ONMODE -F _ IS SAFE ?

HI MASTERS: THE USE PERIODICALLY OF (ONMODE -F) IS SAFE ?? IBM IDS 9.40.FC4W4 ON HPUX 11.11 I RUNNING A SHELL FOR EACH HOUR TO FREE THE MEMORY OF DB I HAD 5 OFF-LINE OF THE DB ON LAST WEEK I SUSPECT OF THE (ONMODE -F) COMMAND WHAT DO YOU ADVICE ??? THANKS Juan Valeriano Villegas DBA /informix> egrep "Assert Failed| 2006" was_shm.log Fri Aug 18 00:00:07 2006 15:55:42 Assert Failed: No Exception Handler Fri Aug 18 16:44:07 2006 16:52:23 Assert Failed: Memory free block header corruption detected in mt_shm_malloc_segid 5 16:53:20 Assert Failed: Memory block header corruption detected in mt_shm_free 2 16:57:41 Assert Failed: No Exception Handler Fri Aug 18 16:59:16 2006 17:13:39 Assert Failed: Memory free block header corruption detected in mt_shm_malloc_segid 5 17:14:12 Assert Failed: Memory block header corruption detected in mt_shm_free 1 17:14:59 Assert Failed: No Exception Handler 17:15:01 Assert Failed: Memory block header corruption detected in mt_shm_free 2 Fri Aug 18 17:27:28 2006 Sat Aug 19 00:00:01 2006 Sun Aug 20 10:58:50 2006 Mon Aug 21 00:02:14 2006 09:34:17 Assert Failed: Memory free block header corruption detected in mt_shm_malloc_segid 5 09:35:47 Assert Failed: Memory block header corruption detected in mt_shm_free 2 09:40:53 Assert Failed: Exception Caught. Type: MT_EX_OS, Context: mem 09:48:43 Assert Failed: No Exception Handler Mon Aug 21 10:14:58 2006 12:52:29 Assert Failed: Memory free block header corruption detected in mt_shm_malloc_segid 5 12:52:44 Assert Failed: No Exception Handler Mon Aug 21 13:00:11 2006

Hi Juan - I've never seen onmode -F take informix offline and it's always been safe, but not very effective. The engine will manage buffers appropriately without onmode -F. onmode -F will theorectically allow an additional virtual segment to be dropped if all the buffers in the segment can be freed. However, that will not happen in most environments. Check your message log to see if there are any odd messages occuring when Informix goes offline. On Aug 21, 2006, at 6:22 PM, Valeriano Villegas Juan wrote: > > HI MASTERS: > > THE USE PERIODICALLY OF (ONMODE -F) IS SAFE ?? > > IBM IDS 9.40.FC4W4 ON HPUX 11.11 > > I RUNNING A SHELL FOR EACH HOUR TO FREE THE MEMORY OF DB > > I HAD 5 OFF-LINE OF THE DB ON LAST WEEK > > I SUSPECT OF THE (ONMODE -F) COMMAND > > WHAT DO YOU ADVICE ??? > > THANKS > > Juan Valeriano Villegas > DBA > > /informix> egrep "Assert Failed| 2006" was_shm.log > Fri Aug 18 00:00:07 2006 > 15:55:42 Assert Failed: No Exception Handler > Fri Aug 18 16:44:07 2006 > 16:52:23 Assert Failed: Memory free block header corruption > detected in > mt_shm_malloc_segid 5 > 16:53:20 Assert Failed: Memory block header corruption detected in > mt_shm_free > 2 > 16:57:41 Assert Failed: No Exception Handler > Fri Aug 18 16:59:16 2006 > 17:13:39 Assert Failed: Memory free block header corruption > detected in > mt_shm_malloc_segid 5 > 17:14:12 Assert Failed: Memory block header corruption detected in > mt_shm_free 1 > 17:14:59 Assert Failed: No Exception Handler > 17:15:01 Assert Failed: Memory block header corruption detected in > mt_shm_free 2 > Fri Aug 18 17:27:28 2006 > Sat Aug 19 00:00:01 2006 > Sun Aug 20 10:58:50 2006 > Mon Aug 21 00:02:14 2006 > 09:34:17 Assert Failed: Memory free block header corruption > detected in > mt_shm_malloc_segid 5 > 09:35:47 Assert Failed: Memory block header corruption detected in > mt_shm_free 2 > 09:40:53 Assert Failed: Exception Caught. Type: MT_EX_OS, Context: mem > 09:48:43 Assert Failed: No Exception Handler > Mon Aug 21 10:14:58 2006 > 12:52:29 Assert Failed: Memory free block header corruption > detected in > mt_shm_malloc_segid 5 > 12:52:44 Assert Failed: No Exception Handler > Mon Aug 21 13:00:11 2006 > > > ********************************************************************** > ********* > Forum Note: Use "Reply" to post a response in the discussion forum. >

Juan, I have seen onmode -F coincide with an engine panicking on a memory corruption and going off-line; I would not want to categorically state that the onmode -F caused the corruption of the memory block(s)... Although I did get the same sort of errors as you have included. I will state that it is not everytime that it is run, and I don't run it often enough to be able to give you a %age risk assessment. I run both HPUX/11.00 and HPUX/11.11 I do not recall which system my occurance was on seems quite likely that it was the 11.11 like your incident. I've never however had a need to run it as frequently as you do, it is a tremendously rare occurance and only required when reports (or more accurately the authors of reports) cause tremendously large union (200+ table) seqscan queries, upon failing which they ultimately do I need to clean some of the memory segments manually. I also have a recollection of an advisory, very very many years ago for older versions of IDS that there was a risk of a failure with onmode -F; but I could be completely wrong... my memory is as volatile as my machines ;) Cliff. -----Original Message----- From: ids-bounces@iiug.org [mailto:ids-bounces@iiug.org] On Behalf Of Christine Normile Sent: Tuesday, 22 August 2006 11:02 To: ids@iiug.org Subject: Re: ONMODE -F _ IS SAFE ? [7319] Hi Juan - I've never seen onmode -F take informix offline and it's always been safe, but not very effective. The engine will manage buffers appropriately without onmode -F. onmode -F will theorectically allow an additional virtual segment to be dropped if all the buffers in the segment can be freed. However, that will not happen in most environments. Check your message log to see if there are any odd messages occuring when Informix goes offline. On Aug 21, 2006, at 6:22 PM, Valeriano Villegas Juan wrote: > > HI MASTERS: > > THE USE PERIODICALLY OF (ONMODE -F) IS SAFE ?? > > IBM IDS 9.40.FC4W4 ON HPUX 11.11 > > I RUNNING A SHELL FOR EACH HOUR TO FREE THE MEMORY OF DB > > I HAD 5 OFF-LINE OF THE DB ON LAST WEEK > > I SUSPECT OF THE (ONMODE -F) COMMAND > > WHAT DO YOU ADVICE ??? > > THANKS > > Juan Valeriano Villegas > DBA > ************************************************************************ ******* Forum Note: Use "Reply" to post a response in the discussion forum. ******************************************************************* Everything about this email and its attachments, including potentially confidential components, is only for the eyes and ears of the persons to whom it has been addressed (i.e. the persons whose names appear in the "To" section of the email; however, those listed in sections "CC" and "BCC" may also consider themselves included in the group whose eyes and ears this email is for.). In the event that no physical, emotional or spiritual resemblance can be made between you and the intended recipients, you have been mistakenly or deliberately omitted from the email, someone has given it to you, or you have nicked it. If you're not supposed to have access to this email, please delete it, destroy it and deprive others from it. Oh, and let us know when you are done. *******************************************************************

Valeriano, why don´t you enlarge your initial virtual shared memory segment size (SHMVIRTSIZE), if it's increasing frequently then you're wasting time and performance, because many adicional virtual shared memory segments decrease the performance. Celso Coimbra ClearTech Ltda "Unlock your revenue" Tel: (019) 2104-4509 E-mail: ccoimbra@cleartech.com.br -----Mensagem original----- De: ids-bounces@iiug.org [mailto:ids-bounces@iiug.org]Em nome de Valeriano Villegas Juan Enviada em: segunda-feira, 21 de agosto de 2006 20:23 Para: ids@iiug.org Assunto: ONMODE -F _ IS SAFE ? [7318] HI MASTERS: THE USE PERIODICALLY OF (ONMODE -F) IS SAFE ?? IBM IDS 9.40.FC4W4 ON HPUX 11.11 I RUNNING A SHELL FOR EACH HOUR TO FREE THE MEMORY OF DB I HAD 5 OFF-LINE OF THE DB ON LAST WEEK I SUSPECT OF THE (ONMODE -F) COMMAND WHAT DO YOU ADVICE ??? THANKS Juan Valeriano Villegas DBA /informix> egrep "Assert Failed| 2006" was_shm.log Fri Aug 18 00:00:07 2006 15:55:42 Assert Failed: No Exception Handler Fri Aug 18 16:44:07 2006 16:52:23 Assert Failed: Memory free block header corruption detected in mt_shm_malloc_segid 5 16:53:20 Assert Failed: Memory block header corruption detected in mt_shm_free 2 16:57:41 Assert Failed: No Exception Handler Fri Aug 18 16:59:16 2006 17:13:39 Assert Failed: Memory free block header corruption detected in mt_shm_malloc_segid 5 17:14:12 Assert Failed: Memory block header corruption detected in mt_shm_free 1 17:14:59 Assert Failed: No Exception Handler 17:15:01 Assert Failed: Memory block header corruption detected in mt_shm_free 2 Fri Aug 18 17:27:28 2006 Sat Aug 19 00:00:01 2006 Sun Aug 20 10:58:50 2006 Mon Aug 21 00:02:14 2006 09:34:17 Assert Failed: Memory free block header corruption detected in mt_shm_malloc_segid 5 09:35:47 Assert Failed: Memory block header corruption detected in mt_shm_free 2 09:40:53 Assert Failed: Exception Caught. Type: MT_EX_OS, Context: mem 09:48:43 Assert Failed: No Exception Handler Mon Aug 21 10:14:58 2006 12:52:29 Assert Failed: Memory free block header corruption detected in mt_shm_malloc_segid 5 12:52:44 Assert Failed: No Exception Handler Mon Aug 21 13:00:11 2006 ******************************************************************************* Forum Note: Use "Reply" to post a response in the discussion forum.

I had onmode -F take down a IDS10 engine...but only had it happen once...needless to say shy of it now. -- Sam Gentsch office (334)768-7039 cell (706)289-6710 -----Original Message----- From: ids-bounces@iiug.org [mailto:ids-bounces@iiug.org] On Behalf Of Valeriano Villegas Juan Sent: Monday, August 21, 2006 7:23 PM To: ids@iiug.org Subject: ONMODE -F _ IS SAFE ? [7318] HI MASTERS: THE USE PERIODICALLY OF (ONMODE -F) IS SAFE ?? IBM IDS 9.40.FC4W4 ON HPUX 11.11 I RUNNING A SHELL FOR EACH HOUR TO FREE THE MEMORY OF DB I HAD 5 OFF-LINE OF THE DB ON LAST WEEK I SUSPECT OF THE (ONMODE -F) COMMAND WHAT DO YOU ADVICE ??? THANKS Juan Valeriano Villegas DBA /informix> egrep "Assert Failed| 2006" was_shm.log Fri Aug 18 00:00:07 2006 15:55:42 Assert Failed: No Exception Handler Fri Aug 18 16:44:07 2006 16:52:23 Assert Failed: Memory free block header corruption detected in mt_shm_malloc_segid 5 16:53:20 Assert Failed: Memory block header corruption detected in mt_shm_free 2 16:57:41 Assert Failed: No Exception Handler Fri Aug 18 16:59:16 2006 17:13:39 Assert Failed: Memory free block header corruption detected in mt_shm_malloc_segid 5 17:14:12 Assert Failed: Memory block header corruption detected in mt_shm_free 1 17:14:59 Assert Failed: No Exception Handler 17:15:01 Assert Failed: Memory block header corruption detected in mt_shm_free 2 Fri Aug 18 17:27:28 2006 Sat Aug 19 00:00:01 2006 Sun Aug 20 10:58:50 2006 Mon Aug 21 00:02:14 2006 09:34:17 Assert Failed: Memory free block header corruption detected in mt_shm_malloc_segid 5 09:35:47 Assert Failed: Memory block header corruption detected in mt_shm_free 2 09:40:53 Assert Failed: Exception Caught. Type: MT_EX_OS, Context: mem 09:48:43 Assert Failed: No Exception Handler Mon Aug 21 10:14:58 2006 12:52:29 Assert Failed: Memory free block header corruption detected in mt_shm_malloc_segid 5 12:52:44 Assert Failed: No Exception Handler Mon Aug 21 13:00:11 2006 ************************************************************************ ******* Forum Note: Use "Reply" to post a response in the discussion forum.

We are using an older version of Inf 7.31.4 and have the onmode -F run each morning at 6:00 to free memory as needed. We have yet to have this cause a failure. 3 years and running on the Solaris platform Yes I know it is time to move on .... John Caron USBC-MA 508-770-8957 "Gentsch, Sam" <sgentsch@interca ll.com> To Sent by: ids@iiug.org ids-bounces@iiug. cc org Subject RE: ONMODE -F _ IS SAFE ? [7340] 08/24/2006 03:12 PM Please respond to ids@iiug.org I had onmode -F take down a IDS10 engine...but only had it happen once...needless to say shy of it now. -- Sam Gentsch office (334)768-7039 cell (706)289-6710 -----Original Message----- From: ids-bounces@iiug.org [mailto:ids-bounces@iiug.org] On Behalf Of Valeriano Villegas Juan Sent: Monday, August 21, 2006 7:23 PM To: ids@iiug.org Subject: ONMODE -F _ IS SAFE ? [7318] HI MASTERS: THE USE PERIODICALLY OF (ONMODE -F) IS SAFE ?? IBM IDS 9.40.FC4W4 ON HPUX 11.11 I RUNNING A SHELL FOR EACH HOUR TO FREE THE MEMORY OF DB I HAD 5 OFF-LINE OF THE DB ON LAST WEEK I SUSPECT OF THE (ONMODE -F) COMMAND WHAT DO YOU ADVICE ??? THANKS Juan Valeriano Villegas DBA /informix> egrep "Assert Failed| 2006" was_shm.log Fri Aug 18 00:00:07 2006 15:55:42 Assert Failed: No Exception Handler Fri Aug 18 16:44:07 2006 16:52:23 Assert Failed: Memory free block header corruption detected in mt_shm_malloc_segid 5 16:53:20 Assert Failed: Memory block header corruption detected in mt_shm_free 2 16:57:41 Assert Failed: No Exception Handler Fri Aug 18 16:59:16 2006 17:13:39 Assert Failed: Memory free block header corruption detected in mt_shm_malloc_segid 5 17:14:12 Assert Failed: Memory block header corruption detected in mt_shm_free 1 17:14:59 Assert Failed: No Exception Handler 17:15:01 Assert Failed: Memory block header corruption detected in mt_shm_free 2 Fri Aug 18 17:27:28 2006 Sat Aug 19 00:00:01 2006 Sun Aug 20 10:58:50 2006 Mon Aug 21 00:02:14 2006 09:34:17 Assert Failed: Memory free block header corruption detected in mt_shm_malloc_segid 5 09:35:47 Assert Failed: Memory block header corruption detected in mt_shm_free 2 09:40:53 Assert Failed: Exception Caught. Type: MT_EX_OS, Context: mem 09:48:43 Assert Failed: No Exception Handler Mon Aug 21 10:14:58 2006 12:52:29 Assert Failed: Memory free block header corruption detected in mt_shm_malloc_segid 5 12:52:44 Assert Failed: No Exception Handler Mon Aug 21 13:00:11 2006 ************************************************************************ ******* Forum Note: Use "Reply" to post a response in the discussion forum. ******************************************************************************* Forum Note: Use "Reply" to post a response in the discussion forum.

I've seen crontab'd onmode -F take the engine down in most versions Cheers Paul Paul Watson Tel: +44 1414161772 Mob: +44 7818003457 Web: www.oninit.com GO FURTHER with DB2 GET THERE FASTER with Informix. Attend the IDUG 2006 European Conference. Vienna, Austria. 2-6 October 2006 Visit http://www.iiug.org/conf for more information. -----Original Message----- From: ids-bounces@iiug.org [mailto:ids-bounces@iiug.org] On Behalf Of Gentsch, Sam Sent: 24 August 2006 14:13 To: ids@iiug.org Subject: RE: ONMODE -F _ IS SAFE ? [7340] I had onmode -F take down a IDS10 engine...but only had it happen once...needless to say shy of it now. -- Sam Gentsch office (334)768-7039 cell (706)289-6710 -----Original Message----- From: ids-bounces@iiug.org [mailto:ids-bounces@iiug.org] On Behalf Of Valeriano Villegas Juan Sent: Monday, August 21, 2006 7:23 PM To: ids@iiug.org Subject: ONMODE -F _ IS SAFE ? [7318] HI MASTERS: THE USE PERIODICALLY OF (ONMODE -F) IS SAFE ?? IBM IDS 9.40.FC4W4 ON HPUX 11.11 I RUNNING A SHELL FOR EACH HOUR TO FREE THE MEMORY OF DB I HAD 5 OFF-LINE OF THE DB ON LAST WEEK I SUSPECT OF THE (ONMODE -F) COMMAND WHAT DO YOU ADVICE ??? THANKS Juan Valeriano Villegas DBA /informix> egrep "Assert Failed| 2006" was_shm.log Fri Aug 18 00:00:07 2006 15:55:42 Assert Failed: No Exception Handler Fri Aug 18 16:44:07 2006 16:52:23 Assert Failed: Memory free block header corruption detected in mt_shm_malloc_segid 5 16:53:20 Assert Failed: Memory block header corruption detected in mt_shm_free 2 16:57:41 Assert Failed: No Exception Handler Fri Aug 18 16:59:16 2006 17:13:39 Assert Failed: Memory free block header corruption detected in mt_shm_malloc_segid 5 17:14:12 Assert Failed: Memory block header corruption detected in mt_shm_free 1 17:14:59 Assert Failed: No Exception Handler 17:15:01 Assert Failed: Memory block header corruption detected in mt_shm_free 2 Fri Aug 18 17:27:28 2006 Sat Aug 19 00:00:01 2006 Sun Aug 20 10:58:50 2006 Mon Aug 21 00:02:14 2006 09:34:17 Assert Failed: Memory free block header corruption detected in mt_shm_malloc_segid 5 09:35:47 Assert Failed: Memory block header corruption detected in mt_shm_free 2 09:40:53 Assert Failed: Exception Caught. Type: MT_EX_OS, Context: mem 09:48:43 Assert Failed: No Exception Handler Mon Aug 21 10:14:58 2006 12:52:29 Assert Failed: Memory free block header corruption detected in mt_shm_malloc_segid 5 12:52:44 Assert Failed: No Exception Handler Mon Aug 21 13:00:11 2006 ************************************************************************ ******* Forum Note: Use "Reply" to post a response in the discussion forum. **************************************************************************** *** Forum Note: Use "Reply" to post a response in the discussion forum.