How key-based cache expiration works

https://signalvnoise.com/posts/3113-how-key-based-cache-expiration-works

1. The cache key is fluid part and the cache content is the fixed part
2. key is calculated from the content
3. when key changes, simply write the new content to new key
4. will generate a lot of cache garbage => don’t care => Memcached will automatically evict the oldest keys first when it runs out of space
5. You deal with dependency structure by tying the model object together on updates
6. The caching itself then happens in the views based on partials rendering the objects in question