IDS Forum

Re: WARNING! Physical Log size 140000 is too s....

Posted By: John Miller iii
Date: Monday, 29 November 2010, at 3:19 p.m.

In Response To: Re: WARNING! Physical Log size 140000 is too s.... (Art Kagel)

A few things to note about the version 11 servers.

1. Upon reaching 75% full a checkpoint will start. This checkpoint

will not block users, until a higher limit is reached which is

based on the number of users currently on the system and the

number of pages remaining in the physical log. Once

this second limit is reach the checkpoint blocks all users

modifying the database, while it is completing its current

checkpoint.

2. If the physical log becomes full, it will allocate a temporary phys=
ical

log in the file system ("plog_extend"), which it will immediately
remove

when done. This is generally not required (because of the

blocking step of #1 above), but can happen in rare cases.

It short, sizing the physical log bigger will improve performance

and reduce interruptions to users.

John F. Miller III
STSM, Embedability Architect
miller3@us.ibm.com
503-578-5645
IBM Informix Dynamic Server (IDS)

ids-bounces@iiug.org wrote on 11/29/2010 10:07:01 AM:

> [image removed]
>
> Re: WARNING! Physical Log size 140000 is too s.... [22085]
>
> Art Kagel
>
> to:
>
> ids
>
> 11/29/2010 10:07 AM
>
> Sent by:
>
> ids-bounces@iiug.org
>
> Please respond to ids
>
> Increase it to at least 187520 and see what happens. Honestly, if you=
run

> onstat -F shortly before a checkpoint during peak load and the physic=
al
log
> usage is less than 60% you can probably ignore it. The recommendation=
is
to
> prevent the physical log from becoming over 75% full and triggering a=
n
early
> checkpoint. If that happens and the physical log fills to 100% before=
the

> checkpoint completes there is a brief window during which data loss c=
ould

> occur if the server crashes immediately thereafter.
>
> Art
>
> Art S. Kagel
> Advanced DataTools (www.advancedatatools.com)
> IIUG Board of Directors (art@iiug.org)
> Blog: http://informix-myview.blogspot.com/
>
> Disclaimer: Please keep in mind that my own opinions are my own opini=
ons
and
> do not reflect on my employer, Advanced DataTools, the IIUG, nor any
other
> organization with which I am associated either explicitly, implicitly=
, or
by
> inference. Neither do those opinions reflect those of other individua=
ls
> affiliated with any entity with which I am affiliated nor those of th=
e
> entities themselves.
>
> On Mon, Nov 29, 2010 at 9:56 AM, Muthana.AL-.... <
> Muthana.AL-Temimi@tu-harburg.hamburg.de> wrote:
>
> > Hi Art,
> >
> > I saw that and it was 586 Concurrent and when multiple it with 160.=
I
get
> > 93760
> > But i setup at 140000.
> >
> > Then the question here: why should i increase it or shall i decreas=
e
it. :)
> >
> > Regards,
> > Muthana
> >
> > -----Urspr=FCngliche Nachricht-----
> > Von: ids-bounces@iiug.org [mailto:ids-bounces@iiug.org] Im Auftrag =
von
Art
> > Kagel
> > Gesendet: Montag, 29. November 2010 14:10
> > An: ids@iiug.org
> > Betreff: Re: WARNING! Physical Log size 140000 is too s.... [22078]=

> >
> > Do what the warning suggests, increase the size of the physical log=
!
You
> > can
> > start with the estimation method suggested: run onstat -u and see w=
hat
the
> > maximum concurrent connections were (listed at the bottom of the
report)
> > and
> > multiply that by 160.
> >
> > Art
> >
> > Art S. Kagel
> > Advanced DataTools (www.advancedatatools.com) IIUG Board of Directo=
rs
> > (art@iiug.org)
> > Blog: http://informix-myview.blogspot.com/
> >
> > Disclaimer: Please keep in mind that my own opinions are my own
opinions
> > and
> > do not reflect on my employer, Advanced DataTools, the IIUG, nor an=
y
other
> > organization with which I am associated either explicitly, implicit=
ly,
or
> > by
> > inference. Neither do those opinions reflect those of other individ=
uals

> > affiliated with any entity with which I am affiliated nor those of =
the
> > entities themselves.
> >
> > On Mon, Nov 29, 2010 at 4:37 AM, Muthana.AL-.... <
> > Muthana.AL-Temimi@tu-harburg.hamburg.de> wrote:
> >
> > > Dear Sir,
> > >
> > > I have got the following Warning from Primary:
> > >
> > > WARNING! Physical Log size 140000 is too small.
> > >
> > > Physical Log overflows may occur during peak activity.
> > >
> > > Recommended minimum Physical Log size is 160 times maximum
> > >
> > > concurrent user threads.
> > >
> > > Any help will be welcome
> > >
> > > Regards,
> > >
> > > Muthana AL-Temimi
> > >
> > > M.Sc. Informations- und Kommunikations-Systeme
> > >
> > > Technische Universitaet Hamburg Harburg
> > >
> > > -Rechenzentrum-
> > >
> > > Schwarzenbergstr. 95 (E)
> > >
> > > D-21073 Hamburg
> > >
> > > Tel.: +49.40.42878.2338
> > >
> > > Fax.: +49.40.42793.5160
> > >
> > > E-Mail: m.al@tu-harburg.de
> > >
> > > http://www.tu-harburg.de/rzt
> > >
> > >
> > >
> > >
> >
> >
> >
>
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********

> > > Forum Note: Use "Reply" to post a response in the discussion foru=
m.
> > >
> > >
> >
> > --485b393ab8657351d1049630ca7f
> >
> >
> >
> >
>
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********

> > Forum Note: Use "Reply" to post a response in the discussion forum.=

> >
> >
> >
> >
>
***********************************************************************=
********

> > Forum Note: Use "Reply" to post a response in the discussion forum.=

> >
> >
>
> --001636d34e5c1ae785049634f07a
>
>
>
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>=

Messages In This Thread

• WARNING! Physical Log size 140000 is too small.
  Muthana.AL-Temimi@tu-harburg.hamburg.de -- Monday, 29 November 2010, at 4:37 a.m.
  • Re: WARNING! Physical Log size 140000 is too small
    Art Kagel -- Monday, 29 November 2010, at 8:10 a.m.
    • AW: WARNING! Physical Log size 140000 is too s....
      Muthana.AL-Temimi@tu-harburg.hamburg.de -- Monday, 29 November 2010, at 9:56 a.m.
      • Re: WARNING! Physical Log size 140000 is too s....
        Art Kagel -- Monday, 29 November 2010, at 1:07 p.m.
        • Re: WARNING! Physical Log size 140000 is too s....
          John Miller iii -- Monday, 29 November 2010, at 3:19 p.m.

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