The Cascading processing model is based on a "pipes and filters" metaphor. The developer uses the Cascading API to assemble pipelines that split, merge, group, or join streams of data while applying operations to each data record or groups of records.
In Cascading, we call a data record a Tuple, a pipeline a pipe assembly, and a series of Tuples passing through a pipe assembly is called a tuple stream.
Pipe assemblies are assembled independently from what data they will process. Before a pipe assembly can be executed, it must be bound to data sources and data sinks, called Taps. The process of binding pipe assemblies to sources and sinks results in a Flow. Flows can be executed on a data cluster like Hadoop.
Finally, many Flows can be grouped together and executed as a single process. If one Flow depends on the output of another Flow, it will not be executed until all its data dependencies are satisfied. This collection of Flows is called a Cascade.
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