE are about 18 months behind the
current release you'd find on an AIX box-- I remember an IBMer telling
me that they wanted to use a rock-solid version of AIX in PASE, rather
than having to do double-duty with AIX fixes, so PASE's runtime is
always one release behind.

Sorry, this probably isn't a great deal of help.

-Doc


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