How do I remove a CLOSE_WAIT socket connection

linux sockets
Dilletante picture Dilletante · Apr 9, 2013 · Viewed 312.2k times · Source

I have written a small program that interacts with a server on a specific port. The program works fine, but:

Once the program terminated unexpectedly, and ever since that socket connection is shown in CLOSE_WAIT state. If I try to run a program it hangs and I have to force it close, which accumulates even more CLOSE_WAIT socket connections.

Is there a way to flush these connections?

Answer

derobert picture derobert · Apr 9, 2013

CLOSE_WAIT means your program is still running, and hasn't closed the socket (and the kernel is waiting for it to do so). Add -p to netstat to get the pid, and then kill it more forcefully (with SIGKILL if needed). That should get rid of your CLOSE_WAIT sockets. You can also use ps to find the pid.

SO_REUSEADDR is for servers and TIME_WAIT sockets, so doesn't apply here.

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