IDS Forum

Re: "Onmode -F " hangs engine

Posted By: Robert Seifert
Date: Wednesday, 19 January 2005, at 11:08 a.m.

In Response To: Re: "Onmode -F " hangs engine (Konstantin Kaduk )

Konstantin,

Per default for SAP systems the onconfig parameter SHMTOTAL is actually
set to value 0.
If you set SHMTOTAL to other value in similiar situation without any other
configuration
changes you will run into same problem but earlier than before.

If the database system requires more shared memory than is
allowed by the parameter SHMTOTAL, this should be set to a higher
value or to 0 (=unrestricted).
If, however, the shared memory that has already been used is
right on the limit of the shared memory that is made available by
the operating system, then you should consider measures to reduce
the shared memory consumption; the removal of other applications
to other machines or a storage extension.
The parameter SHMTOTAL should only be set to a value not equal to
0 if the available shared memory has to be shared online with
other applications.

For SAP systems SAP note 38307 might be helpful...

See below what I wrote to Yuri in the meantime:

Dear Yury,

Currently used 7.31.TD1X2 is quite old. The problem sounds like product
defect IBM Informix PTS 149742 which is fixed in IDS releases >=
7.31.TD2.

149742 ONMODE -F CAN HANG SERVER,...

For SAP system you should upgrade to 7.31.TD2X7 in minimum,
alternatively to latest available release 7.31.TD6 according SAP note
156549.

For large SHM configurations you may consider IDS release notes and SAP
recommendations as well. See also SAP note 41360.

If the problem still persists please open a SAP case. Please see SAP
note 113047 for needed information.
For other questions please feel free to contact me again using mail
address robert.seifert@sap.com

By the way, do you know that there exists a SAP list @ IUUG as well? You
may subscribe sapmix@iiug.org.

HTH

Best regards,

Robert




Robert Seifert
_________________________________________________________________
IBM Deutschland GmbH, Data Management Solutions, Software,
Informix Products, Advanced Support

Elite VAR support engineer
Development Support for IBM Informix Products on-site @ SAP
c/o SAP AG, -TechDev05-,Neurottstrasse 16, D-69190 Walldorf, Germany

Phone +49-6227-7-45713, Fax +49-6227-7-47147
mailto:robert.seifert@de.ibm.com or mailto:robert.seifert@sap.com
http://www.ibm.com/software/data/informix




"Konstantin ...."
<cvk@pbcards.dp.u
a> To
Sent by: ids@iiug.org
forum.subscriber@ cc
iiug.org
Subject
Re: "Onmode -F " hangs engine
19.01.2005 11:24 [4043]










Hi.

Given problem can take place when
sesions which allocate a lot of memory have being worked a long time.
Perhaps they do a hard DSS queries.
Can you drop and restart this connections from time to time.
onmode -F don't release memory while a sesions which use that memory
isn't terminated.

You also can set SHMTOTAL parameter on the onconfig.
In this case all sessions which need for additional memory will be rolled
back
when server already have took SHMTOTAL amount of memory.
Server will be work, but some transactions will be roolled back by server.

Best regards, Konstantin.

p.s. I'm from Dnipropetrovsk too.

----- Original Message -----
From: "Yury Borinsky" <bor@gc.dnepr.energy.gov.ua>
To: <ids@iiug.org>
Sent: Wednesday, January 19, 2005 10:35 AM
Subject: "Onmode -F " hangs engine [4042]


> Hello for all.
> Sorry for my English.
>
> We have SAP R/3 4.6C on Informix 7.31.TD1X2 (W2K).
> Engine eats too mach memory for 2-3 weeks and system began swapping.
> I read somewhere about "onmode -F". And I had shedule this command at
> every
> 4 hours.
> This works fine on NT 4.0, but since upgrade to W2K, we sometimes has a
> big
> problem:
> "onmode -F" is standstill for very large time (more than 30 minutes).
> After
> this,
> oninit consumpt 50% CPU time, and Informix does not respond to any
> connections.
> Even, I can't stop engine with "onmode -yuk".
> I must to reboot the system. This problem appear only 3 times for a year,
> when engine
> has a peak of memory consumption (more than 1 GB).
>
> This is some parameters of our onconfig:
> RESIDENT 0 # Forced residency flag (Yes = 1,
> No
> = 0)
> MULTIPROCESSOR 1 # 0 for single-processor, 1 for
> multi-processor
> NUMCPUVPS 2 # Number of user (cpu) vps
> SINGLE_CPU_VP 0 # If non-zero, limit number of cpu vps to
> one
> BUFFERS 100000 # Maximum number of shared buffers
> NUMAIOVPS 1 # Number of IO vps
> SHMBASE 0xC000000 # Shared memory base address
> SHMVIRTSIZE 327680 # initial virtual shared memory segment
> size
> SHMADD 32768 # Size of new shared memory segments
> (Kbytes)
> SHMTOTAL 0 # Total shared memory (Kbytes).
> 0=>unlimited
>
> Has anybody the same situation in the past?
> Who know what is the problem, please answer.
>
> With Best Regards, Yury Borinsky
> Basis Administrator and DBA of JSC "Dneproenergo" (Ukrane)
>
>
>
>
>
>

Messages In This Thread

• "Onmode -F " hangs engine
  Yury Borinsky -- Wednesday, 19 January 2005, at 3:35 a.m.
  • Re: "Onmode -F " hangs engine
    Konstantin Kaduk -- Wednesday, 19 January 2005, at 5:24 a.m.
    • RE: "Onmode -F " hangs engine
      Sebastian, Norma J. -- Wednesday, 19 January 2005, at 10:12 a.m.
    • Re: "Onmode -F " hangs engine
      Robert Seifert -- Wednesday, 19 January 2005, at 11:08 a.m.

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