Parfeval memory leak? Clear memory on parallel workers?

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Hi,
I have some sort of memory leak when using parfeval.
I have a function that starts a number of parfeval-computations and then uses fetchNext in a loop to retrieve all results.
The memory taken up by the Matlab instances in my parallel pool grows with each execution of the function that uses parfeval.
My question: Am I doing something wrong? Do I have to explicitly clear the memory of the workers after using parfeval? How do I do this? I tried "pctRunOnAll clear all" but it did not free up any memory on the workers (just the client instance).
Right now, the only way I can clear this memory is to shut down and re-start my parallel pool, but that's not a feasible solution for my application.
Thanks, Matthias
  3 Comments
Atakan Atay
Atakan Atay on 25 Mar 2020
Edited: Atakan Atay on 25 Mar 2020
Hi Matthias,
Currently I experience the very same problem. How did you manage to solve it? I would really appreciate your help.
Thanks for your time.
Francis Plamondon
Francis Plamondon on 18 Nov 2020
Hello,
I also recently struggled with parfeval. I would get 'out of memory' errors after several hours of running a huge batch of jobs.
Here is what I found out: each parallel.FevalFuture object holds a Diary property that contains everything that was displayed in the console window for each job. Since I had a function use disp() for monitoring purpose, it was being recorded in the Diary variable, eventually filling all the memory.
After commenting out the disp function, the memory stopped slowly increasing.

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Accepted Answer

Edric Ellis
Edric Ellis on 15 Dec 2014
Please could you try applying the workaround from this bug report. (The bug report mentions mapreduce, but it includes a fix that affects only parfeval).
  1 Comment
Seth
Seth on 13 Feb 2015
I have a similar problem and tried using this patch and now get errors indicating "no method 'createInstance' with matching signatures found for class 'com.mathworks.toolboox.distcomp.objects.EntityFileProxy'
Do you have any other suggestions? I was running two workers with PARFEVAL and seeing 3gb increase in RAM used each call to them. (The PARFEVAL commands are in a loop)
Thanks.

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