file descriptor leak in java program : too many open files

Question

I have a program which suffer from file descriptor increasing. I see when I execute the command ls -l /proc/5969/fd where 5969 is the pid of the java program the number of file descriptor continuously increasing. but I am unable to open one of those files decriptors to see what file remains open : here is an example of the listing :

lrwx------ 1 root root 64 oct 24 16:08 52295 -> socket:[2577706264]
lrwx------ 1 root root 64 oct 24 16:08 52296 -> socket:[2579543392]
lrwx------ 1 root root 64 oct 24 16:08 52297 -> socket:[2578760962]

Please help me finding a way to solve this file descriptor leak in knowing what files remains open and increase the file descriptor number.

Answer 1

Well, from a quick observation, you are using file descriptors on sockets, not files

In UNIX, both files and sockets use file descriptors, and so you have a problem where you are not closing sockets that you open.

As a result, you are not leaving a file open but are actually leaving port numbers locked from use by other programs.

Answer 2

Try

# lsof -p <pid>

will list all 'files' open by process id, may show you the ip/port the socket was bound to. If your program is client side, youre probably getting disconnected by TCP RST and not cleaning up the file descriptor properly.