a draft implementation of key-based cache expiration model proposed in DHH's article "How key-based cache expiration works" https://signalvnoise.com/posts/3113-how-key-based-cache-expiration-works

key-based cache expiration.md

Implementation

1. implement a #cache_key method for every model, as this:

def cache_key
  "#{self.class.model_name.cache_key}/#{id}-#{self[:updated_at].utc.to_s(:number)}"
end

2. update update_at field whenever the model or it's related models (through method such as touch) are changed.

Conclusion

So whenever the model's content is updated, #cache_key update as well, e.g. from 'Event/5-2016033110450' to 'Event/5-2016040125545'. When you ask for the cache, you do:

Rails.cache.find(@event.cache_key)

This will give you the newest copy of event.

Notes

• the #cache_key method is inspired by ActiveRecord's #cache_key method

FE will have to provide the key with timestamp in the request.