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Monitor (Check Indexes) taking up CPU time
Posted: Tue Sep 30, 2003 6:23 pm
by marcos1
Hello,
We have a large webinator DB (over 1.4 million rows) and have recently started experiencing a problem where Monitor (Check Indexes) takes up 50% or more of the CPU time for extended periods of time (most of the time, in fact)-- slowing down everything else the server is trying to do. This only started in the last few days and we have not added any rows for several weeks.
Is this normal behavior for large tables with big indexes or might something be awry?
Thanks,
Evalumetrix
Monitor (Check Indexes) taking up CPU time
Posted: Tue Sep 30, 2003 7:30 pm
by John
One possibility is that the index update is failing for some reason, and then gets relaunched. You can check the monitor.log file for any errors there. Also if you look in the directory holding the database you should see some files ending _T.btr, which should not be more than a couple of K. If they are larger it indicates an out of date index.
Monitor (Check Indexes) taking up CPU time
Posted: Tue Sep 30, 2003 8:31 pm
by marcos1
There are a number of files in the index directory that start with T15788a including one that end in _T.btr (62K) and a table of the same name (.dat). In monitor.log there is an error trying to find a table that it looks like was manually deleted by mistake (instead of dropping) -- I went ahead and dropped it. Can we just delete the T15788a stuff (it is not listed in SYSTABLE or SYSINDEXES)?
Thanks,
Evalumetrix
Monitor (Check Indexes) taking up CPU time
Posted: Wed Oct 01, 2003 10:49 am
by mark
Yes, if it's not listed in SYSINDEX you can delete it.
Monitor (Check Indexes) taking up CPU time
Posted: Wed Oct 01, 2003 11:01 am
by marcos1
OK. We deleted those file and we dropped and started recreating all indexes -- which seemed to fix things -- but when it got to rebuilding one of the indexes (xhtmlid) everything slowed to a stop. The machine actually kicked us out of the ssh session -- but right before that I could see that Monitor (the primary process) was taking up 99.9 percent of the CPU. Could this indicate that the table itself has some corruption? Other ideas?
Thanks,
Evaluemtrix
Monitor (Check Indexes) taking up CPU time
Posted: Wed Oct 01, 2003 4:24 pm
by John
No, the index build process can be fairly CPU intensive, and it will use as much CPU as available. It is strange the ssh session would have been killed. How much RAM is on the system, and do you have any other process that might use a lot of memory?