Program with two BroadcastVars causes CompilerException

The following CompilerException is raised by

```
eu.stratosphere.compiler.CompilerException:
No plan meeting the requirements could be created @ GroupReduce (eu.stratosphere.example.java.clustering.Prog$IdentityReduce) (1:null).
Most likely reason: Too restrictive plan hints.
```

this program.

```java
public class Prog {

@SuppressWarnings("unchecked")
public static void main(String[] args) throws Exception

{ final ExecutionEnvironment env = ExecutionEnvironment .getExecutionEnvironment(); DataSet<Integer> bc1 = env.fromElements(0); DataSet<Integer> bc2 = env.fromElements(0); DataSet<Tuple1<Integer>> data = env.fromElements( new Tuple1<Integer>(0), new Tuple1<Integer>(0)); DataSet<Tuple1<Integer>> data2 = data .flatMap(new IdentityMap()) .withBroadcastSet(bc1, "BC1"); DataSet<Tuple1<Integer>> data3 = data2 .groupBy(0) .reduceGroup(new IdentityReduce()) .withBroadcastSet(bc1, "BC1") .withBroadcastSet(bc2, "BC2"); data3 .flatMap(new IdentityMap()) .print(); data2 .flatMap(new IdentityMap()) .print(); env.setDegreeOfParallelism(1); env.execute("CustomALS"); }

public static final class IdentityMap extends
FlatMapFunction<Tuple1<Integer>, Tuple1<Integer>> {
@Override
public void flatMap(Tuple1<Integer> value,
Collector<Tuple1<Integer>> out)

{ out.collect(value); }

}

public static final class IdentityReduce extends
GroupReduceFunction<Tuple1<Integer>, Tuple1<Integer>> {
@Override
public void reduce(Iterator<Tuple1<Integer>> values,
Collector<Tuple1<Integer>> out) {
while (values.hasNext())

{ out.collect(values.next()); }

}
}
}

```

---------------- Imported from GitHub ----------------
Url: https://github.com/stratosphere/stratosphere/issues/880
Created by: fhueske
Labels: bug, optimizer,
Milestone: Release 0.5.1
Created at: Wed May 28 15:44:15 CEST 2014
State: open