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arraysscalaapache-sparkspark-graphx

Spark GraphX - How to pass and array to to filter graph edges?

I am using Scala on Spark 2.1.0 GraphX. I have an array as shown below:

scala> TEMP1Vertex.take(5)
res46: Array[org.apache.spark.graphx.VertexId] = Array(-1895512637, -1745667420, -1448961741, -1352361520, -1286348803)

If I had to filter the edge table for a single value, let's say for soruce ID -1895512637

val TEMP1Edge = graph.edges.filter { case Edge(src, dst, prop) => src == -1895512637}

scala> TEMP1Edge.take(5)
res52: Array[org.apache.spark.graphx.Edge[Int]] = Array(Edge(-1895512637,-2105158920,89), Edge(-1895512637,-2020727043,3), Edge(-1895512637,-1963423298,449), Edge(-1895512637,-1855207100,214), Edge(-1895512637,-1852287689,339))

scala> TEMP1Edge.count
17/04/03 10:20:31 WARN Executor: 1 block locks were not released by TID = 1436:[rdd_36_2]
res53: Long = 126

But when I pass an array which contains a set of unique source IDs, the code runs successfully but it doesn't return any values as shown below:

scala> val TEMP1Edge = graph.edges.filter { case Edge(src, dst, prop) => src == TEMP1Vertex}
TEMP1Edge: org.apache.spark.rdd.RDD[org.apache.spark.graphx.Edge[Int]] = MapPartitionsRDD[929] at filter at <console>:56

scala> TEMP1Edge.take(5)
17/04/03 10:29:07 WARN Executor: 1 block locks were not released by TID = 1471:
[rdd_36_5]
res60: Array[org.apache.spark.graphx.Edge[Int]] = Array()

scala> TEMP1Edge.count
17/04/03 10:29:10 WARN Executor: 1 block locks were not released by TID = 1477:
[rdd_36_5]
res61: Long = 0
Solution

  • I suppose that TEMP1Vertex is of type Array[VertexId], so I think that your code should be like:

    val TEMP1Edge = graph.edges.filter { 
  case Edge(src, _, _) => TEMP1Vertex.contains(src) 
}