Documentation

Program a Job on a Local Cluster

In some situations, you might need to define the individual tasks of a job, perhaps because they might evaluate different functions or have uniquely structured arguments. To program a job like this, the typical Parallel Computing Toolbox™ client session includes the steps shown in the following example.

This example illustrates the basic steps in creating and running a job that contains a few simple tasks. Each task evaluates the sum function for an input array.

1. Identify a cluster. Use parallel.defaultClusterProfile to indicate that you are using the local cluster; and use parcluster to create the object c to represent this cluster. (For more information, see Create a Cluster Object.)

   parallel.defaultClusterProfile('local');
   c = parcluster();

2. Create a job. Create job j on the cluster. (For more information, see Create a Job.)

   j = createJob(c)

3. Create three tasks within the job j. Each task evaluates the sum of the array that is passed as an input argument. (For more information, see Create Tasks.)

   createTask(j, @sum, 1, {[1 1]});
   createTask(j, @sum, 1, {[2 2]});
   createTask(j, @sum, 1, {[3 3]});

4. Submit the job to the queue for evaluation. The scheduler then distributes the job's tasks to MATLAB^® workers that are available for evaluating. The local cluster might now start MATLAB worker sessions. (For more information, see Submit a Job to the Cluster.)

   submit(j);

5. Wait for the job to complete, then get the results from all the tasks of the job. (For more information, see Fetch the Job's Results.)

   wait(j)
   results = fetchOutputs(j)
   results = 
       [2]
       [4]
       [6]

6. Delete the job. When you have the results, you can permanently remove the job from the scheduler's storage location.

   delete(j)