Re: load distribution to kio vps or hash PN_ID
On Jul 28, 1:36 pm, "Art Kagel" <art.ka...@gmail.com> wrote:
> The KIO threads each run in one of the CPU VPs and ONLY service IO requests
> from threads running in that specific CPU VP.
>
> The only way to spread the load better between the CPU VPs is to properly
> tune your listener/poll threads (NETTYPE). If you are using mostly TCP
> connections then the listener threads should be running on one or more NET
> VPs (so that a maximum of 200 connections are configured or actually used
> per NET VP with one of two SHM poll threads configured in CPU VPs. If you
> are using shared memory mostly, you should configure an SHM poll thread in
> EVERY CPU VP with enough connections per thread so that the product of the
> number of connections and the number of threads is at least the maximum
> number of concurrent SHM connections. I've posted the reasons for this many
> times. You can find one such explanation in the Informix FAQ.
>
> Art
>
>
>
>
>
> On Mon, Jul 28, 2008 at 3:45 PM, Mohit <mohitanch...@gmail.com> wrote:
> > IDS: 11.10.FC2
>
> > I am seeing slow performance and when I look at onstat -g iov I see
> > that out of 28 kio vp only 2 are super busy. Below is the snapshot
> > (first 2 have 107 and 136 io/s):
> > kio 0 i 107.7 27388858 15142656 12246202 0 45203359
> > 0.6 0 0
> > kio 1 s 136.3 34657932 17039436 17618496 0 58688558
> > 0.6 0 0
> > kio 2 i 51.9 13185483 6749584 6435899 0 16702456
> > 0.8 0 0
> > kio 3 i 35.0 8892769 3926884 4965885 0 9802816
> > 0.9 0 0
> > kio 4 b 61.1 15527901 8149519 7378382 0 20701725
> > 0.8 0 0
> > kio 5 i 29.8 7566669 3218713 4347956 0 8108678
> > 0.9 0 0
> > kio 6 s 46.6 11841344 5811843 6029501 0 14454630
> > 0.8 0 0
> > kio 7 b 26.6 6772413 2641624 4130789 0 7476973
> > 0.9 0 0
> > kio 8 i 43.4 11041033 5137391 5903642 0 13220738
> > 0.8 0 0
> > kio 9 i 32.8 8343696 3752504 4591192 0 9292855
> > 0.9 0 0
> > kio 10 s 31.8 8090050 3505154 4584896 0 8745305
> > 0.9 0 0
>
> > VPCLASS settings are cpu,num=28,aff=4-31,noage
>
> > I don't really understand why would the load not get distributed or is
> > that really a problem why I could be seeing the performance
> > degradation. I looked at the SQLTRACE also and came up with only one
> > table that might be slowing down the performance. But, still output of
> > onstat -g iov is rather unusual than I am used to seeing. Any> > suggestion on where I should look at the reason of this anomaly
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>
> --
> Art S. Kagel
> Oninit (www.oninit.com)
> IIUG Board of Directors (a...@iiug.org)
>
> Disclaimer: Please keep in mind that my own opinions are my own opinions and
> do not reflect on my employer, Oninit, the IIUG, nor any other organization
> with which I am associated either explicitly or implicitly. Neither do those
> opinions reflect those of other individuals affiliated with any entity with
> which I am affiliated nor those of the entities themselves.- Hide quoted text -
>
> - Show quoted text -
When number of CPU vps are increased or a table fragments are
increased do we also need to increase PC_HASHSIZE, DS_HASHSIZE or
DD_HASHSIZE. I see mutex waits on "hash PN_ID". I don't really
understand the relation