title: PM2 NodeJS cluster - Should I consider synchronizing when using pm2
body: <p>My express server does a very simple work - saving the request url into a file (via fs.appendFile).</p>
  
  <p>I suppose it works fine when not using pm2, because it has only one process, so no other process/thread saving the same file at the same time.</p>
  
  <p>But when using pm2, I don't know if it will occur two processes write the same file at the same time? Thanks.</p>