I don't understand this part of the code. Can you please explain?
class ReflexivePairMasterCompute extends DefaultMasterCompute {
registerPersistentAggregator[LongArrayListWriteable]("reflexive_edges",
classOf[LongArrayListAggregator])
registerPersistentAggregator[LongArrayListWriteable]("non_reflexive_edges",
classOf[LongArrayListAggregator]
}
What I would do:
Typically you extend DefaultMasterCompute and then override the initialize
method where you register all the aggregators that you want. Do it like
this.
class ReflexivePairMasterCompute extends DefaultMasterCompute {
@Override
public void initialize() throws InstantiationException,
IllegalAccessException {
registerPersistentAggregator("reflexive_edges",
LongArrayListAggregator.class);
registerPersistentAggregator("non_reflexive_edges",
LongArrayListAggregator.class);
}
}
On Mon, Nov 18, 2013 at 11:53 PM, Artie Pesh-Imam <[email protected]
> wrote:
> Hi all,
>
> Im trying to register a persistent aggregator and am getting a NPE:
> version: Giraph 1.0 running against hadoop 1
>
> java.lang.NullPointerException
> at
> org.apache.giraph.master.MasterCompute.registerPersistentAggregator(MasterCompute.java:152)
>
> class ReflexivePairMasterCompute extends DefaultMasterCompute {
> registerPersistentAggregator[LongArrayListWriteable]("reflexive_edges",
> classOf[LongArrayListAggregator])
>
> registerPersistentAggregator[LongArrayListWriteable]("non_reflexive_edges",
> classOf[LongArrayListAggregator]
> }
>
> Any ideas? It looks like it’s having issues with the following line, which
> leads me to wonder if I need to do something to init the graph state:
>
> return getGraphState().getGraphTaskManager().getMasterAggregatorUsage().
> registerPersistentAggregator(name, aggregatorClass);
>
>
> --
> Artie Pesh-Imam
> Software Engineer @ Tapad
> 201-253-9647
>
