Having problem in running parfor loop on my system, getting messages" A worker aborted during execution of the parfor loop. "?

I have a code that uses parfor. Intrestingly when I use that code earlier on another machine on windows it does not give an error and was run properly.

However, when I try to run that code on a new machine also on windows it always gives me the following error:

Warning: A worker aborted during execution of the parfor loop. The parfor loop will now run again on the remaining workers. 
> In parallel.internal.parfor/ParforEngine/handleIntervalErrorResult (line 285)
In parallel.internal.parfor/ParforEngine/getCompleteIntervals (line 227)
In parallel_function>distributed_execution (line 742)
In parallel_function (line 574)
In MolecularNetworking_LongBINOMIAL_AverageFOR_4PAR (line 15) 
Parallel pool using the 'Processes' profile is shutting down.
Error using parallel.internal.parfor.ParforEngine/rebuildParforController (line 134)
The parallel pool that parfor was using has shut down. To start a new parallel pool, run your parfor code again or use parpool.

Error in parallel.internal.parfor.ParforEngine/handleIntervalErrorResult (line 304)
obj.rebuildParforController();

Error in parallel.internal.parfor.ParforEngine/getCompleteIntervals (line 227)
[r, err] = obj.handleIntervalErrorResult(r);

Error in MolecularNetworking_LongBINOMIAL_AverageFOR_4PAR (line 15)
parfor binomialaverageloop=1:NumberofBINOMIALTrials
    
    Caused by:
    Error using parallel.internal.parfor.ParforEngine/buildParforController (line 93)
    No running parallel pool. To start a new parallel pool use parpool.

I have tried it several times, always the same error is encountered. What should I do?

Somewhere, some one suggested to increase memory per core. I am using windows and do not know how to do that.

[Edric Ellis]

There are several possibilities as to why your workers are aborting during parfor. Running low on memory is one possibility - try opening a parallel pool with a lower number of workers before running your code, for example parpool("Processes",2). If you have crash dump files (you'll see a warning when a pool starts up telling you about these), then there might be some other problem. In any case, I would recommend contacting MathWorks support who can work through some more diagnostic steps to help get to the bottom of this.

[Ankit Gaur]

Even parfor with one worker does not work. For example I tried running the same code with

parpool("Processes",1)

But still got error

Starting parallel pool (parpool) using the 'Processes' profile ...
Connected to parallel pool with 1 workers.

ans = 

 ProcessPool with properties: 

            Connected: true
           NumWorkers: 1
                 Busy: false
              Cluster: Processes (Local Cluster)
        AttachedFiles: {}
    AutoAddClientPath: true
            FileStore: [1x1 parallel.FileStore]
           ValueStore: [1x1 parallel.ValueStore]
          IdleTimeout: 30 minutes (30 minutes remaining)
          SpmdEnabled: true

Warning: A worker aborted during execution of the parfor loop. The parfor loop will now run again on the remaining workers. 
> In parallel.internal.parfor/ParforEngine/handleIntervalErrorResult (line 285)
In parallel.internal.parfor/ParforEngine/getCompleteIntervals (line 227)
In parallel_function>distributed_execution (line 742)
In parallel_function (line 574)
In MolecularNetworking_LongBINOMIAL_AverageFOR_4PAR (line 15) 
Error using parallel.internal.parfor.ParforEngine/rebuildParforController (line 134)
The parallel pool that parfor was using has shut down. To start a new parallel pool, run your parfor code again or use parpool.

Error in parallel.internal.parfor.ParforEngine/handleIntervalErrorResult (line 304)
obj.rebuildParforController();

Error in parallel.internal.parfor.ParforEngine/getCompleteIntervals (line 227)
[r, err] = obj.handleIntervalErrorResult(r);

Error in MolecularNetworking_LongBINOMIAL_AverageFOR_4PAR (line 15)
parfor binomialaverageloop=1:NumberofBINOMIALTrials
    
    Caused by:
    Error using parallel.internal.parfor.ParforEngine/buildParforController (line 93)
    No running parallel pool. To start a new parallel pool use parpool.
    
    Parallel pool using the 'Processes' profile is shutting down.
    This parallel pool has been shut down.
    
    Caused by:
    The client lost connection to worker 1. This might be due to network problems, or the interactive communicating job might have
    errored.

Answer 1

[Kautuk Raj]

It seems like you are encountering an issue related to the parallel pool shutting down unexpectedly during the execution of your parfor loop. This is a known issue, and you might find relevant information in this bug report from MathWorks: https://www.mathworks.com/support/bugreports/3187300

Specifically, it is suggested to increase the value of the MW_PCT_TRANSPORT_HEARTBEAT_INTERVAL environment variable to a large integer value, such as 100000, before opening your MATLAB session.