Too many open files, redhat 7.2 Server: cannot open shared libraries

Had an issue with Redhat 7.2  Linux Server, when I tried to login to the server this morning,I was getting an error " Unable to open shared libraries", turned out that the system had too many open files. I was able to login to the server as root but couldn't increase number of open files  through ulimit command. This is a production server and was not in a position to reboot it. Increased the limit using :   echo "10000"  > /proc/sys/fs/max-file and everything started working fine..