title: Node.js: How to serialize a large object with circular references
body: <p>I use Node.js and want to serialize a large javascript object to HDD. The object is basically a "hashmap" and only contains data, not functions. The object contains elements with circular references. </p>
  
  <p>This is an online application so the process should not block the main loop. In my use-case Non-blocking is much more important than speed (data is live in-memory data and is only load at startup, saves are for timed backups every X minutes and at shutdown/failure)</p>
  
  <p>What is the best way to do this? Pointers to libraries that do what I want are more than welcome.</p>