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 High CPU utilisation

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ranvir_2k
Posting Yak Master

180 Posts

Posted - 2013-11-27 : 10:10:35
Hi all,

I'm seeing high CPU usage on my SQL Server box. It often goes up to 90% and SQL Server is the culprit.

This server is the subscriber node of a merge replication set up.

When I run sp_who2 I can see no active running processes. So why is SQL Server responsible for such high CPU utilization?

What could be the issue? How can I investigate this further?

tkizer
Almighty SQL Goddess

38200 Posts

Posted - 2013-11-27 : 13:01:38
These are the typical issues on my systems with high CPU:

1. Missing indexes
2. Inefficient code
3. Out-of-date statistics
4. Bad execution plan (see #1 and #2)
5. Insufficient memory, causing physical IOs rather than getting them from memory

Regarding sp_who2...run a server-side trace to capture the load and then sort it by Duration DESC and then another query to sort it by Reads DESC. You are likely going to find very high reads. How do I define high reads? Well it depends on the system, but I definitely work on the ones with reads into the hundreds of thousands or millions. When I run a trace, I often will only capture Reads>5000.

Tara Kizer
SQL Server MVP since 2007
http://weblogs.sqlteam.com/tarad/
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Paul J. Brooks

7 Posts

Posted - 2013-12-05 : 06:44:51
This is very important information for every one and beneficial.I wanna discuss on this topic so please any one interested me so please reply me.Thanks for sharing this information.

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