Question Re: Unbalanced CPU usage in Technology Q&A

Unbalanced CPU usage

Former Member — Tue, 18 May 2021 15:41:08 GMT

Our customer is complaining about decreased performance after migrating from SA16 to SA17. I've investigated a lot and have tried to compare the old and new server, without finding any big differences. This is the log in the server console after startup:

Processors detected: 4 logical processor(s) on 4 core(s) on 1 physical processor(s)
Processor license restriction (Workgroup Edition): all logical processors on all cores on up to 2 physical processors
Processor license restriction (licensed processors): all logical processors on all cores on up to 2 physical processors
This server is licensed to use: all logical processors on all cores on up to 2 physical processors
Processors in use by server: 4 logical processor(s) on 4 core(s) on 1 physical processor(s)

The performance tab in Task manager shows that one core is at 100% constantly, and the 3 others is just idling. Is there anything we can adjust either in the dbsrv17 startup of the service or using options? I find it very strange that just one of the 4 cores is utilized.

br,

Bjarne Maritech

Re: Unbalanced CPU usage

VolkerBarth — Wed, 19 May 2021 02:57:08 GMT

Just to clarify:

So the following call will show in_use = 1 for all sockets/cores/threads?

call sa_cpu_topology();

Re: Unbalanced CPU usage

Breck_Carter — Wed, 19 May 2021 13:28:00 GMT

Please show us screenshots of (a) Task Manager - Performance tab, and (b) Resource Monitor - CPU tab.

On my Windows 10 consumer-grade computer, the Task Manager - Performance tab shows one CPU graph only, which is the overall CPU usage of the 1 socket - 4 cores - 8 logical processors hardware architecture.

The Resource Monitor - CPU tab shows 10 CPU graphs: CPU - Total, Service CPU Usage, and CPU 0 through CPU 7 (and 4 of them are "Parked").

Run this query in SA17 and tell us what you see in the Resource Monitor (for me, it shows CPU 0 through 7 at 100%):

SELECT COUNT_BIG(*) 
  FROM SYSTABCOL AS A 
       CROSS JOIN SYSTABCOL AS B
       CROSS JOIN SYSUSER AS C;

Re: Unbalanced CPU usage

Former Member — Thu, 20 May 2021 06:06:40 GMT

It looks like it was an unfinished prosess in Windows 2019 Server which caused this. The UT dept. investigated the issue and restarted the server.

Now, the CPU graphs is balanced as it should.

Thnx,

Bjarne