Invalidating space timestamp
We use memcached extensively throughout the White Label Dating platform, primarily for write-through data caching.
Cloudinary provides a secure and comprehensive API for easily uploading images from server-side code, directly from the browser or from a mobile application.
Due to the heavy customisation of each logged-in member's pages, we can only perform full-page caching on the visitor and search results pages; with people like Google now taking page load speed into consideration for search rankings, serving crawler-visible pages up quickly becomes even more important (if you could ever argue that there was anything more important than user experience when talking about load times). We're currently getting around a 60% hit rate for our view cache which, while not fantastic, is reasonable considering the number of variations for each page, based on site and query string parameters (as a comparison, we're getting 96.5% for the data cache).
However, it's exactly this number of variations which has recently been causing us trouble.
In our case, we chose to version our keys based on the epoch-translated timestamp of the last-modified date for the site in question.
We felt that this method had the best combination of costs and benefits for us: Everyone's invalidation technique will be different, and most people will use more than one depending on the type of data.