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Alert: dbSpin num > n (or <= 1, or < 2000)

What does it mean? What do I do about it?

Example alert from the ProTop Portal:

What does it mean?

Spin-locks provide efficient, high-performance concurrency allowing many users to access the database concurrently.

What to do?

Most users should set -spin to a 4-digit value. This will provide a reasonable balance between concurrency and CPU utilization. However, there can be cases where higher values are warranted. You must carefully monitor CPU utilization when -spin is set to large values.

Do NOT believe the mythology that -spin should be a multiple of the number of CPUs. This persistent myth is enshrined on the internet but is not useful tuning advice. Setting -spin needlessly high increases CPU utilization and may hurt overall system performance. In some cases, larger values may be appropriate. CPU utilization testing and monitoring are required.

You also might get alerts for:

dbSpin <= 1: this indicates this is a Workgroup license, and -spin does not apply

dbSpin < 2000: the value shown is probably too low to be useful; follow the guidelines above

If all else fails...

Contact us at support@wss.com or use the online chat. We'll be happy to help.