IBM Streams 4.2

Example 2: Explicit fusion of operators both inside and outside of a parallel region

In this example of user-defined parallelism, the Src operator is fused with both operators A and B, and their replicas. The Snk operator is in a PE by itself.

The parallel transformation replicates operators A and B. The Src operator is given a splitter to feed the two parallel channels. Fusion places the Src operator with all the siblings of operators A and B in the same PE. Threaded ports are inserted between the splitter output ports and the replicas of operator A. Fusion places the Snk operator into its own PE.

composite Comp2(input In; output B) {
  graph
    stream<Type> A = Functor(In) {}
    stream<Type> B = Functor(A) {}
}

composite Main2 {
  graph
    stream<Type> Src = Source() {
      config placement: partitionColocation(“SrcAB”);  
    }

    @parallel(width=2)
    stream<Type> Out = Comp2(Src) {
      config placement: partitionColocation(“SrcAB”); 
    }

    () as Snk = Sink(Out) {
      config placement: partitionIsolation;
    }
}

The Logical and Physical stream graphs for Example 2.