Re: WAS / Webfacing performance??

Mike,
 
When it happens all the users are slow.
We also see excessive non DB paging in the *BASE pool (over the thousandth for 
as well the Faults as the Pages) whilst no considerable CPU is used. We have 
tried the stop and refresh the browser, that does not seem to have a effect.

I guess the above boils down to the GC assumption.
I'm trying to learn about how to control that (I do understand the concepts for 
GC but poor native iSeries bastards like me never had to worry about these kind 
of things, but 'progress' has reached us) but could not get straight answers.
Hope some knows more than I do and can help.

Kind regards,
Eduard,


----- Original Message ----
From: Mike Hockings <hockings@xxxxxxxxxx>
To: Websphere Development Studio Client for iSeries <wdsci-l@xxxxxxxxxxxx>
Sent: Thursday, February 15, 2007 12:02:09 PM
Subject: Re: [WDSCI-L] WAS / Webfacing performance??


Does the slowdown happen for only the single user or for all users ?   If 
it is for all users then I would suspect something like the GC but if it 
is for a single user then I would suspect browser settings or 
communications somehow.   When you see it something you might try is 
hitting stop then refresh on the browser and see if that makes it pick up 
the pace a bit.  I have also heard, indirectly, that some of this type of 
performance problems can be related to routers in the intranet needing to 
be rebooted or needing a firmware update.  But I will quickly add that I 
myself don't know how to make that sort of determination.

It would seem to me that if the performance is ok before and after the 
"slowness" that the memory you have should be sufficient. 

Mike

Mike Hockings, P.Eng.
WebSphere Development Tools for AS/400  -  CODE/Designer & WebFacing !
IBM Canada Ltd. Laboratory 
hockings@xxxxxxxxxx 
voice 905 413 3199




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Re: [WDSCI-L] WAS / Webfacing performance??






Thanks Mike and others... 

Lets start with asuming it is an garbage collection problem.....
How can we inflict GarbageCollection more often (so it has less to do).

We had already looked at other aspects like network traffic and Browser 
problems (Just because we did not want to start with pointing at the 
iSeries or WAS or Webfacing).
We could not find reasons in these for what is experienced.

Yes, we also where positively surprised with the performance of 
WAS/Webfacing on a rather slim box.

If it turns out that we need more RAM, what would be an reasonable total 
of RAM to add?
We want to be pretty sure upfront that it will bring back the problem to 
an acceptable level (5 minutes reponse time brought back to 2.5 minutes is 
a lot but is still not acceptable).

Kind regards,
Eduard,

----- Original Message ----
From: Mike Hockings <hockings@xxxxxxxxxx>
To: Websphere Development Studio Client for iSeries <wdsci-l@xxxxxxxxxxxx>
Sent: Wednesday, February 14, 2007 1:25:28 PM
Subject: Re: [WDSCI-L] WAS / Webfacing performance??


Hi Eduard,

I can think of a couple of things that might cause those symptoms, maybe. 

First of all I wonder if the starting of a session or the displaying of a 
new (busy) page may be causing the JVM to initiate garbage collection?  I 
don't know if that would cause a slowdown or not but it might.  Possibly 
getting the GC to run more often (so it has less to do) may alleviate it 
if this turns out to be the problem?

The other thing that I could think of is that it seems sometimes IE 
doesn't seem to like to play well with WAS.  I have never been able to 
definitely track this down but by setting the IE cache settings to 
"Automatic" it seems to provide the best results.  If you have to "check 
every page" you can get occasional dismal or worse response times.

Mike

Mike Hockings, P.Eng.
WebSphere Development Tools for AS/400  -  CODE/Designer & WebFacing !
IBM Canada Ltd. Laboratory 
hockings@xxxxxxxxxx 




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[WDSCI-L] WAS / Webfacing performance??






Dear all,

We have Webfaced Applications running under WAS 6.0 running on a 520 
Express (1GB RAM).
On average the performance is very good (comparable with Green Screen).
Sometimes however the performance drops and it takes minutes to get a 
response.
That happens most often when initiating a session.
Less common it happens while executing the main (larger) programs (with 
lots of fields on the screen).
There seems no relation with the total of users using the system at that 
moment.
Stopping the session and initiating a new one most often give a normal 
response time. 

When it happens we do not see a lot of CPU usage.
We do see a lot of Non DB paging.

What could be the reason/cause for this?
What can be done to get rid if it/get it under control?

Kind regards,
Eduard.