Advise needed - BUFFERS increased?

Hello, I need to hear some other opinion about the problem we are having with the Informix performance and the change I am planning to do. I have calculated the BR (buffer ratio) and it looks not so bad =7.2%, the BTR = 8.1. I had increased the LRUS to 120 a while ago and it the BR ususaly is fine since. The question was about the number of BUFFERS=60000 - whether it is a bottlneck or not. My only concern is that the Read cache is > 95% and the checkpoints are 0-1 sec. According to Informix recommendation - BUFFERS should take about 20-25% of the physical memory. We have 1.5 Gb physical memory, 20% from it = 175 000 Kb. So we are quite under what is recommended. My question is in case the checkpoints are OK and the Read cache is OK as well, should I increase the number of the BUFFERS anyway? I noticed that there si some paging on the Unix side as well and some of the values exceed a lot of what Caldera recommends, vflt/s should be up to 50 and in our case sometimes (usualy when there si a slowdown) it is very high. We have opened a case with Caldera and are waiting for them get back to us if there si any Unix kernel parameters tuned. Here are some outputs: informix@vaprp1> sar -p 5 5 UnixWare vaprp1 5 7.1.1 i386 02/06/03 10:18:57 atch/s atfree/s atmiss/s pgin/s ppgin/s pflt/s vflt/s slock/s 10:19:02 577.26 46.59 19.90 12.54 26.09 161.38 3237.51 0.00 10:19:07 642.43 41.83 16.73 13.15 13.15 118.13 1160.16 0.00 10:19:12 415.34 33.07 15.74 7.17 8.37 121.12 2102.99 0.00 10:19:17 489.64 79.88 41.24 28.88 28.88 184.26 3093.03 0.00 10:19:22 279.28 33.86 16.53 13.15 13.15 76.29 2037.45 0.00 Average 480.76 47.04 22.03 14.98 17.92 132.23 2325.75 0.00 informix@vaprp1> sar -g 5 5 UnixWare vaprp1 5 7.1.1 i386 02/06/03 10:26:01 pgout/s ppgout/s vfree/s pfree/s vscan/s 10:26:06 0.00 0.00 0.00 0.00 0.00 10:26:11 0.00 0.00 0.00 0.00 0.00 10:26:16 0.00 0.00 0.00 0.00 0.00 10:26:21 0.00 0.00 0.00 0.00 0.00 10:26:26 0.00 0.00 0.00 0.00 0.00 Average 0.00 0.00 0.00 0.00 0.00 informix@vaprp1> onstat -p Informix Dynamic Server Version 7.30.UC10 -- On-Line -- Up 10 days 00:22:11 -- 385408 Kbytes Profile dskreads pagreads bufreads Êched dskwrits pagwrits bufwrits Êched 44696909 10248696 1167888021 96.17 7258168 6603468 107632833 93.26 isamtot open start read write rewrite delete commit rollbk 3863981449 59800856 251343347 2931610071 33553037 5332563 8340525 2942299 61 gp_read gp_write gp_rewrt gp_del gp_alloc gp_free gp_curs 0 0 0 0 0 0 0 ovlock ovuserthread ovbuff usercpu syscpu numckpts flushes 0 0 0 231653.57 15413.57 2994 5988 bufwaits lokwaits lockreqs deadlks dltouts ckpwaits compress seqscans 8494035 7352 1324200902 0 0 6624 891354 14479158 ixda-RA idx-RA da-RA RA-pgsused lchwaits 13176595 182578 11571397 24914619 35550 Message Log File: /usr2/informix/online.log 09:21:55 Checkpoint Completed: duration was 0 seconds. 09:26:55 Checkpoint Completed: duration was 0 seconds. 09:31:55 Checkpoint Completed: duration was 0 seconds. 09:36:55 Checkpoint Completed: duration was 0 seconds. 09:38:09 Logical Log 192586 Complete. 09:38:11 Logical Log 192586 - Backup Started 09:38:30 Logical Log 192586 - Backup Completed 09:41:55 Checkpoint Completed: duration was 0 seconds. 09:46:55 Checkpoint Completed: duration was 0 seconds. 09:51:55 Checkpoint Completed: duration was 0 seconds. 09:56:55 Checkpoint Completed: duration was 0 seconds. 10:01:56 Checkpoint Completed: duration was 0 seconds. 10:06:56 Checkpoint Completed: duration was 0 seconds. 10:11:48 Logical Log 192587 Complete. 10:11:51 Logical Log 192587 - Backup Started 10:11:56 Checkpoint Completed: duration was 1 seconds. 10:12:01 Logical Log 192587 - Backup Completed 10:16:57 Checkpoint Completed: duration was 1 seconds. 10:21:58 Checkpoint Completed: duration was 0 seconds. 10:26:58 Checkpoint Completed: duration was 1 seconds. informix@vaprp1> onstat -P|more Informix Dynamic Server Version 7.30.UC10 -- On-Line -- Up 10 days 00:25:58 -- 385408 Kbytes partnum total btree data other resident dirty 0 1283 270 130 883 0 227 1048578 2 1 1 0 0 0 1048579 2 2 0 0 0 0 1048580 1 1 0 0 0 0 1048582 1 1 0 0 0 0 1048584 1 1 0 0 0 0 1048606 1 1 0 0 0 0 1048708 2 1 0 1 0 0 1048709 2 0 1 1 0 0 3145743 1 0 1 0 0 1 3145746 2 0 1 1 0 0 3145779 2 2 0 0 0 0 3145786 1 0 1 0 0 1 3145803 1 0 1 0 0 0 3145835 1 1 0 0 0 0 3145862 2 2 0 0 0 0 3145883 1 1 0 0 0 0 3145923 5 0 5 0 0 0 3145985 2 0 2 0 0 2 Thanks, Milena __________________________________________________ Do you Yahoo!? Yahoo! Mail Plus - Powerful. Affordable. Sign up now. http://mailplus.yahoo.com

I don't think that a read cache rate less than 99% is acceptable. I'd add more buffers. -- Bye now, Obnoxio "C'est pas parce qu'on n'a rien à dire qu'il faut fermer sa gueule" - Coluche >From: "Milena Ilieva " <milena_ilieva@yahoo.com> >To: ids@iiug.org >Subject: Advise needed - BUFFERS increased? [278] Date: Thu, 6 Feb 2003 >14:30:58 -0500 (EST) > >Hello, > >I need to hear some other opinion about the problem we >are having with the Informix performance and the >change I am planning to do. > >I have calculated the BR (buffer ratio) and it looks >not so bad =7.2%, the BTR = 8.1. >I had increased the LRUS to 120 a while ago and it the >BR ususaly is fine since. The question was about the >number of BUFFERS=60000 - whether it is a bottlneck or >not. My only concern is that the Read cache is > 95% >and the checkpoints are 0-1 sec. According to Informix >recommendation - BUFFERS should take about 20-25% of >the physical memory. We have 1.5 Gb physical memory, >20% from it = 175 000 Kb. So we are quite under what >is recommended. >My question is in case the checkpoints are OK and the >Read cache is OK as well, should I increase the number >of the BUFFERS anyway? > >I noticed that there si some paging on the Unix side >as well and some of the values exceed a lot of what >Caldera recommends, vflt/s should be up to 50 and in >our case sometimes (usualy when there si a slowdown) >it is very high. We have opened a case with Caldera >and are waiting for them get back to us if there si >any Unix kernel parameters tuned. >Here are some outputs: >informix@vaprp1> sar -p 5 5 > >UnixWare vaprp1 5 7.1.1 i386 02/06/03 > >10:18:57 atch/s atfree/s atmiss/s pgin/s ppgin/s >pflt/s vflt/s slock/s >10:19:02 577.26 46.59 19.90 12.54 26.09 >161.38 3237.51 0.00 >10:19:07 642.43 41.83 16.73 13.15 13.15 >118.13 1160.16 0.00 >10:19:12 415.34 33.07 15.74 7.17 8.37 >121.12 2102.99 0.00 >10:19:17 489.64 79.88 41.24 28.88 28.88 >184.26 3093.03 0.00 >10:19:22 279.28 33.86 16.53 13.15 13.15 > 76.29 2037.45 0.00 >Average 480.76 47.04 22.03 14.98 17.92 >132.23 2325.75 0.00 > > >informix@vaprp1> sar -g 5 5 > >UnixWare vaprp1 5 7.1.1 i386 02/06/03 > >10:26:01 pgout/s ppgout/s vfree/s pfree/s >vscan/s >10:26:06 0.00 0.00 0.00 0.00 >0.00 >10:26:11 0.00 0.00 0.00 0.00 >0.00 >10:26:16 0.00 0.00 0.00 0.00 >0.00 >10:26:21 0.00 0.00 0.00 0.00 >0.00 >10:26:26 0.00 0.00 0.00 0.00 >0.00 >Average 0.00 0.00 0.00 0.00 >0.00 > > >informix@vaprp1> onstat -p > >Informix Dynamic Server Version 7.30.UC10 -- On-Line >-- Up 10 days 00:22:11 -- > 385408 Kbytes > >Profile >dskreads pagreads bufreads Êched dskwrits pagwrits >bufwrits Êched >44696909 10248696 1167888021 96.17 7258168 6603468 >107632833 93.26 > >isamtot open start read write rewrite >delete commit rollbk >3863981449 59800856 251343347 2931610071 33553037 >5332563 8340525 2942299 61 > >gp_read gp_write gp_rewrt gp_del gp_alloc gp_free >gp_curs >0 0 0 0 0 0 >0 > >ovlock ovuserthread ovbuff usercpu syscpu >numckpts flushes >0 0 0 231653.57 15413.57 2994 > 5988 > >bufwaits lokwaits lockreqs deadlks dltouts ckpwaits >compress seqscans >8494035 7352 1324200902 0 0 6624 > 891354 14479158 > >ixda-RA idx-RA da-RA RA-pgsused lchwaits >13176595 182578 11571397 24914619 35550 > > >Message Log File: /usr2/informix/online.log >09:21:55 Checkpoint Completed: duration was 0 >seconds. >09:26:55 Checkpoint Completed: duration was 0 >seconds. >09:31:55 Checkpoint Completed: duration was 0 >seconds. >09:36:55 Checkpoint Completed: duration was 0 >seconds. >09:38:09 Logical Log 192586 Complete. >09:38:11 Logical Log 192586 - Backup Started >09:38:30 Logical Log 192586 - Backup Completed >09:41:55 Checkpoint Completed: duration was 0 >seconds. >09:46:55 Checkpoint Completed: duration was 0 >seconds. >09:51:55 Checkpoint Completed: duration was 0 >seconds. >09:56:55 Checkpoint Completed: duration was 0 >seconds. >10:01:56 Checkpoint Completed: duration was 0 >seconds. >10:06:56 Checkpoint Completed: duration was 0 >seconds. >10:11:48 Logical Log 192587 Complete. >10:11:51 Logical Log 192587 - Backup Started >10:11:56 Checkpoint Completed: duration was 1 >seconds. >10:12:01 Logical Log 192587 - Backup Completed >10:16:57 Checkpoint Completed: duration was 1 >seconds. >10:21:58 Checkpoint Completed: duration was 0 >seconds. >10:26:58 Checkpoint Completed: duration was 1 >seconds. > >informix@vaprp1> onstat -P|more > >Informix Dynamic Server Version 7.30.UC10 -- On-Line >-- Up 10 days 00:25:58 -- > 385408 Kbytes >partnum total btree data other resident >dirty >0 1283 270 130 883 0 >227 >1048578 2 1 1 0 0 >0 >1048579 2 2 0 0 0 >0 >1048580 1 1 0 0 0 >0 >1048582 1 1 0 0 0 >0 >1048584 1 1 0 0 0 >0 >1048606 1 1 0 0 0 >0 >1048708 2 1 0 1 0 >0 >1048709 2 0 1 1 0 >0 >3145743 1 0 1 0 0 >1 >3145746 2 0 1 1 0 >0 >3145779 2 2 0 0 0 >0 >3145786 1 0 1 0 0 >1 >3145803 1 0 1 0 0 >0 >3145835 1 1 0 0 0 >0 >3145862 2 2 0 0 0 >0 >3145883 1 1 0 0 0 >0 >3145923 5 0 5 0 0 >0 >3145985 2 0 2 0 0 >2 > >Thanks, > >Milena > > > >__________________________________________________ >Do you Yahoo!? >Yahoo! Mail Plus - Powerful. Affordable. Sign up now. >http://mailplus.yahoo.com _________________________________________________________________ Tired of spam? Get advanced junk mail protection with MSN 8. http://join.msn.com/?page=features/junkmail