CODEWITHSUNDEEP
node.jsprofile
Tremendus Apps
Tremendus Apps

Reputation: 1555

Possible to attach Node's built-in profiler to an existing process

I'm familiar with Node's build in CPU profiler:

NODE_ENV=production node --prof server.js

... but can the profiler be attached to a running process.

The problem I need to solve is that there is a lot of heavy lifting during start up on our IoT Gateway and I want to profile the CPU only AFTER the heavy lifting during steady state, so I want to attach it to the running process rather than monitor from start up as it will totally mis-represent my steady-state.

I am aware you can do this with the debugger, but I need to do it for the profiler.

Upvotes: 3

Views: 1693

Answers (1)

tenbits
tenbits

Reputation: 8008

You can use remote inspector

 NODE_ENV=production node --inspect-brk server.js

Now, go in chrome to chrome://inspect and launch NodeJS Inspector and resume the application

  1. Manually start the profiler from Profiler tab.
  2. You can start profiler within your code with console.profile() and console.profileEnd()

If you want to inspect remote server:

  1. Start the script with: NODE_ENV=production node --inspect=0.0.0.0:9229 server.js
  2. In chrome://inspect click Configure new Discover network targets and add the IP address and 9229 port of your server. Refersh the page, and then you will see your remote server to inspect.

Make sure to open the 9229 port on remote server firewall. If you can access only 22(ssh) then try to open ssh-tunel: ssh -L 9229:127.0.0.1:9229 some@myserver -N. Then you can start the server only with --inspect flag, without ip-binding.

Upvotes: 4

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