I have a Drupal with the majority of users logged
Approximately 25,000 pageviews per day.
Two front and two backend servers.
APC and Memcached installed.
Authcache for authenticated users.
Some 5,000 nodes and 20,000 reviews, about 20 types of content.
Approximately 100 modules.
The loading time of the web for a single user is about 3-5 seconds, but for 100 concurrent users are more than one minute.
What could be done?
Thank you very much.