Node EADDRINUSE (Address Already in Use) Error
Every once in a while my MacBook Pro freaks out and a process goes rogue. This oftentimes happens when I'm working on the excellent debugger.html project; I attempt to start the server side of the debugger and suddenly I'm hit with an error that resembles the following, leading to the process not starting from that time forward:
Error: listen EADDRINUSE 0.0.0.0:9000
at Object._errnoException (util.js:1026:11)
at _exceptionWithHostPort (util.js:1049:20)
at Server.setupListenHandle [as _listen2] (net.js:1343:14)
at listenInCluster (net.js:1391:12)
at doListen (net.js:1500:7)
at _combinedTickCallback (internal/process/next_tick.js:141:11)
at process._tickCallback (internal/process/next_tick.js:180:9)
at Function.Module.runMain (module.js:667:11)
at startup (bootstrap_node.js:201:16)
at bootstrap_node.js:626:3
The best way to fix this issue is by killing the Node.js process that's running for the rogue task. Start by finding a listing of all of the node processes:
ps aux | grep node
You'll see a listing similar to this:
davidwalsh 12413 0.0 0.0 2592088 3888 ?? S 7:38PM 0:20.45 /Users/davidwalsh/Projects/debugger.html/node_modules/flow-bin/flow-osx-v0.52.0/flow davidwalsh 12412 0.0 0.0 29739356 2372 ?? S 7:38PM 0:00.12 /Users/davidwalsh/Projects/debugger.html/node_modules/flow-bin/flow-osx-v0.52.0/flow davidwalsh 12411 0.0 0.0 29732188 2372 ?? S 7:38PM 0:00.07 /Users/davidwalsh/Projects/debugger.html/node_modules/flow-bin/flow-osx-v0.52.0/flow davidwalsh 12410 0.0 0.0 29732188 2372 ?? S 7:38PM 0:00.07 /Users/davidwalsh/Projects/debugger.html/node_modules/flow-bin/flow-osx-v0.52.0/flow davidwalsh 12409 0.0 0.0 29731164 2372 ?? S 7:38PM 0:00.06 /Users/davidwalsh/Projects/debugger.html/node_modules/flow-bin/flow-osx-v0.52.0/flow
When you identify the rogue process, use the kill command along with the process number to remove it:
#kill -9 {process_number}
kill -9 12413
With the process killed you can now start up the server as normal!
There’s a trick I use for this in my watch scripts. Substitute ‘bin/www’ for whatever script Node is running:
kill -3 (ps aux | grep 'bin/www' | awk '{print $2}')And when you don’t know what process grabbed your port, you can find out via
You could further narrow down the list to only the processes listening on that port, by doing the following:
Then kill that process.
Much better solution, implemented internally at my employer:
Hash-derive port number from full path.
Rather than stick to localhost:9000 you’re getting a pseudo-random port unlikely to collide with any other session you’re running. You can debug two branches of the same codebase at once.
Being derived from the path, the port is sticky: you can restart as much as you wish.
This just saved me from having to nuke and reinstall
node_modules. Thaaaaaaanks!the command reply : ‘ps’ is not recognized as an internal or external command,
operable program or batch file.