Re: [HTCondor-users] Does HTC limit CPU usage on macOS?

[Greg Thain <gthain@xxxxxxxxxxx>]

On 7/27/25 19:45, Neil Clayton via HTCondor-users wrote:
> Iâve been learning HTC over the weekend, and have a small cluster working, across 3 machinesm a linux box (50+ cores), a M4 Mac Pro, and some other linux thing.
>
> The macOS box (named speedy4) has condor executor installed manually, as root.
> An executor linux box (50+ cores) exists, named âhappyâ.
> The central manager + submit + negotiator (everything else, *not* an executor) is on a separate linux box (named: containery).
>
> I can queue + run jobs over the machines in the cluster fine (itâs a java universe btw).  Using dynamic slots, jobs are allocated as Iâd expect.
> I am queuing directly from âcontaineryâ (a submit node).


HTCondor doesn't explicitly limit cpu on the Mac, but Java universe jobs 
are passed the memory-limiting option "-Xmx" to the java runtime, which 
should roughly correspond to the "request_memory" command in the submit 
file. We have seen some cases where a lower allocation of memory to the 
java job causes the garbage collector to work a lot more than it 
otherwise would, and slow the job down. If you run it with a much 
larger request_memory, does it get faster?


-greg