I need some advice, I currently have a site that produces about 10,000 users at the same time. I currently use php, smarty3 (with its cache system), nginx and memcached. I would like to integrate an even stronger cache system for full page cache. I was thinking of using redis, do you think it is okay or do I go with varnish?
However, calculating that varnish is not officially supported by plesk.
What do you recommend?
Thank you
Varnish will probably yield the best performance and offer the most flexibility when it comes to tailoring the behavior of the cache to the needs of your application.
While Redis is an excellent distributed cache that is more feature-rich than Memcached, Redis is used as a caching data store for internal objects or to offload your MySQL database.
Varnish will actually sit in front of the application and cache the full output coming from your Nginx server. While Nginx has decent page caching capabilities out of the box, Varnish has more flexibility in terms of caching and granular cache invalidation. The logging tools of Varnish are also superior.
As mentioned in one of the previous comments, you can definitely combine Redis & Varnish. Just make sure you have tight control over your invalidation strategy and purge the right caches at the right time.