I want to build a health focused community similar to empowher.com and supportgroups.com. Both of these sites run on Drupal, but there is very little information available about how they were able to scale up these sites.
I have used Drupal for the last 5 years, but the site I have created are more for businesses where there are no logged in users. The site I want to create will have the following functionality:
1. Detailed User Profiles
2. User Blogs
3. Groups
I know Drupal has the functionality, but can it scale for authenticated users? I have found modules for everything that I want to do, but here I have concerns about Drupal's ability to scale for authenticated users. I have found the authcache module, and I will be using pressflow. There is also a case study where a similar site migrated away from Drupal to Yii. There were drastic performance improvements. The site is realself.com and here is the case study: http://erickennedy.org/Drupal-7-Reasons-to-Switch. Also, I looked at the information for onsugar on Drupal.org, and it seems like they had to hack Drupal to death to get it to perform. I know that people often reference Drupal.org to address questions like this, but what are the details behind how Drupal.org was made to scale?
Way in the future, the site needs to be able to handle about 5000 authenticated users at any one time.