[SPARK-14804][Graphx] Graph vertexRDD/EdgeRDD checkpoint results Clas…

[apivovarov]

EdgeRDD/VertexRDD wrap partitionsRDD
e.g. EdgeRDDImpl.checkpoint() calls partitionsRDD.checkpoint()
EdgeRDD/VertexRDD isCheckpointed() method should be implemented the same way - it should call partitionsRDD.isCheckpointed

Spark-shell test works:

import org.apache.spark.graphx._
val users = sc.parallelize(List((3L, "lucas"), (7L, "john"), (5L, "matt"), (2L, "kelly")))
val rel = sc.parallelize(List(Edge(3L, 7L, "collab"), Edge(5L, 3L, "advisor"), Edge(2L, 5L, "colleague"), Edge(5L, 7L, "pi")))
sc.setCheckpointDir("/tmp/check")


val g = Graph(users, rel)
g.checkpoint
g.vertices.collect
g.edges.collect
g.isCheckpointed // true
// try to collect EdgeRDD/VertexRDD again
g.vertices.collect // works
g.edges.collect  // works

[apivovarov]

Related PRs
#15396
#12576

[SparkQA]

Test build #3329 has finished for PR 15447 at commit b123b68.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds no public classes.

[felixcheung]

@apivovarov do we need this fix?