Open file limits can impact some high-resource applications. 

To check the number of files currently open by all processes in the system, run:

# lsof | wc -l

To check the number of files opened by all processes of a particular user, run the following command. Replace "root" with the username of the user in question.

# lsof -u root | wc -l

To check the maximum file limit of the current user, run:

# ulimit -n

Or to print a summary of all limits, run:

# ulimit -a 

Changing file limits

To adjust file limits, edit the limit.conf file:

# vim /etc/security/limits.conf

username            soft            nofile            65536
username            hard           nofile           100000

Save the file and check the new limit using below command.

# ulimit -n


soft limit, is the default max value you get when you login

hard limit, is the max value to which you can raise using the ulimit command