Re: Informix hogging CPU

"Mike Matthews" <mmatt@halcyon.com> writes: > I am running Informix Online Server version 7.1 on D250, one cpu, HPUX > 10.10. When Informix gets hit with an SQL statement doing a few joins an a > 35,000 record database, the system just crawls while the statement > executes (takes about 5 minutes). No one can login and if you are logged > in, you get a response to hitting ENTER about 40 seconds after hitting it. > TOP shows oninit processes running with a priority of -16 and oninit > processes using about 90% of the CPU. I don't see any obvious errors in > the ONCONFIG file. Has anyone seen anything like this and is there any way > of configuring Informix to use less CPU? Yes, but then it would be even slower :-) Seriously, are you running with NOAGE? When we had HP-UX 10.01 this would behave almost the same. Turned it off and haven't tried it since. There are other things to check as well. First thing is of course update statistics and set explain on. Check if you have more than one virtual shared memory segment (onstat -g seg; should have only one i class V, increase SHMVIRTSIZE otherwise). Check your LANG env.variable. We had big problems until we unset this! How long do the checkpoints take? Reduce LRU_MAX_DIRTY and LRU_MIN_DIRTY (we use 4 and 8) if the checkpoints run for > 5 sec. This depends on the kind of applications you are running. -- 'yvind Gjerstad Systems dept Tollpost-Globe AS N-6301 'ndalsnes/Norway E-mail: ogj@it.tollpost.no Phone: +47 7122 6663 Fax: +47 7122 6694