Why is global object on server side released after some time?

I have a class in one javascript file communicator.js

let communicator = null;
getCommunicator = function () {
  if (!communicator) {
    Log.info("Creating new communicator...");
    communicator = new Communicator();
  return communicator;

In order to retrieve the Communicator object I call the getCommunicator()-function in many places in the code to get the same communicator every time, i.e. a singleton.

My intention is thus that, once created, the Communicator object should persist in the global scope forever.

However I have seen that after some inactivity time on my webappliaction, the next time getCommunicator() is called it seems that the reference is gone and it has to create a new.

So any ideas why this is happening? Am I creating the global variable incorrectly? Or does a object has a life time in node?

Are you creating this in a Meteor method? Be careful with let - it’s block-scoped.

Well, yeah its created first time when called in a Meteor method. But if I call the method several times in close time period it is not recreated. So solution would be to change it to var?

You have two issues.

  1. Using let scopes the singleton to the method, and …
  2. A method is associated with each client connection. So, you’ll get a singleton per client.

If you want a true singleton, you could run this as part of the general server code - just put the file in the server/ folder, for example.

I found out what it was.

  • First I already have the file located in the server/folder so thats not it.
  • let, when placed in the global scope is the same as var so thats also no issue.

I was using https://github.com/meteorhacks/cluster so I depending on which worker I was allocated, the Communicator was not allocated for that worker.

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