Hi, I think Flink does in fact not drop the dangling parts. In streaming it is allowed to have dangling operators that are not sinks. They are executed and the output is just discarded.
Cheers, Aljoscha > On 08 Oct 2015, at 16:18, Matthias J. Sax <mj...@apache.org> wrote: > > Hi, > > I just hit a problem in Storm Compatibility: > https://issues.apache.org/jira/browse/FLINK-2837 > > If a bolt has multiple inputs, the topology is not translated correctly > into a Flink streaming program. The point is, that the Flink program can > be executed without an error, even if the assembled data flow has > dangling parts... > > For example: > > Source1 --+--+--> Bolt --> SinkBolt > | | > Source2 --+ | > | > Source3 -----+ > > Is translated to the following Flink program > > Source1 --> Bolt --> SinkBolt > > Source2 --> Bolt > > Source3 --> Bolt > > with Source2 and Source3 being added to the environment but not > connected correctly to the overall program because the Bolt is > instantiated three times and only a single bolt is connect to the sink. > It is clear, that Flink just drops the dangling parts, as it builds the > JobGraph starting from the sink and traversing backwards. I was just > wondering, if an error should actually occur. > > > -Matthias >
