RE: Long check points

1. FYI your whole onconfig file would be useful. 2. how many buffers do you have? 3. watch onstat -R (for monitoring LRU queues) the f's are clean the m's are dirty The dirty pages are all flushed at a checkpoint. The question is what are these numbers before the checkpoint starts. In other words, are your Cleaners starting to clean at 4 percent and getting down to 2 percent? I am guessing due to the foreground writes you are experiencing that maybe you are not able to keep up with cleaning your buffers. Other questions. 1. Does the box look busy when you look at it with vmstat? 2. Are their other applications on this box? 3. How much memory is on the box? 4. What do the results from iostat look like. Will >===== Original Message From "Hans Siebrand" <hans.siebrand@iluka.com> ===== >Hans Siebrand wrote in message ... >>Performance on one of the servers at my site is taking an exceptionally log >>time for checkpoints, in the order of 120 to 160 seconds. >> >>What should I be looking for to shorten the check point length other than >>decreasing CKPTINTVL. >> >> >>Hans > > >Out put from the system is: > >OS: SCO 5.0.5 OpenServer >IO: KAIO > >CLEANERS 8 # Number of buffer cleaner processes >LRUS 12 # Number of LRU queues >LRU_MAX_DIRTY 4 # LRU percent dirty begin cleaning limit >LRU_MIN_DIRTY 2 # LRU percent dirty end cleaning limit> > >cpasx001:informix:p4 /tmp >onstat -p > >Informix Dynamic Server Version 7.30.UC2 -- On-Line -- Up 14:10:28 -- >258048 Kbytes > >Profile >dskreads pagreads bufreads %cached dskwrits pagwrits bufwrits %cached >6937873 4082615 105137757 93.40 785323 1304339 13490224 94.18 > >isamtot open start read write rewrite delete commit >rollbk >51664971 152396 1274885 45273034 1032036 6901 25909 15982 2 > >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 0 105 1657.80 692.63 86 335 > >bufwaits lokwaits lockreqs deadlks dltouts ckpwaits compress seqscans >300807 0 49283024 0 0 44 37206 5922 > >ixda-RA idx-RA da-RA RA-pgsused lchwaits >272958 10034 4112289 4389657 18875 > > > > > >cpasx001:informix:p4 /tmp >onstat -D > >Informix Dynamic Server Version 7.30.UC2 -- On-Line -- Up 14:14:11 -- >258048 Kbytes > >Dbspaces >address number flags fchunk nchunks flags owner name >8c84613c 1 1 1 1 N informix rootdbs >8c847a18 2 1 2 1 N informix physical_logs >8c847ad4 3 1 3 1 N informix >logical_logs_1 >8c847b90 4 1 4 1 N informix >logical_logs_2 >8c847c4c 5 1 5 1 N informix temp_1 >8c847d08 6 2001 6 1 N T informix temp_2 >8c847dc4 7 1 7 1 N informix temp_3 >8c847e80 8 2001 8 1 N T informix temp_4 >8c847f3c 9 1 9 1 N informix temp_5 >8c86d828 10 2001 10 1 N T informix temp_6 >8c86d8e4 11 1 11 1 N informix temp_7 >8c86d9a0 12 1 12 3 N informix wslis >8c86da5c 13 1 15 3 N informix wslistest >8c86db18 14 1 18 1 N informix datamart >8c86dbd4 15 1 19 1 N informix gis >8c86dc90 16 1 20 2 N informix trim >8c86dd4c 17 1 21 1 N informix reports >8c86de08 18 1 22 1 N informix misc >8c86dec4 19 1 24 1 N informix trimtest > 19 active, 2047 maximum > >Chunks >address chk/dbs offset page Rd page Wr pathname >8c8461f8 1 1 0 1329 148 /dev/rdbirootl >8c846654 2 2 0 12 191965 /dev/rdbiphyslogl >8c846730 3 3 0 220712 131796 /dev/rdbilogs1l >8c84680c 4 4 0 217191 131209 /dev/rdbilogs2l >8c8468e8 5 5 0 400 1249 /dev/rdbic1l >8c8469c4 6 6 0 44084 37232 /dev/rdbic2l >8c846aa0 7 7 0 849 1254 /dev/rdbic3l >8c846b7c 8 8 0 42421 34228 /dev/rdbic4l >8c846c58 9 9 0 5224 11411 /dev/rdbic5l >8c846d34 10 10 0 54182 44964 /dev/rdbic6l >8c846e10 11 11 0 833 1255 /dev/rdbic7l >8c846eec 12 12 25600 1057580 376542 /dev/rdbic1l >8c846fc8 13 12 25600 74212 728 /dev/rdbic2l >8c8470a4 14 12 25600 1774178 339321 /dev/rdbic3l >8c847180 15 13 25600 8 0 /dev/rdbic4l >8c84725c 16 13 25600 3 0 /dev/rdbic5l >8c847338 17 13 25600 3 0 /dev/rdbic6l >8c847414 18 14 25600 28148 0 /dev/rdbic7l >8c8474f0 19 15 525600 8 0 /dev/rdbic7l >8c8475cc 20 16 575600 371851 65 /dev/rdbic7l >8c8476a8 21 17 625600 2983 0 /dev/rdbic7l >8c847784 22 18 675600 1198 0 /dev/rdbic7l >8c847860 23 16 725600 192838 1040 /dev/rdbic7l >8c84793c 24 19 825600 158 0 /dev/rdbic7l > 24 active, 2047 maximum > > >onstat -F> >Informix Dynamic Server Version 7.30.UC2 -- On-Line -- Up 14:14:47 -- >258048 Kbytes > > >Fg Writes LRU Writes Chunk Writes >105 530998 197904 > >address flusher state data >8c8484c4 0 I 0 = 0X0 >8c848974 1 I 0 = 0X0 >8c848e24 2 I 0 = 0X0 >8c8492d4 3 I 0 = 0X0 >8c849784 4 I 0 = 0X0 >8c849c34 5 I 0 = 0X0 >8c84a0e4 6 I 0 = 0X0 >8c84a594 7 I 0 = 0X0 > states: Exit Idle Chunk Lru > > >onstat -m> >16:16:06 Checkpoint Completed: duration was 0 seconds. >16:26:25 Checkpoint Completed: duration was 13 seconds. >16:31:32 Checkpoint Completed: duration was 4 seconds. >16:36:49 Checkpoint Completed: duration was 14 seconds. >16:42:41 Checkpoint Completed: duration was 49 seconds. >16:48:31 Checkpoint Completed: duration was 47 seconds. >16:54:16 Checkpoint Completed: duration was 42 seconds. >17:00:11 Checkpoint Completed: duration was 52 seconds. >17:05:57 Checkpoint Completed: duration was 43 seconds. >17:11:43 Checkpoint Completed: duration was 43 seconds. >17:17:32 Checkpoint Completed: duration was 46 seconds. >17:24:18 Checkpoint Completed: duration was 103 seconds. >17:29:30 Checkpoint Completed: duration was 9 seconds. >17:35:25 Checkpoint Completed: duration was 52 seconds. >17:41:26 Checkpoint Completed: duration was 57 seconds. >17:46:29 C