title: SLURM and python, nodes are allocated, but the code only runs on one node
body: <p>I have a 4*64 CPU cluster. I installed SLURM, and it seems to be working, as if i call <code>sbatch</code> i get the proper allocation and queue. However if i use more than 64 cores (so basically more than 1 node) it perfectly allocates the correct amount of nodes, but if i <code>ssh</code> into the allocated nodes i only see actual work in one of them. The rest just sits there doing nothing. </p>
  
  <p>My code is complex, and it uses <code>multiprocessing</code>. I call pools with like 300 workers, so i guess it should not be the problem.</p>
  
  <p>What i would like to achieve is to call <code>sbatch myscript.py</code> on like 200 cores, and SLURM should distribute my run on these 200 cores, not just allocate the correct amount of nodes but actually only use one.</p>
  
  <p>The header of my python script looks like this:</p>
  
  <pre><code>#!/usr/bin/python3
  
  #SBATCH --output=SLURM_%j.log
  #SBATCH --partition=part
  #SBATCH -n 200
  </code></pre>
  
  <p>and i call the script with <code>sbatch myscript.py</code>.</p>