title: Is it possible to get index of the slave process at the runtime?
body: <p>Suppose I run pm2 in cluster mode <code>pm2 start app.js -i 4</code>, Is it possible to get information about current number in the instances pool <strong>inside</strong> the app.js.</p>
  
  <p>I mean in the <code>app-0</code> it would be <code>0</code>, in the <code>app-1</code> it would be <code>1</code>, etc. I need to get this number at runtime.</p>
  
  <p>I didn't find any references in the docs.</p>