Fetchers

#Fetchers of Spout

The Fetchers are responsible for data acquiring to push data thereafter into Storm topology. Every Fetcher pulls the data from some connected data source. It is expected that every data item should contain some value and a timestamp.

The Fetcher is responsible for forming the tuple from data item which then is pushed to the first bolt of the specific chosen data Storm topology.

How is Fetcher implemented and the functionality of Spout and Fetcher one can see at Figure 1.

Figure 1. Spout and Fetcher: Class view

//TODO: Interface code set