IDS Forum

Re: MSC virtual-processor class too loaded aft....

Posted By: Marc Patino
Date: Tuesday, 24 February 2009, at 2:26 p.m.

In Response To: Re: MSC virtual-processor class too loaded aft.... (JACQUES RENAUT)

Hi,

Thank you Jacques for your answers. Their are very useful for me to grow my
knowledge of this great DB Engine (I am a Unix/Linux sysadmin that is
begining to learn IDS)

At the time that I made the onstat -g iov ... there were one or two users
connected to the engine.

Fortunately, the msc vp high usage is over. I don't know (at the moment) the
reason, but I think that problem is related with the following:

After migrating the server (DSS) from 10FC9 to 11.5FC3 we have a performance
issue with a process that loads data from our OLTP server ( SLES 10 SP2 IDS
10FC9) to our DSS (DWH) server (SLES 10 SP2 IDS 11.5FC3, which has this msc
load problems). This process has a function that makes some selects via
synonims against to our OLTP server, after some work we found that the
select via synonims was the clue of this poor performance. Then, we stop
using this synonim inside the procedure, the performance issue stopped and
since this time, our msc vp are not high loaded.

I open a PMR on IBM support about this problem. I don't know if I am on the
right way, but at the moment I don't have any other clue. With IDS 10FC9 on
our DSS server we never had this kind of problem.

Tomorrow, I will try to reproduce this problem in our development eviroment.

Excused my poor english :)

Regards,

Marc

On Tue, Feb 24, 2009 at 7:45 PM, JACQUES RENAUT <jrenaut@us.ibm.com> wrote:

> Do you have clients connect to the engine and not do any work, or just
> disconnect? It just strikes me as very odd that the server has only been up
> 54
> minutes, but 1 of the msc vp has consumed ~2200 seconds of user cpu time,
> while your cpu vps have done practialy nothing. For that to happen it seems
> like you would have to have clients connecting to the engine and then just
> disconnect which would cause the msc vp to go through it's work of
> authenticating the connection, but then have new connection disconnect
> without
> doing anything. On my 11.50 instance 1 new network connection client caused
> my
> msc vp to do 5 msc vps ops as shown by onstat -g ioq. I would guess that
> may
> somewhat vary based on how your clients have to authenticate.
>
> Also for it to be able to do the ~400ish ops per second, it seems like
> whatever op it is doing wouldn't be very time consuming, but it's getting
> bombed with a lot of op requests. If your system has a pstack type command
> that you could run against the pid of the msc vp, you might run that a
> couple
> times in a row to get the stack trace for the msc vp, and if it was always
> the
> same that might be some sort of indications of what it is doing that might
> be
> consuming the user cpu time.
>
> I guess it might also be interesting to look at your onstat -g ntd to see
> if
> you do have any client type that has a really high number of accepted count
> which might be the client type that's causing the work the msc vp is doing.
>
>
>
> *******************************************************************************
> Forum Note: Use "Reply" to post a response in the discussion forum.
>
>

--000e0cd25cfaf15c2e0463af16eb

Messages In This Thread

• MSC virtual-processor class too loaded after migra
  Marc Patino -- Tuesday, 24 February 2009, at 7:59 a.m.
  • Re: MSC virtual-processor class too loaded after m
    JACQUES RENAUT -- Tuesday, 24 February 2009, at 11:51 a.m.
  • Re: MSC virtual-processor class too loaded after m
    John Miller iii -- Tuesday, 24 February 2009, at 12:02 p.m.
    • Re: MSC virtual-processor class too loaded aft....
      Marc Patino -- Tuesday, 24 February 2009, at 12:25 p.m.
      • Re: MSC virtual-processor class too loaded aft....
        JACQUES RENAUT -- Tuesday, 24 February 2009, at 1:45 p.m.
        • Re: MSC virtual-processor class too loaded aft....
          Marc Patino -- Tuesday, 24 February 2009, at 2:26 p.m.

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