CPU Co-Stop

David Klee discusses an important hypervisor-level metric:

VMware’s CPU Co-Stop metric shows you the amount of time that a parallelized request spends trying to line up the vCPU schedulers for the simultaneous execution of a task on multiple vCPUs. It’s measured in milliseconds spent in the queue per vCPU per polling interval. Higher is bad. Very bad. The operating system is constantly reviewing the running processes, and checking their runtime states. It can detect that a CPU isn’t keeping up with the others, and might actually flag a CPU is actually BAD if it can’t keep up and the difference is too great.

This is extremely useful information for DBAs in virtualized environments.  My crude and overly simplistic answer is, don’t over-book vCPUs on hosts running important VMs like your SQL Server instances.

Related Posts

Automatically Fix Those VLFs

Tracy Boggiano has a script which will fix log files with high virtual log file counts: First part of the process if to capture the info from DBCC LOGINFO or if you are ready for 2017 the new dmv sys.dm_db_log_stats into a table you can read later to know how many VLFs exist in your […]

Read More

Schema Comparison With Visual Studio

Arun Sirpal shows off the Schema Compare functionality within Visual Studio: A very common requirement which can be satisfied by various tools. Personally I like using Visual Studio 2017 Community Edition and I thought I would do a quick overview of it. First thing, you can find the download from this link: https://www.visualstudio.com/downloads/  and once installed (making […]

Read More

Categories

March 2016
MTWTFSS
« Feb Apr »
 123456
78910111213
14151617181920
21222324252627
28293031