My Node app uses Mongo change streams, and the app runs 3+ instances in production (more eventually, so this will become more of an issue as it grows). So, when a change comes in the change stream functionality runs as many times as there are processes.

How to set things up so that the change stream only runs once?

Here's what I've got:

```
const options = { fullDocument: "updateLookup" };

const filter = [
  {
    $match: {
      $and: [
        { "updateDescription.updatedFields.sites": { $exists: true } },
        { operationType: "update" }
      ]
    }
  }
];

const sitesStream = Client.watch(sitesFilter, options);

// Start listening to site stream
sitesStream.on("change", async change => {
  console.log("in site change stream", change);
  console.log(
    "in site change stream, update desc",
    change.updateDescription
  );

  // Do work...
  console.log("site change stream done.");
  return;
});

```