What is the biggest difference and concerns about OpenLitespeed (not premium Litespeed) and Apache?
About speed, security and management issues, what should newbies understand? This is not about web hosting service, I mean to install by myself? thank you
Instead of writing this out again, I'm going to quote and link to my previous answer:
As of 2021, some of the "improvements" that Litespeed has developed vs. Apache are more theoretical than practical, such as HTTP/3 support (UDP-only) which is not even widely supported:
https://wordpress.org/support/topic/litespeed-or-apache-for-wordpress/
The more "core" features of Litespeed are their PHP handler LSAPI (LSPHP) and server-level cache which they call LSCACHE (not to be confused with the WordPress plugin they also released separately). The benefit here is that the same vendor is coding all these things, which means they should work smoothly together and can follow a more accelerated development timeline, etc.
One of the biggest reasons that people assume Litespeed is "better" than Apache is because they don't realize Apache already supports multiple caching methods, but that is simply not advertised well by most web hosting companies who prefer making money from selling WordPress cache plugins, etc, or by calling their caching feature something ridiculous like "ABC HOSTING SUPER CACHE".
The other major reason is because Litespeed has invested considerable effort into "confusing" WordPress users especially by publishing dishonest benchmarks showing that Litespeed performance being much faster than both Apache and even Nginx -- dishonest because, they did things like disabling FastCGI Cache on the Nginx server to ensure it performed slower, among who knows what else.
In conclusion, most users should not be using OpenLitespeed in production at this point because it's brand new software and relatively unstable compared to Apache/Nginx.
Litespeed's aggressive marketing team is trying to get the word out, that's all.
And remember that many of the features in Litespeed (premium) are not available in OpenLitespeed... for example you must restart the server after any .htaccess changes. And of course, OLS also does not support open source PHP handlers like PHP-FPM, which is ironic... in fact, they have been actively discouraging users from trying to compile PHP-FPM on OLS servers, rather undermining their alleged "open source" project values.
I had hundreds of tests on my WordPress sites with dedicated server and created hosting. As far as I can see, currently NGINX is a fairly stable server, rarely encounters minor errors, followed by Apache. Regarding speed, when I tested the above servers with caching support, NGINX + FastCGI Cache was not the best speed, but it was the best for Web Vital on my xetaitot.com site, a WordPress site. With WooCommerce and many images. Next is Open LiteSpeed. If you are building your own Web server, I recommend using NGINX!
