Reliability is one of the core architecture principle on which Flume was built on. To take care of failures, flume components can be arranged in a variety of fashion. In case of failures when transferring data from channel to sink, sink can be setup in a load balanced or failover fashion. For achieving this prerequisite is to configure a Sink Group. A Sink Group, as its name suggests, is a logical grouping of of sinks. The defined or these named group participates in load balancing or failover case.

Some of the aspects of a Sink Group which are worth noting down is as follows:

• A sink can only be associated with one Sink Group at a time.
• All sinks has their own default Sink Group where it belongs to.
• If not specified each sink belongs to this default Sink Group and it behaves as a pass through for events.
• The Sink Group can be deactivated at any point but deactivating it doesn't have any impact on the sinks participating in that Sink Group.
• In the Flume configuration, Sink Group is a top level element.