Sets the number of emitted values before a chunk is send to the reducers.
If your emitted values are big, you might want to change this to a lower value. If you want
to better balance your work, you might want to change this to a higher value.
A value of 0 means immediate transmission, but remember that low values mean higher traffic
A very high value might cause an OutOfMemoryError to occur if emitted values do not fit into
heap memory before being sent to reducers. To prevent this, you might want to use a combiner
to pre-reduce values on mapping nodes.
Set to true if statistics (for example, about processed entries)
should be transmitted to the job emitter, false otherwise. This might be used to show any kind of progress to
users inside of UI systems, but this produces additional traffic. If statistics are not needed, you might
want to deactivate this.
Sets how the map reduce framework will react on topology
changes while executing a job.
Currently only CANCEL_RUNNING_OPERATION is fully supported; it throws an exception to
the job emitter (throws com.hazelcast.mapreduce.TopologyChangedException).