excessive CPU usage every hour

[JCR]

Every hour, the SQLSERVER 7.0 process (SQLSERVR.EXE) that runs in WINDOWS NT begins to use 100% of the CPU process time. This lasts for about 8 minutes and then drops down to normal CPU usage. This occurs even when there are no applications accessing the data. There are no JOBS or MAINTENANCE scheduled that we are aware of. Any ideas on what is going on?

 

[foxdev]

My guess is that it is writing out the dirty data cache to disk, especially if there had been moderate-heavy activity in the preceding hour.

If not, then guess #2 is that it is updating its statistics, which is more likely if a lot of data has been added within the preceding hour or two.

My suggestion is to run a SQL Server Profiler trace on it and see what occurs during the busy time. Robert Bradley

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[fluteplr]

If it is really every hour, I would make really sure that there are no scheduled jobs, backups etc. I would be suprised if writting dirty cache data or updating statistics would run on that strict a schedule.

 

[vnad]

It might be due to checkpointing. Look in books online and read about it. We had to change our Recovery Interval to prevent this. It runs a pretty strict schedule during high volume periods.

Hope this helps.

Dan

 

[MAK9974]

if its a checkpoint issue , do a tran log backup every 15 min.