Maximum file limit has been reached :

Many times we get an error called the maximum number of files that can be opened has reach the limit, you can fix the issue as ;
In order to resolve this, you will have to login as a root on your server and edit the file called /etc/sysctl.conf

vi /etc/sysctl.conf

Add the line there as

fs.file-max = 22992

Save and exit from the file.

In order to apply these changes run the command called

# sysctl -p

This will increase the maximum number of open files for your system.