storm-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Cody A. Ray" <cody.a....@gmail.com>
Subject Re: PersistentAggregate
Date Wed, 28 May 2014 14:43:37 GMT
You may find this helpful to understanding persistantAggregate works
internally.

http://svendvanderveken.wordpress.com/2013/07/30/scalable-real-time-state-update-with-storm/

-Cody


On Tue, May 27, 2014 at 1:53 PM, Danijel Schiavuzzi
<danijel@schiavuzzi.com>wrote:

> The aggregations are done by Storm. persistentAggregate provides only a
> means to access the datastore to get the current aggregate for the
> specified key (using the IBackingMap's multiGet() implementation),
> provide that aggregate as the input to the Aggregator implementation along
> with other same-keyed tuples in the current batch (the
> groupBy/GroupedStream), and persist it back to the database using
> multiPut().
>
>
> On Tuesday, May 27, 2014, Raphael Hsieh <raffihsieh@gmail.com> wrote:
>
>> From my understanding, PersistentAggregate should first aggregate the
>> batch, then once the batch has finished aggregating, send it to whatever
>> datastore is specified.
>>
>> Is this the case ? Or will the Persistent Aggregate use the external
>> datastore in order to do the aggregations ?
>>
>> --
>> Raphael Hsieh
>>
>>
>>
>
>
> --
> Danijel Schiavuzzi
>
> E: danijel@schiavuzzi.com
> W: www.schiavuzzi.com
> T: +385989035562
> Skype: danijels7
>



-- 
Cody A. Ray, LEED AP
cody.a.ray@gmail.com
215.501.7891

Mime
View raw message