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Posted Tuesday, March 19, 2013 5:48 AM


Mr or Mrs. 500

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Hi,

I ran some DMV queries to get a server's health and came across some questions..
* The signal waits query gave almost 20% for %signal (cpu) waits
* The CPU history says that SQL Server uses 1 to 0% of CPU but other processes use 10 to 30%
* The top waits are PREEMPTIVE_OS_AUTHENTICATIONOPS, ASYNC_NETWORK_IO and PREEMPTIVE_OS_LOOKUPACCOUNTSID (I had LATCH and CXPACKET but creating an index made them disappear)

Who can I determine what's causing the signal cpu waits and what type of waits are PREEMPTIVE_%?!

Thanks,
Pedro




If you need to work better, try working less...
Post #1432583
Posted Tuesday, March 19, 2013 6:05 AM


Mr or Mrs. 500

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Other extra information....
I don't have access to the machine just the SQL instance.
The SO admin said there are other instances on the server.
The server has 16 cores (4 physical) and 56GB RAM. My instance has a limit of 8GB.

Thanks,
Pedro




If you need to work better, try working less...
Post #1432588
Posted Wednesday, March 20, 2013 7:42 AM


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Do you have performance problems on the server? Given that you are using only 1% of CPU, I would be surprised if you did. And if you DO, it almost certainly isn't because of CPU problems. I would look for locking and IO stalls as a more likely cause. waits aren't just about percentages - how many and most importantly how LONG are they taking per unit time is what counts.

Best,

Kevin G. Boles
SQL Server Consultant
SQL MVP 2007-2012
TheSQLGuru at GMail
Post #1433210
Posted Wednesday, March 20, 2013 7:52 AM


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PiMané (3/19/2013)
* The CPU history says that SQL Server uses 1 to 0% of CPU but other processes use 10 to 30%


What else is running on the particular server?


_____________________________________
Pablo (Paul) Berzukov

Author of Understanding Database Administration available at Amazon and other bookstores.

Disclaimer: Advice is provided to the best of my knowledge but no implicit or explicit warranties are provided. Since the advisor explicitly encourages testing any and all suggestions on a test non-production environment advisor should not held liable or responsible for any actions taken based on the given advice.
Post #1433221
Posted Wednesday, March 20, 2013 8:16 AM


Mr or Mrs. 500

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There is 2 other SQL Server instances. One has 100 databases of an ERP software.
Can the cpu signal waits be related to the ERP databases be more demanding on CPU an allocate more CPU to them?

Thanks,
Pedro




If you need to work better, try working less...
Post #1433243
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