0

I'm running SQL Server Web on a VM with 20 cores. (I know, Web edition can only make use of 16 cores but I'll get that resolved soon when I upgrade to Standard).

But what's funny to me is that for some reason, one of the cores is always at 100%. I've never seen this before as usually the load is spread out between all the cores.

Anyone experience this?

enter image description here

The long running queries/transactions are all types as this is handling an ecommerce site. The transactions themselves aren't the issue as I can paste them into new query window and they run fast so it sounds like it's just the sheer amount of them. Also, when traffic does down during off peak hours, I no longer have the issue.

There are no other applications running on the server that is using more than 1-2% of the CPU.

3
  • I suspect RSS as Mo64 suggested, assuming this is an OLTP workload. – Dan Guzman Apr 28 '20 at 20:12
  • RSS sounds promising but I've just checked and it seems to be enabled. I guess I can look to tweak it. First thing I noticed is that Max Number of RSS Processors is set to 16. Since I have 20 cores, should I change that number to 20? – User Apr 28 '20 at 21:31
  • If RSS is already enabled (using more than a single core), I wouldn't bother changing it as my suspicion was wrong. I have seen these exact symptoms on a high-volume OLTP box that limited throughput but that doesn't seem to be the case here. – Dan Guzman Apr 28 '20 at 22:18
2

could be a few things, start by checking the wait types. A couple I have seen RSS Receive Side Scaling is not enabled so all n/w traffic is handled by a single CPU or Ghost cleanup running - this is a system SPID responsible for removing deleted records and runs on a single core https://docs.microsoft.com/en-us/sql/relational-databases/ghost-record-cleanup-process-guide?view=sql-server-ver15

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.