Hi devs, I was working on (FLINK-1526) "Add Minimum Spanning Tree library method and example" issue. I've developed (Java) code that implements distributed Boruvka's algorithm in Gelly library. I've run several tests and it seems to work fine, although I didn't test it on extremely large input graphs yet, and I'm also trying to optimize my code. Particularly, I have two main issues:
1. Nested loops. I have to use nested loops, and I do not see the way to avoid them. As they are currently not supported, I'm using Bulk Iterations inside a "classic" while loop. I've included in attachment simple example MyNestedIterationExample that shows this issue. 2. For some reason I cannot create class that works with types with generic variables in Tuple2(or Tuple3), thus my code does not support generic types. I also included simple example MyTuple3Example. Here is the Exception I get: "Exception in thread "main" org.apache.flink.api.common.functions.InvalidTypesException: Type of TypeVariable 'EV' in 'class org.apache.flink.graph.examples.MyTuple3Example$InitializeEdges' could not be determined. This is most likely a type erasure problem. The type extraction currently supports types with generic variables only in cases where all variables in the return type can be deduced from the input type(s)." I would really appreciate if someone could explain me know how to avoid this Exception. Otherwise, I could submit my code for testing. Best regards, Olga Golovneva
