New site, new server structure
For many years now, we are using Drupal as our content management system. It has served us well and over some versions so far. As more visitors arrived, we had to enable different ways of caching and optimize the size of the pages, to keep the server load under control.
With the latest release, we again hit a limit on our server. Though the pages were cached, the apache server still had to call php, do some calculations and then server the site. So had to move one step further. We now use Varnish in front of our server. This allows us to serve the pages from the cache right away. To fully support the caching, we had to upgrade Drupal to the compatible Pressflow system. It is based on Drupal, but includes some optimizations for performance and caching issues present in Drupal.
With this new combination, we are able to serve regular pages really fast. When I use the developer tools of the Chrome browser, I see around 120 to 200 ms until the page html is loaded. The whole page including images is loaded and rendered in less than a second. That's really amazing. Now I am excited to see when we will have to upgrade the web site the next time...