Hi
I'm trying to count the occurrence of a key in a grouped table. But the
following code snippet [1] fails [2] when calling count() on a MemPipeline
in version 0.8.2+71-cdh4.6.0.
Am I using the API incorrectly or is this a bug?
Cheers,
-Kristoffer
[1]
PCollection<String> lines =
MemPipeline.typedCollectionOf(Writables.strings(), input);
lines.parallelDo(new DoFn<String, Pair<String, String>>() {
@Override
public void process(String input, Emitter<Pair<String, String>> emitter) {
emitter.emit(Pair.of(input, input));
}
}, tableOf(strings(), strings()))
.groupByKey()
.count();
[2]
java.lang.IllegalArgumentException: Key type must be of class WritableType
at org.apache.crunch.types.writable.Writables.tableOf(Writables.java:351)
at
org.apache.crunch.types.writable.WritableTypeFamily.tableOf(WritableTypeFamily.java:95)
at org.apache.crunch.lib.Aggregate.count(Aggregate.java:65)
at org.apache.crunch.lib.Aggregate.count(Aggregate.java:56)
at
org.apache.crunch.impl.mem.collect.MemCollection.count(MemCollection.java:230)
at
mapred.functions.FunctionsTest.testGroupActionCount(FunctionsTest.java:79)
