fjd 0.1

File-based job distribution for everyone

File-based job distribution. A straightforward pull-model for computational tasks, working with the assumption that all CPUs/cores can access a shared home directory.

Usage

First, start a dispatcher: python <path-to-fjd>/dispatcher.py

Then, start one or more workers, like this: python <path-to-fjd>/worker.py

Now the dispatcher waits for jobs in the jobqueue directory (which it creates if it does not yet exist). Workers announce themselves in the workerqueue directory, where the dispatcher will find them.

All you have to do now is to put jobs in the queue. You do this by putting a file per job in the jobqueue directory. The file should adhere to the general configuration file standard. Here is an example:

[control] executable: python test/ajob.py logfile: data/job0.dat

[params] param1: value0

Where you specify which command to execute and where results should go.

Your executable (the “job”) gets this configuration file passed as a command line argument. This way, it can see for itself in which logfile to write to.

Take care to get the relative paths correct (or simply make them absolute): If the paths are relative, the path to the executable should be relative to the workers working directory, whereas the path to the logfile should be relative to the jobs working directory.

In addition, you can put other job-specific configuration in there for the executable to see, as I did here in the [params]-section (in fact, only the [control]-section is fjd-specific).

You can see how it all comes together by looking at the simple example in the test directory where there is one script that represents a job and one that creates ten jobs and puts them in the queue.

To run this test, first navigate to the fjd directory. Then, start a dispatcher and at least one worker and run a script that creates the jobqueue. Then, observe. Here are the commands - you should issue them all in their separate console window, as the first two are continuous services:

$ python dispatcher.py $ python worker.py $ python test/create_jobs.py

(Changes are not tracked yet, too early …)