Tips for debugging multiple Node.js processes
Here are some quick tips for debugging multiple node.js. I had some trouble debugging multiple processes early on, but I realized a couple things I want to note. Hopefully they can help!
Debugging mulitple node processes
I like running node processes with the
--debug flag. I know there are other ways (like using
node-debug app.js) but I found doing this was best for dealing with many processes, mostly because you can still use node-inspector or terminal without much issue. If you need extra info here might be a good spot to start.
It should look something like this:
node --debug file_to_debug.js
At this point you can debug via node-inspector or terminal.
Node-inspector can attach itself to different processes if needed by changing the port. All you have to do is run
node-inspector in another terminal window then go to
You can then change the debugging port to inspect different processes. Start from port 5858 and move 1 up for every process.
If you want to know what process you’re debugging you can find out by using adding a watch expression
Open another terminal window and run:
node debug localhost:<debugging port>
Then you can basic terminal commands once debugging:
repl - Open debugger’s repl for evaluation in debugging script’s context
c - Continue execution on a break point (
n - Step next
s - Step in
o - Step out
pause - Pause running code (like pause button in Developer Tools)
You can find all of the terminal commands at The Node.js Documentation for Debugger