How would someone write something like Newrelic, is it low level code i.e. kernel?

Question

How would you go about writing something similiar in nature to newrelic? i.e. something that monitors a live application.

Is it simply listening to traffic going over certain ports and logging it, or is it kernel level c/c++ code to do this?

Looking for an overview of what's involved, sounds like an interesting application to write.

Answer 1

The basics of what New Relic does are fairly easy to get started with. But the deeper you go, the more complicated it gets. There's a reason New Relic employs a lot of developers and QA people.

For Ruby and Rails, you can read the source code of the agent (it's on github) that wraps your code. It will give you a good idea of what it's doing. Although the agent is pretty complex, there is even more complicated stuff going on in the server.

I can't really go into details, since I work at New Relic, but you will find a lot of technical details if you look around, since we've talked about it pretty openly in the past.