Debugging Node.js processes with cluster.fork()

Question

I\'ve got some code that looks very much like the sample in the Cluster documentation at http://nodejs.org/docs/v0.6.0/api/cluster.html, to wit:

var cluster          


        

Answer 1

I already opened a ticket about this here: https://github.com/dannycoates/node-inspector/issues/130

Although it's not fixed yet, there's a workaround:

FWIW: The reason I suspect is that the node debugger needs to bind to the debug port (default: 5858). If you are using Cluster, I am guessing the master/controller binds first, and succeeds, causing the bind in the children/workers to fail. While a port can be supplied to node --debug=N there seems to be no easy way to do this when node is invoked within Cluster for the worker (it might be possible to programmatically set process.debug_port and then enable debugging, but I haven't got that working yet). Which leaves a bunch of options: 1) start node without the --debug option, and once it is running, find the pid for the worker process you want to debug/profile, and send it a USR1 signal to enable debugging. Another option is to write a wrapper for node that calls the real node binary with --debug set to a unique port each time. There are possibly options in Cluster that let you pass such as arg as well.