What is the concurrent processes limitation?
Shared plans are limited to 25 simultaneous processes per cPanel.
Note: Most sites will work perfectly with a 25 concurrent processes limit. Processes open and close so quickly that they hardly ever overlap.
If you are exceeding the limit, this could be caused by your mail client (Thunderbird, Mac mail, Outlook, etc.) checking for emails too many times in an hour. Per our mail policy, most of our servers have a limit of 30 POP3/IMAP checks per hour per IP address. Once this is hit, the server stores the check as a process to be handled after the 30 checks reset. However, more requests from your mail client keep coming. Therefore, more and more processes are stored until they hit the 25 process limit and thereafter brings your site down with a 500 error message.
Here is what you need to do:
- Close the mail client right away to see the site load back up. Closing the client will clear all the processes.
- Open the client again and look for the setting on how often it is checking the server for more emails. Set this to no less than 10 minutes apart.
Apple/Mac users: On most Apple devices there is a function called “push” and when it is enabled, it keeps the connection to our server open and continually checks mail. Consequently, this creates many IMAP processes and eventually will conflict with our Terms of Service.
If you are still hitting the process limit, you either have too much traffic for a shared server, or you need to optimize your database (for faster queries). Please email email@example.com for a proper assessment.