I increased numworkers to 3 but still receiving an error message that they are set to a maximum of 2 and I cannot figure out how to change this.

I receive this error message:

"You requested a minimum of 3 workers, but the cluster "local" has the NumWorkers property set to allow a maximum of 2 workers. To run a communicating job on more workers than this (up to a maximum of 512 for the Local cluster), increase the value of the NumWorkers property for the cluster. The default value of NumWorkers for a Local cluster is the number of physical cores on the local machine."

I changed the local cluster property to allow 3 workers but am still receivin this error message.

Answer 1

[Raymond Norris]

How did you set the number of workers? Did you set it in the Cluster Manager Profile? Or did you set it to something similar to:

local = parcluster('local');
local.NumWorkers = 5;
saveProfile(local)
pool = local.parpool(5);

If the former, make sure that after you set the number of workers that if you had a variable (local in my example above), that you call parcluster again -- that is, the cluster object won't see the updated value until you call parcluster again. The former should work fine.

Of course, it also begs the question, if you have 2 cores, are you sure you want to start 3 workers (plus the MATLAB client that also running.)

[Daryn Cass]

Thank you for your reply!

I did it in the cluster manager profile. I am using a GUI (brainstorm) and another application within that (brainsuite) in Matlab, so I am not sure since these run the code I don't know where in the process I would enter this if it does not work by updating in the cluster manager profile.

I am trying to start 3 workers on 2 cores because this is specifically what the GUI requires (in order to perform something called MRI segmentation)

Sincerely,

Daryn Cass

[Raymond Norris]

So long as you've set it in the Cluster Manager Profile, quit out of MATLAB (including brainstorm and brainsuite), restart it, and check if you still have the issue. If so, contact Technical Support ([e-mail]), they'll be able to resolve this for you.