Severe performance drop with MongoDB Change Streams

Question

I want to get real-time updates about MongoDB database changes in Node.js.

A single MongoDB change stream sends update notifications almost instantly. But when I ope

Answer 1

The default connection pool size in the Node.js client for MongoDB is 5. Since each change stream cursor opens a new connection, the connection pool needs to be at least as large as the number of cursors.

const mongoConnection = await MongoClient.connect(URL, {poolSize: 100});

(Thanks to MongoDB Inc. for investigating this issue.)