Getting output from parallel jobs that would regularly go to a diary
16 views (last 30 days)
Show older comments
Using the parallel computing toolbox, is it possible to get each individual job spawned by createTask to write output to a diary, so that one can get feedback on one's jobs progress? For example, in the following silly example, I'd like to write the output from fsolve's displays to separate files as they are generated, so that I can see where things are going bad. It appears that error messages are generated only at the end of a job, which is not at all helpful if your job is schedule to run for a week. Here's an example that illustrates the first point, but not the second (because the job runs quickly).
parallel.defaultClusterProfile('local');
c = parcluster();
j = createJob(c);
numCores = 4;
pauseTime = 2;
for ii=1:numCores
param = {1/rand,pauseTime*(ii-1)};
t = createTask(j,@dumbProblem,3,param);
end;
disp(['Submitting ' num2str(numCores) ' copies of dumbProblem']);
submit(j);
disp(['job submitted at ' datestr(now) ', now waiting']);
wait(j,'finished');
disp(['job finishing at ' datestr(now) ]);
OutputArgs = fetchOutputs(j);
errmsgs = get(j.Tasks, {'ErrorMessage'});
nonempty = ~cellfun(@isempty, errmsgs);
celldisp(errmsgs(nonempty));
disp(OutputArgs)
keyboard;
function [soln,fval,exitflag] = dumbProblem(param,pauseTime);
pause(pauseTime);
[soln,fval,exitflag,output] = fsolve(@(x) sin(param*x),[-4,
4],optimoptions('fsolve','Display','iter'))
sprintf('soln');
disp(output);
OutputArgs gives me the solns if they are generated, but if the engine fails to solve the problem, I don't see any way of getting any feedback while the program is still running.
Thanks! leo
0 Comments
Answers (1)
Thomas Ibbotson
on 21 Oct 2014
Remove the line with:
wait(j, 'finished')
Then this allows you to get the tasks' diary output while the job is still running with:
j.Tasks.Diary
See Also
Products
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!