I attended HTTP’s Best-Kept Secret: Caching with Ryan Tomayko for the early morning session. Ryan gave a brief overview of different types of HTTP caching (client, shared proxy and gateway), eventually focusing on the server-side gateway caching. This form of caching still sends data over the wire, but allows you to avoid hitting Rails entirely, or else – using something like ETags – allows you to minimize the amount of work done within Rails to generate the content. It sounds like HTTP caching in its current form is still a bit awkward to handle when the content of the response varies based on session state, e.g., whether or not the user is logged in.

Mid morning session found me at When to Tell Your Kids About Presentation Caching with Matthew Deiters. This covered some of the same material as the previous caching talk, but Matthew focused more on minimizing the amount of data sent over the wire. In addition to client-side caching, he covered some general tips on reducing the size of the server responses. Tips included reducing the number of resources (e.g., use Rails’ asset caching functionality to condense multiple javascript/CSS files into fewer [but larger] files) and reducing the size of resources through minification (obfuscation) and compression (e.g., Apache’s mod_deflate).

My late morning session was It’s Not Always Sunny in the Clouds: Lessons Learned with Mike Subelsky. Mike described some of the surprises and challenges he encountered over the past year working with Amazon EC2. He’s still a fan of the power and convenience introduced by cloud computing, but he’s developed a healthy respect for the complications and expenses it introduces over the old tangible, colocated server route. Turnkey provisioning rocks, but it involves a lot of work.