[FLINK-3589] Allow setting Operator parallelism to default value

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 1.1.0
• Fix Version/s: 1.1.0
• Assignee: Greg Hogan
• Reporter: Greg Hogan
• Created: 08/Mar/16 13:33
• Updated: 02/Oct/19 17:49
• Resolved: 13/Apr/16 16:14

Description

User's can override the parallelism for a single operator by calling Operator.setParallelism, which accepts a positive value. Operator uses -1 to indicate default parallelism. It would be nice to name and accept this default value.

This would enable user algorithms to allow configurable parallelism while still chaining operator methods.

For example, currently:

	private int parallelism;
	...
	public void setParallelism(int parallelism) {
		this.parallelism = parallelism;
	}
	...
		MapOperator<Edge<K,LongValue>, Edge<K,IntValue>> newEdges = edges
			.map(new MyMapFunction<K>())
				.name("My map function");

		if (parallelism > 0) {
			newEdges.setParallelism(parallelism);
		}

Could be simplified to:

	private int parallelism = Operator.DEFAULT_PARALLELISM;
	...
	public void setParallelism(int parallelism) {
		this.parallelism = parallelism;
	}
	...
		DataSet<Edge<K,IntValue>> newEdges = edges
			.map(new MyMapFunction<K>())
			.setParallelism(parallelism)
				.name("My map function");

Issue Links

• is depended upon by: FLINK-2909 Gelly Graph Generators
• links to: GitHub Pull Request #1778