Apart from the count operation in a window, there are more operations that can be done on DStreams in conjunction with windowing. The following table captures the important transformations. All these transformations are acting on the selected window and return a DStream.
Transformation |
Description |
|
Returns DStreams computed in the window |
|
Returns the count of elements |
|
Returns one element by applying the aggregation function |
|
Returns one key/value pair per key after applying the aggregation function over multiple values per key |
|
Returns one key/count pair per key after applying the count of multiple values per key |
One of the most important steps of stream processing is the persisting of the...