Ask HN: Best way for monitoring Node.js in production?

Hi,

What do you use to monitor node.js processes in production? Assume that I would like to use nginx as my load balancer and some tool to keep node.js application running, like: forever or pm2. I would like to display data like heap, cpu usage, errors, maybe event loop state in realtime by web user interface remotely.

The best option would be to use some open source tool, but I am also thinking about using some proprietary solution.

What do you think?

Best, Wiktor