So you do agree that the user should handle such cases or Hama should implement
different methods to keep track of previous states?
On 23 Ιαν 2014, at 11:31 π.μ., Edward J. Yoon <edwardy...@apache.org> wrote:
> Yes, AbsDiffAggregator. I've uploaded a patch.
>
> On Thu, Jan 23, 2014 at 7:21 PM, Anastasis Andronidis
> <andronat_...@hotmail.com> wrote:
>> Hello,
>>
>> sorry I am a little bit confused.
>> if I understand correctly, the problem is that we don't keep the value of
>> the previous superstep? Isn't this something that the user should implement
>> on his own?
>>
>> I'll take as an example the AbsDiffAggregator:
>>
>> This aggregator is taking as an input, the (old value of the vertex) - (the
>> current value) and then it sums everything across all vertices. Isn't this
>> the same as making the diff inside the vertex and then sending the output to
>> a sum aggregator?
>>
>> (by the user in Vertex class)
>>
>> --- in the beginning of the code ---
>> startV = this.getValue();
>>
>> /* Code run */
>>
>> this.aggregate("sum_aggr", startV - this.getValue());
>>
>> If I am correct, I think that we should document this kind of behavior, so
>> the users can use it. I said that I will handle the documentation on the
>> wiki for the aggregators, I have it on schedule for this weekend.
>>
>> Cheers,
>> Anastasis
>>
>> On 23 Ιαν 2014, at 2:30 π.μ., Edward J. Yoon <edwardy...@apache.org> wrote:
>>
>>> I found a bug in aggregator.
>>>
>>> In parseMessages, you calls masterAggregation() method. Do you think
>>> everything is OK?
>>>
>>> /**
>>> * Method to let the custom master aggregator read messages from peers and
>>> * aggregate a value.
>>> */
>>> @SuppressWarnings("unchecked")
>>> public void masterAggregation(Text name, Writable value) {
>>> String nameIdx = name.toString().split(";", 2)[1];
>>> this.Aggregators.get(nameIdx).aggregate(null, value);
>>>
>>> // When it's time to send the values, we can see which aggregators are
>>> used.
>>> this.aggregatorsUsed.add(nameIdx);
>>> }
>>>
>>> The aggregated value will be always the last value.
>>>
>>> Like our old code,
>>>
>>> getAggregationRunner().aggregateVertex(lastValue, vertex);
>>>
>>> You should aggregates all values.
>>>
>>> --
>>> Best Regards, Edward J. Yoon
>>> @eddieyoon
>>>
>>
>
>
>
> --
> Best Regards, Edward J. Yoon
> @eddieyoon
>
