At the end of the documentation here https://github.com/nathanmarz/storm/wiki/Trident-tutorial#state it mentions:
State's are not required to hold onto state forever. For example, you could have an in-memory State implementation that only keeps the last X hours of data available and drops anything older. Take a look at the implementation of the Memcached integration<https://github.com/nathanmarz/trident-memcached/blob/master/src/jvm/trident/memcached/MemcachedState.java> for an example State implementation. How would I go about doing this ? In Trident I haven't found an easy way to store a state for a period of time, then flush it out to an external datastore. -- Raphael Hsieh
