“The cache key is the fluid part and the cache content is the fixed part. A given key should always return the same content. You never update the content after it’s been written and you never try to expire it either.”— David Heinemeier Hansson, signalvnoise.com
“The technique of nesting fragment caches to maximize cache hits is known as russian doll caching. By nesting fragment caches, it ensures that caches can be reused even when content changes. When a change occurs to the top-most fragment cache, only that cache must be expired. Every nested cache of th…”— Kevin Faustino, blog.remarkablelabs.com