Number of visitors on website – An Entry Process should not be confused with the number of visitors you can have on your website as it takes just fractions of a second to complete.
For Eg. if we have restrict 25 entry processes that doesn’t mean that only 25 people can visit your website at a time. It’s because there is very rare possibility of 25 people browsing your website at the same fraction of a second.
When a visitor browses any web page of your website, the web server would start serving the request. While this request is being served, it will use one entry process.
Once this request has been served, the web server would no longer use an entry process and the entry process count would get decreased by 1.
Please note that cron jobs, shell scripts and other commands also use entry process for the duration of the time they are running.
Why such restrictions – Entry process limitations to ensure that no single user consumes all server resources and to prevent DDoS attacks against the web server.
Entry process will limit the number of concurrent connections to web server, thus preventing our server against malicious traffic.
When you use all allotted entry processes (25), new visitors would experience a 508 error.