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I have a big problem and that is that my company's production application which I unfortunately can't shutdown and restart ( I am unsure how, and I don't want to do any mistake) is spitting out a lot of exceptions on too many files open when trying to open a socket to read from an ftp server.

2013-01-02 16:19:03,222 ERROR [main] software.background.Program({225}) - Exception during ftp transfer
someclasses.ftp.FtpException: Could not create connection to xxxx
    at someclasses.communication.ftp.FtpImpl.connect(
    at Program.doExecute(
    at Program.main(
Caused by: Too many open files
    at someclasses.Ftp.connect(

I understand that the per application limit of open files / sockets and so on is reached. Is there any way to increase this maximum for the time being without closing the application? I have run the command ulimit and it states unlimited. I've tried to check how many connections it has open with the lsof -p PID command but it states "command not found".

Would be very glad if someone could help me find another similar effect that lsof has (I think it's a red hat machine) and advice for how to fix this temporary? The most pleasant solution to this would be to increase the files / sockets the application could open. This is just a plain java application.

Thanks in advance!

EDIT another solution would be if there were any command where I could look up how this program was run from the beginning with all the eventual flags. Then I maybe could restart it with success. This is a legacy app.

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migrated from Jan 2 '13 at 20:02

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to look up the full command lines for running apps use "ps -FA" – Steve Perkson Jan 2 '13 at 15:55
Thanks for the comment, I will probably use this if changing the ulimit -n to 2048 instead of 1024 won't fix it. changed it to the nofile configuration displayed in the link. You think it'll work? – cubsink Jan 2 '13 at 16:03
Running out of file descriptor also could be hint that your app is leaking file descriptors: missing to close them if not used anymore. If this is the case, increasing the number of available file descriptors won't help in the long. – alk Jan 2 '13 at 16:11
can you check /proc/sys/fs/file-max – JoG Jan 2 '13 at 16:27
@JoG That is a system maximum. – Peter Lawrey Jan 2 '13 at 16:29
up vote 1 down vote accepted

It all ended with a restart of the application. I changed the ulimit -n to 2048 and reloaded the config. However, all processes inherited the old config and the application had to be restarted.

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