Understanding Storm Internals by Examples - Real-time Analytics with Storm and Cassandra - page 62

All grouping
All grouping is a kind of broadcaster grouping that can be used in situations where the
same message needs to be sent to all instances of the destination bolt. Here, each tuple is
sent to all the instances of the bolt.
This grouping should be used in very specific cases, for specific streams, where we want
the same information to be replicated to all bolt instances downstream. Let's take a use case
that has some information related to a country and its currency value and the bolts follow-
ing the bolt, which does need this information for some currency conversion. Now whenev-
er currency bolt has any changes, it uses all grouping to publish it to all the instances of the
following bolts:
Here we have a diagrammatic representation of all grouping, where all the tuples from Bolt
A are sent to all the instances of Bolt B .