Node.js app has periodic slowness and/or timeouts (does not accept incoming requests)

Question

This problem is killing the stability of my production servers.

To recap, the basic idea is that my node server(s) sometimes intermittently slow down, sometimes resultin

Answer 1

My guess is Mongoose. If you are storing large payloads in Mongo, Mongoose can be pretty slow due to how it builds the Mongoose objects. See https://github.com/LearnBoost/mongoose/issues/950 for more details on the problem. If this is the problem you wouldn't see it in Mongo itself since the query returns quickly, but object instantiation could take 75x the query time.

Try setting up timers around (process.hrtime()) before and after you the Mongoose objects are being created to see if that might be the problem. If this is the problem, I would switch to using the node Mongo driver directly instead of going through Mongoose.