In EHCache, is there a way to implement some kind of a db listener where the cahce will auto update if the data is out of sync? (e.g as soon as the user requests for data, the cahce checks if the data is out of sync, if yes...updates itself and returns the data, if not...just return the data from the cache)If someone can point me which part of the specification highlights this use, that would be awesome!
The goal is to always provide the latest data to the user. So I am guessing a timed refresh mechanism will not do as the data can change anytime.
EHCAche is not mandatory to use in my case, so any mechanism that satisfies this will be most welcome...
Thanks!!
Answer
For EhCache this is what I believe you are looking for. If you would not like to do timed refresh (even though it is a simple solution), triggers or a message bus based update would be the way to go. You can perform some statistics and see update frequency once the triggering has been established and switch to a timed update with sufficient frequency to satisfy Nyquist.