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viperbyte
Posting Yak Master
132 Posts |
 Posted - 2012-12-11 : 09:27:57
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| Good morning all.I've been reading and cramming lately on the subject of Performance tuning. Heavy CPU use comes up a lot in many of the articles that I read. It comes up as something to identify first during decision making time as far as how to go about to solve a particular performance problem many times. What method do we use to determine that CPU is stressed? All I know of is clicking on task manager and looking at performance, which according to me is fine because it varies from 0% to 28% throughout the day. Do you folks identify CPU stress in a different way? What do we call this, instead of saying "CPU Stress"? While we're at it, what's this yak thing I see all over everyone's user name? Isn't a yak an animal? |
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robvolk
Most Valuable Yak
15732 Posts |
Posted - 2012-12-11 : 09:51:34
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| The mini-bible on waits: http://www.sqlskills.com/blogs/paul/post/wait-statistics-or-please-tell-me-where-it-hurts.aspxThe main one to look for in diagnosing CPU pressure is SOS_SCHEDULER_YIELD. Paul gives guidelines on how much represents an overloaded CPU. If you don't see those levels then you're not likely CPU bound, even if you're at 50% CPU utilization all the time.SQLTeam Yak History: http://www.sqlteam.com/forums/topic.asp?TOPIC_ID=61012 |
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viperbyte
Posting Yak Master
132 Posts |
Posted - 2012-12-13 : 09:05:51
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| Thanks for the info. |
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jackv
Master Smack Fu Yak Hacker
2179 Posts |
Posted - 2012-12-13 : 09:38:34
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| A high percentage SOS_SCHEDULER_YIELD does not always mean CPU pressure. Use perfmon counters to cross-check.Assess response from sys.dm_os_schedulers . From BOL “Returns one row per scheduler in SQL Server where each scheduler is mapped to an individual processor. Use this view to monitor the condition of a scheduler or to identify runaway tasks”Jack Vamvas--------------------http://www.sqlserver-dba.com |
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How To Identify CPU Problem?