When possible it will do as much aggregation Storm-side so as to minimize amount it needs to interact with database. So if you do a persistent global count, for example, it will compute the count for the batch (in parallel), and then the task that finishes the global count will do a single get/update/put to the database.
On Tue, Jun 3, 2014 at 3:08 PM, Raphael Hsieh <[email protected]> wrote: > How does PersistentAggregate distribute the database calls across all the > worked nodes ? > Does it do the global aggregation then choose a single host to do a > multiget/multiput to the external db ? > > Thanks > -- > Raphael Hsieh > > > > -- Twitter: @nathanmarz http://nathanmarz.com
