CHKPTINTVL inconsistent

Posted in 2013

Topics: High Availability & Replication, Triggers, Constraints & Referential Integrity, Logging & Checkpoints, Versions, Editions & End-of-Life

MARK JALKIEWICZ — Wed, 11 Dec 2013 16:17:54 — source: IIUG Forums & Mailing Lists

11.70.FC4 AIX RTO_SERVER_RESTART 0AUTO_CKPTS 1 CKPTINTVL 300 I have noticed that on a production HDR instance the checkpoint interval is not staying true around the 300 seconds interval. It seems to switch back and forth from 300s to 900s then to 600s, with the only noticeable pattern being that the more dirty the buffers then the checkpoint will fire on the 300 second interval. RTO_SERVER_RESTART is 0. According to the online documentation CKPINTVL and RTO_SERVER_RESTART are mutually exclusive where CKPINTVL is ignored if RTO_SERVER_RESTART is set; does not mention anything about AUTO_CKPTS (set to 1) being in the mix . Is there a logical explanation ? here is a snapshot from overnite (very little activity on this instance overnite) IBM Informix Dynamic SerIBM Informix Dynamic Server Version 11.70.FC4X8 -- On-Line (Prim) -- Up 2 days 22:49:14 -- 953264 Kbytes AUTO_CKPTS=On RTO_SERVER_RESTART=Off Critical Sections Physical Log Logical Log Clock Total Flush Block # Ckpt Wait Long # Dirty Dskflu Total Avg Total Avg Interval Time Trigger LSN Time Time Time Waits Time Time Time Buffers /Sec Pages /Sec Pages /Sec 51840 04:40:06 CKPTINTVL 1462:0x640018 0.0 0.0 0.0 0 0.00 0.0 0.0 1 1 2 0 2 0 51841 04:55:06 CKPTINTVL 1462:0x642018 0.0 0.0 0.0 0 0.00 0.0 0.0 1 1 2 0 2 0 51842 05:00:06 CKPTINTVL 1462:0x64b0e8 0.0 0.0 0.0 0 0.00 0.0 0.0 13 13 13 0 9 0 51843 05:10:06 CKPTINTVL 1462:0x64d018 0.0 0.0 0.0 0 0.00 0.0 0.0 1 1 4 0 2 0 51844 05:25:06 CKPTINTVL 1462:0x64f018 0.0 0.0 0.0 0 0.00 0.0 0.0 1 1 2 0 2 0 51845 05:40:06 CKPTINTVL 1462:0x652018 0.0 0.00 0.0 0 0.00 0.0 0.0 15 15 16 0 3 0 51846 05:55:06 CKPTINTVL 1462:0x654018 0.0 0.0 0.0 0 0.00 0.0 0.0 1 1 14 0 2 0 51847 06:10:07 CKPTINTVL 1462:0x656018 0.0 0.0 0.0 0 0.00 0.0 0.0 1 1 2 0 2 0 51848 06:25:07 CKPTINTVL 1462:0x658018 0.0 0.0 0.0 0 0.00 0.0 0.0 1 1 2 0 2 0 51849 06:40:07 CKPTINTVL 1462:0x65a018 0.0 0.0 0.0 0 0.00 0.0 0.0 1 1 2 0 2 0 51850 06:55:07 CKPTINTVL 1462:0x65c018 0.0 0.0 0.0 0 0.00 0.0 0.0 1 1 2 0 2 0 51851 07:00:07 CKPTINTVL 1462:0x661018 0.0 0.00 0.0 0 0.00 0.0 0.0 34 34 34 0 5 0 51852 07:05:07 CKPTINTVL 1462:0x664348 0.0 0.0 0.0 0 0.00 0.0 0.0 8 8 23 0 3 0 51853 07:10:07 CKPTINTVL 1462:0x668018 0.0 0.00 0.0 0 0.00 0.0 0.0 22 22 25 0 4 0 51854 07:25:07 CKPTINTVL 1462:0x66a018 0.0 0.0 0.0 0 0.00 0.0 0.0 2 2 17 0 2 0 51855 07:30:07 CKPTINTVL 1462:0x6d1018 0.0 0.00 0.0 0 0.00 0.0 0.0 80 80 60 0 103 0 51856 07:40:07 CKPTINTVL 1462:0x6d3018 0.0 0.0 0.0 0 0.00 0.0 0.0 1 1 19 0 2 0 51857 07:55:07 CKPTINTVL 1462:0x6d5018 0.0 0.0 0.0 0 0.00 0.0 0.0 1 1 2 0 2 0 51858 08:05:07 CKPTINTVL 1462:0x6d8348 0.0 0.0 0.0 0 0.00 0.0 0.0 9 9 9 0 3 0 51859 08:10:07 CKPTINTVL 1462:0x6e1018 0.1 0.0 0.0 0 0.00 0.0 0.0 40 40 40 0 9 0 Max Plog Max Llog Max Dskflush Avg Dskflush Avg Dirty Blocked pages/sec pages/sec Time pages/sec pages/sec Time 427 365 2 602 0 0 Regards, Mark

↪ replying to MARK JALKIEWICZ

JACQUES RENAUT — Wed, 11 Dec 2013 16:56:35 — source: IIUG Forums & Mailing Lists

Original post: 11.70.FC4 AIX RTO_SERVER_RESTART 0AUTO_CKPTS 1 CKPTINTVL 300 I have noticed that on a production HDR instance the checkpoint interval is not staying true around the 300 seconds interval. It seems to switch back and forth from 300s to 900s then to 600s, with the only noticeable pattern being that the more dirty the buffers then the checkpoint will fire on the 300 second interval. RTO_SERVER_RESTART is 0. According to the online documentation CKPINTVL and RTO_SERVER_RESTART are mutually exclusive where CKPINTVL is ignored if RTO_SERVER_RESTART is set; does not mention anything about AUTO_CKPTS (set to 1) being in the mix . Is there a logical explanation ? here is a snapshot from overnite (very little activity on this instance overnite) IBM Informix Dynamic SerIBM Informix Dynamic Server Version 11.70.FC4X8 -- On-Line (Prim) -- Up 2 days 22:49:14 -- 953264 Kbytes AUTO_CKPTS=On RTO_SERVER_RESTART=Off Critical Sections Physical Log Logical Log Clock Total Flush Block # Ckpt Wait Long # Dirty Dskflu Total Avg Total Avg Interval Time Trigger LSN Time Time Time Waits Time Time Time Buffers /Sec Pages /Sec Pages /Sec 51840 04:40:06 CKPTINTVL 1462:0x640018 0.0 0.0 0.0 0 0.00 0.0 0.0 1 1 2 0 2 0 51841 04:55:06 CKPTINTVL 1462:0x642018 0.0 0.0 0.0 0 0.00 0.0 0.0 1 1 2 0 2 0 51842 05:00:06 CKPTINTVL 1462:0x64b0e8 0.0 0.0 0.0 0 0.00 0.0 0.0 13 13 13 0 9 0 51843 05:10:06 CKPTINTVL 1462:0x64d018 0.0 0.0 0.0 0 0.00 0.0 0.0 1 1 4 0 2 0 51844 05:25:06 CKPTINTVL 1462:0x64f018 0.0 0.0 0.0 0 0.00 0.0 0.0 1 1 2 0 2 0 51845 05:40:06 CKPTINTVL 1462:0x652018 0.0 0.00 0.0 0 0.00 0.0 0.0 15 15 16 0 3 0 51846 05:55:06 CKPTINTVL 1462:0x654018 0.0 0.0 0.0 0 0.00 0.0 0.0 1 1 14 0 2 0 51847 06:10:07 CKPTINTVL 1462:0x656018 0.0 0.0 0.0 0 0.00 0.0 0.0 1 1 2 0 2 0 51848 06:25:07 CKPTINTVL 1462:0x658018 0.0 0.0 0.0 0 0.00 0.0 0.0 1 1 2 0 2 0 51849 06:40:07 CKPTINTVL 1462:0x65a018 0.0 0.0 0.0 0 0.00 0.0 0.0 1 1 2 0 2 0 51850 06:55:07 CKPTINTVL 1462:0x65c018 0.0 0.0 0.0 0 0.00 0.0 0.0 1 1 2 0 2 0 51851 07:00:07 CKPTINTVL 1462:0x661018 0.0 0.00 0.0 0 0.00 0.0 0.0 34 34 34 0 5 0 51852 07:05:07 CKPTINTVL 1462:0x664348 0.0 0.0 0.0 0 0.00 0.0 0.0 8 8 23 0 3 0 51853 07:10:07 CKPTINTVL 1462:0x668018 0.0 0.00 0.0 0 0.00 0.0 0.0 22 22 25 0 4 0 51854 07:25:07 CKPTINTVL 1462:0x66a018 0.0 0.0 0.0 0 0.00 0.0 0.0 2 2 17 0 2 0 51855 07:30:07 CKPTINTVL 1462:0x6d1018 0.0 0.00 0.0 0 0.00 0.0 0.0 80 80 60 0 103 0 51856 07:40:07 CKPTINTVL 1462:0x6d3018 0.0 0.0 0.0 0 0.00 0.0 0.0 1 1 19 0 2 0 51857 07:55:07 CKPTINTVL 1462:0x6d5018 0.0 0.0 0.0 0 0.00 0.0 0.0 1 1 2 0 2 0 51858 08:05:07 CKPTINTVL 1462:0x6d8348 0.0 0.0 0.0 0 0.00 0.0 0.0 9 9 9 0 3 0 51859 08:10:07 CKPTINTVL 1462:0x6e1018 0.1 0.0 0.0 0 0.00 0.0 0.0 40 40 40 0 9 0 Max Plog Max Llog Max Dskflush Avg Dskflush Avg Dirty Blocked pages/sec pages/sec Time pages/sec pages/sec Time 427 365 2 602 0 0 Regards, Mark Response: The server will not checkpoint at CKPTINTVL if there was no activity (and by activity I believe it means some sort of activity that would generate log records so read activity would not trigger them), it has been like this for a long while now. Jacques Renaut IBM Informix Advanced Support APD Team

↪ replying to MARK JALKIEWICZ

Paul Watson — Wed, 11 Dec 2013 16:59:42 — source: IIUG Forums & Mailing Lists

If there is nothing to do then there is no checkpoint and no record Cheers Paul > 11.70.FC4 AIX > > RTO_SERVER_RESTART 0> AUTO_CKPTS 1 > CKPTINTVL 300> > I have noticed that on a production HDR instance the checkpoint interval > is > not staying true around the 300 seconds interval. It seems to switch back > and > forth from 300s to 900s then to 600s, with the only noticeable pattern > being > that the more dirty the buffers then the checkpoint will fire on the 300 > second interval. RTO_SERVER_RESTART is 0. According to the online > documentation CKPINTVL and RTO_SERVER_RESTART are mutually exclusive where > CKPINTVL is ignored if RTO_SERVER_RESTART is set; does not mention > anything > about AUTO_CKPTS (set to 1) being in the mix . > > Is there a logical explanation ? > > here is a snapshot from overnite (very little activity on this instance > overnite) > > IBM Informix Dynamic SerIBM Informix Dynamic Server Version 11.70.FC4X8 -- > On-Line (Prim) -- Up 2 days 22:49:14 -- 953264 Kbytes > > AUTO_CKPTS=On RTO_SERVER_RESTART=Off > > Critical Sections Physical Log Logical Log > > Clock Total Flush Block # Ckpt Wait Long # Dirty Dskflu Total Avg Total > Avg > Interval Time Trigger LSN Time Time Time Waits Time Time Time Buffers /Sec > Pages /Sec Pages /Sec > 51840 04:40:06 CKPTINTVL 1462:0x640018 0.0 0.0 0.0 0 0.00 0.0 0.0 1 1 2 0 > 2 0 > 51841 04:55:06 CKPTINTVL 1462:0x642018 0.0 0.0 0.0 0 0.00 0.0 0.0 1 1 2 0 > 2 0 > 51842 05:00:06 CKPTINTVL 1462:0x64b0e8 0.0 0.0 0.0 0 0.00 0.0 0.0 13 13 13 > 0 9 > 0 > 51843 05:10:06 CKPTINTVL 1462:0x64d018 0.0 0.0 0.0 0 0.00 0.0 0.0 1 1 4 0 > 2 0 > 51844 05:25:06 CKPTINTVL 1462:0x64f018 0.0 0.0 0.0 0 0.00 0.0 0.0 1 1 2 0 > 2 0 > 51845 05:40:06 CKPTINTVL 1462:0x652018 0.0 0.00 0.0 0 0.00 0.0 0.0 15 15 > 16 0 > 3 0 > 51846 05:55:06 CKPTINTVL 1462:0x654018 0.0 0.0 0.0 0 0.00 0.0 0.0 1 1 14 0 > 2 0 > 51847 06:10:07 CKPTINTVL 1462:0x656018 0.0 0.0 0.0 0 0.00 0.0 0.0 1 1 2 0 > 2 0 > 51848 06:25:07 CKPTINTVL 1462:0x658018 0.0 0.0 0.0 0 0.00 0.0 0.0 1 1 2 0 > 2 0 > 51849 06:40:07 CKPTINTVL 1462:0x65a018 0.0 0.0 0.0 0 0.00 0.0 0.0 1 1 2 0 > 2 0 > 51850 06:55:07 CKPTINTVL 1462:0x65c018 0.0 0.0 0.0 0 0.00 0.0 0.0 1 1 2 0 > 2 0 > 51851 07:00:07 CKPTINTVL 1462:0x661018 0.0 0.00 0.0 0 0.00 0.0 0.0 34 34 > 34 0 > 5 0 > 51852 07:05:07 CKPTINTVL 1462:0x664348 0.0 0.0 0.0 0 0.00 0.0 0.0 8 8 23 0 > 3 0 > 51853 07:10:07 CKPTINTVL 1462:0x668018 0.0 0.00 0.0 0 0.00 0.0 0.0 22 22 > 25 0 > 4 0 > 51854 07:25:07 CKPTINTVL 1462:0x66a018 0.0 0.0 0.0 0 0.00 0.0 0.0 2 2 17 0 > 2 0 > 51855 07:30:07 CKPTINTVL 1462:0x6d1018 0.0 0.00 0.0 0 0.00 0.0 0.0 80 80 > 60 0 > 103 0 > 51856 07:40:07 CKPTINTVL 1462:0x6d3018 0.0 0.0 0.0 0 0.00 0.0 0.0 1 1 19 0 > 2 0 > 51857 07:55:07 CKPTINTVL 1462:0x6d5018 0.0 0.0 0.0 0 0.00 0.0 0.0 1 1 2 0 > 2 0 > 51858 08:05:07 CKPTINTVL 1462:0x6d8348 0.0 0.0 0.0 0 0.00 0.0 0.0 9 9 9 0 > 3 0 > 51859 08:10:07 CKPTINTVL 1462:0x6e1018 0.1 0.0 0.0 0 0.00 0.0 0.0 40 40 40 > 0 9 > 0 > > Max Plog Max Llog Max Dskflush Avg Dskflush Avg Dirty Blocked > pages/sec pages/sec Time pages/sec pages/sec Time > 427 365 2 602 0 0 > > Regards, > > Mark > > > ******************************************************************************* > Forum Note: Use "Reply" to post a response in the discussion forum. > -- Paul Watson Tel: +1 913-674-0360 Mob: +1 913-387-7529 Web: www.oninit.com www.advancedatatools.com Failure is not as frightening as regret. If you want to improve, be content to be thought foolish and stupid. What this country needs are more unemployed politicians

↪ replying to JACQUES RENAUT

MARK JALKIEWICZ — Fri, 13 Dec 2013 15:16:47 — source: IIUG Forums & Mailing Lists

Jacques & Paul, Thanks.. figured that may have been the case but wanted to be sure nothing weird was going on. Regards, Mark

CHKPTINTVL inconsistent

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