How to use profilers with Meteor?

Question

My Meteor application, in server side (node process), is using much more CPU than would be acceptable, and I want to investigate it.

Two simultaneous clients are leading node to use 100% of CPU. It is probably related to a massive use of observers, but I need to investigate it further before changing the whole application.

So, what tool can I use to profile it? How to use it?

Answer 1

APM, Application Performance Monitoring, is a Meteor package + cloud service developed by Arunoda Susiripala of MeteorHacks fame. It's in beta right now, and it looks very promising:

From the Costly Calls tab, you can drill into methods and identify those that take longest:

This 1-minute tutorial video shows just this identification of costly methods, which is probably what you want.

More screenshots