Question

I have started a Node server through the plugin of an IDE. Unfortunately, I cannot use the IDE’s terminal. So I tried to run the script from the command line.

This is the problem – I am using the Express module and my app is listening some port (8080). When I start the app from the command line, it throws this error:

events.js:71
    throw arguments[1]; // Unhandled 'error' event
                   ^
Error: listen EADDRINUSE
    at errnoException (net.js:770:11)
    at HTTPServer.Server._listen2 (net.js:910:14)
    at listen (net.js:937:10)
    at HTTPServer.Server.listen (net.js:986:5)
    at Object.<anonymous> (C:\xampp\htdocs\node\chat\app.js:5:5)
    at Module._compile (module.js:449:26)
    at Object.Module._extensions..js (module.js:467:10)
    at Module.load (module.js:356:32)
    at Function.Module._load (module.js:312:12)
    at Module.runMain (module.js:492:10)

Even though I am not very sure what this error could be I assumed that it’s because the app is listening on a port which is already in use. So I did:

netstat -an

I can see

TCP    0.0.0.0:8080           0.0.0.0:0              LISTENING

It’s because the Node server is already started when I tried to start it from the IDE.

So I want to know, how can I stop all server instances? Also if you can tell me how to detect what’s running on a port and kill it.

Answer 1

Windows Machine:

Need to kill a Node.js server, and you don’t have any other Node processes running, you can tell your machine to kill all processes named node.exe. That would look like this:

taskkill /im node.exe

And if the processes still persist, you can force the processes to terminate by adding the /f flag:

taskkill /f /im node.exe

If you need more fine-grained control and need to only kill a server that is running on a specific port, you can use netstat to find the process ID, then send a kill signal to it. So in your case, where the port is 8080, you could run the following:

C:\>netstat -ano | find "LISTENING" | find "8080"

The fifth column of the output is the process ID:

  TCP    0.0.0.0:8080           0.0.0.0:0              LISTENING       14828
  TCP    [::]:8080              [::]:0                 LISTENING       14828

You could then kill the process with taskkill /pid 14828. If the process refuses to exit, then just add the /f (force) parameter to the command.

---

MacOS machine:

The process is almost identical. You could either kill all Node processes running on the machine:

killall node

Or also as alluded to in @jacob-groundwater’s answer below using lsof, you can find the PID of a process listening on a port (pass the -i flag and the port to significantly speed this up):

$ lsof -Pi :8080
COMMAND   PID      USER   FD   TYPE             DEVICE SIZE/OFF NODE NAME
node     1073    urname   22u  IPv6  bunchanumbershere      0t0  TCP *:8080 (LISTEN)

The process ID in this case is the number underneath the PID column, which you could then pass to the kill command:

$ kill 1073

If the process refuses to exit, then just use the -9 flag, which is a SIGTERM and cannot be ignored:

$ kill -9 1073

---

Linux machine:

Again, the process is almost identical. You could either kill all Node processes running on the machine (use -$SIGNAL if SIGKILL is insufficient):

killall node

Or also using netstat, you can find the PID of a process listening on a port:

$ netstat -nlp | grep :8080
tcp        0      0 0.0.0.0:8080         0.0.0.0:*                   LISTEN      1073/node

The process ID in this case is the number before the process name in the sixth column, which you could then pass to the kill command:

$ kill 1073

If the process refuses to exit, then just use the -9 flag, which is a SIGTERM and cannot be ignored:

$ kill -9 1073