Does Rails automatically set an EXPIRE attribute on keys when working
Redis, or will an old key sit there forever if it’s never manually
out? This is mostly a concern when using ActiveModel’s “cache_key”:
<%= cache @post do %>
The cache-key will be something like views/posts/744-20120613070958 .
the post is updated, and therefore gets a new cache-key, what happens to
the old one? Will it just sit there forever? Do I need to add an
expires_in option to every cache call, just to make sure it gets
up every once in a while?
<%= cache @post, expires_in: 1.month do %>