[FLINK-2857] Gelly API improvements

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.10.0
• Component/s: Library / Graph Processing (Gelly)
• Assignee: Vasia Kalavri
• Reporter: Vasia Kalavri
• Created: 15/Oct/15 12:14
• Updated: 19/Oct/15 16:08
• Resolved: 19/Oct/15 16:08

Description

During the Flink Forward Gelly School training, I got some really valuable feedback from participants on what they found hard to grasp or non-intuitive in the API.

Based on that, I propose we make the following improvements:

• rename the mapper in creation methods to VertexInitializer, so that its purpose is easier to understand.
• add a fromTuple2DataSet method to easily create graphs from Tuple2 datasets, i.e. edges with no values.
• in joinWith* methods, it is hard to understand what are the parameters in the mapper and what will be the output. I suggest we flatten them, try to give intuitive names and improve the javadocs.
• in neighborhood methods, it is hard to understand what are the arguments of the EdgeFunction.iterateEdges and ReduceEdgesFunction.reduceEdges. Javadocs and parameter names could be improved here too.