How to use Magellan

An explanation on how to write and use a module for Magellan to solve your problem.

Defining Your Problem

Finding a solution to your problem with Magellan is as easy writing one Python class. Well, mostly.

In order to define your problem, you must create a new Python file called problem.py. This file needs to contain a class called Problem which is an implementation of pyrallelsa.Problem. In your implementation of problem, define your: * move method: This will mutate the state of the solution as it is annealing * energy method: This determines the energy (also known as fitness) of the current solution. Since we are talking in terms of annealing, lower energy is better! (We are aiming to minimize) * divide method: The implementation of the divide method is up to your choosing. By definition, the divide method should subdivide the solution space given by your problem_data into the given divisions deterministically.

And you're done defining your problem! That was easy wasn't it?

Packaging your Problem for Magellan

Once you have your problem.py defined (see traveling-sailor's problem.py if you need an example), all you need to do is either publish this in a git repository (traveling-sailor is the optimal example!) or serve this is a gzip archive.

Creating a job via the Web UI

• Navigate to the "Create a Job" page by clicking the link on the top-right of the homepage.
• Enter a descriptive indentifying name for the job, (eg. Traveling Sailor).
• Enter how many minutes of CPU time (not real time) you want the job to run for, (eg. 40).

• Enter a URL to a git repository or a downloadable tarball (.tar.gz). The following are all valid examples from traveling-sailor. The first two are valid links to a git repository and the last is a static tarball. git repositories are recommended as they can be more efficiently updated if cached on an agent.

  • git://github.com/mesos-magellan/traveling-sailor
  • https://github.com/mesos-magellan/traveling-sailor.git
  • https://github.com/mesos-magellan/traveling-sailor/archive/0.1.0.tar.gz

• Enter any additional data in JSON format you want to be passed on to your module. (Example for traveling-sailor at the end of this section).

• Press the "Create Job" button, you will then be forwarded to the "Job Details" page for your newly created job.

Module JSON data example for traveling-sailor:

{
"cities": {
   "Holmesville": [31.7036111, -82.3208333],
   "Jatipasir": [-8.2509, 113.9975],
   "Tapalinna": [-2.923, 119.1626],
   "Sahout el Ma": [16.9166667, -15.1666667],
   "Isanganaka": [-0.683333, 24.083333],
   "El Yerbanis": [29.45, -108.6],
   "Gun-ob": [9.6289, 124.0517],
   "Chak Seventy-five ML": [31.345362, 71.123454],
   "Bakous": [13.7363889, -16.6080556],
   "Metkow Maly": [50.05, 19.4]
},
"updates_enabled": false,
"start_city": "Bakous"
}