There are situation the cpanel shows Entry Processes 20/20 (100%) and when you access website it shows error: ‘508 Resource limit is reached’
It is due to fault in entry processes.
What is considered an Entry Processes in cPanel
If you log into cPanel, you will see on the left hand side "Entry Processes" with a number.
An "Entry Process" is how many PHP scripts you have running at a single time. Our shared hosting has a limit of 20 PHP scripts at a single time.
Keep in mind an "Entry Process" only takes roughly a second to complete, therefore most people get it confused with how many visitors they can have on their website. A 20 limit Entry Process doesn't mean only 20 people can be on your website at once because the likelihood of all 20 people hitting your website at the exact same second would never happen.
We've seen an entry limit of 20 usually handle 80-100 visitors on your website at a time on same process or script. If you have a low traffic website but are constantly at 20 Entry Processes, it means something is wrong with your scripts and they are hanging around longer then they should.
We can check the long running PHP scripts using below command in Terminal:
ps --sort etime -A -o etime,pid,user,args | grep php | grep -vE 'php-fpm|\-\-mode daemon|grep'
You will see a result something like:
00:11 552452 virt23422 lsphp:1671/domains/tompai.pro/public_html/index.php
The second number here is the PID or process ID.
To see all processes in live mode, type in:
To exit from live mode, just type q.
Now we can start killing the processes using below command:
kill -9 552452 (here 552452 is the process ID which can get from the ps command result)
After killing two long running processes, your website will start working.