Chapter 3: Watermarks
Watermark
"The watermark is a monotonically increasing timestamp of the oldest work not yet completed."
Watermarks assert that all earlier events have (probably) arrived.
Perfect Watermark
When stream elements are in order (or in order by key), we can assert that a watermark at some time is accurate.
Heuristic Watermark
Watermarks determined by a set of rules to capture potentially late data from heterogeneous sources.
An Example
Propagation
Propagation Example
Percentile Watermarks
Processing time Watermarks
Flink Watermark Model
Flink Kafka Example
Fin
Chapter 3: Watermarks
By Jowanza Joseph
