Single application + NUMA nodes assignment behavior

Question

System specs - CPUs:4, total cores:192, NUMA nodes:4, Windows Server 2019

I have quick question on running a CPU intensive application, in both cases

(a)one instance per user in case of server 2019

(b)multiple instances with in the same user session (windows 10 or server 2019)

By default if you run multiple instances of a single application that is CPU intensive, the max Windows can assign it to is 64 cores (max limit for a NUMA node on 64bit OS) and any subsequent instances of the same application is assigned to the same node.

Now, I am interested to know what happens if the second instance is opened in another user environment? Will it still assign it to the same node as it did for the first user?

Is there any way to assign multiple instances of an application to different nodes?

I could have tested it, but the software I am trying to test doesn't allow multiple instances across multi user accounts and it assigns to only one node within the same user session. I have another version of that software that I can try, but before moving its license and all to this setup, would like to know.

thanks for any input

Answer 1

Hi,
As far as I know, the APP needs to be the processor group aware in order to realize its requirements. Use CPUs across processor groups. Otherwise it can't be done.
A process can only be assigned to a single NUMA node. We could not force a single instance to run on more than one NUMA node. Giveing the purpose of NUMA, and also the secondary purpose of allowing >64 CPU cores on an OS that uses 64-bit CPU.
Hope this helps and please help to accept as Answer if the response is useful.
Best Regards,
Carl

Answer 2

We could not force a single instance to run on more than one NUMA node

How about multiple instances? Can you make multiple instances run on different node?