The aforementioned killall -9 node
, suggested by Patrick works as expected and solves the problem but you may want to read the edit part of this very answer about why kill -9
may not be the best way to do it.
On top of that you might want to target a single process rather than blindly killing all active processes.
In that case, first get the process ID (PID) of the process running on that port (say 8888):
lsof -i tcp:8888
This will return something like:
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
node 57385 You 11u IPv6 0xac745b2749fd2be3 0t0 TCP *:ddi-tcp-1 (LISTEN)
Then just do (ps - actually do not. Please keep reading below):
kill -9 57385
You can read a bit more about this here.
EDIT: I was reading on a fairly related topic today and stumbled upon this interesting thread on why should i not kill -9
a process.
Generally, you should use kill -15 before kill -9 to give the target process a chance to clean up after itself. (Processes can't catch or ignore SIGKILL, but they can and often do catch SIGTERM.) If you don't give the process a chance to finish what it's doing and clean up, it may leave corrupted files (or other state) around that it won't be able to understand once restarted.
So, as stated you should better kill the above process with:
kill -15 57385
EDIT 2: As noted in a comment around here many times this error is a consequence of not exiting a process gracefully. That means, a lot of people exit a node command (or any other) using CTRL+Z. The correct way of stopping a running process is issuing the CTRL+C command which performs a clean exit.
Exiting a process the right way will free up that port while shutting down. This will allow you to restart the process without going through the trouble of killing it yourself before being able to re-run it again.