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HBase, mail # dev - Coprocessor Feature proposal


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Re: Coprocessor Feature proposal
Ted 2013-02-28, 14:27
Thanks for sharing.

You're welcome to contribute this extension to the community.

On Feb 28, 2013, at 4:10 AM, Julian Wissmann <[EMAIL PROTECTED]> wrote:

> Hi,
>
> for a research project I wrote a custom coprocessor, for which
> ultimately, I just extended AggregationClient and
> AggregateImplementation.
> I needed two additional input parameters, a Long timePeriod over which
> to aggregate and an int count to know how many aggregations to return,
> the return value being a ConcurrentMap. The advantage of going with
> this approach is, that for aggregations with a large count but small
> periods, I don't need to either sort the data on the client side again
> or do n aggregations resulting in n scans, but instead get the same
> result with just one scan per region, which is a lot faster.
>
> Right now, the code is a little messy, as it was implemented as a
> quick and dirty proof of concept. However if there is interest in
> having this ability in hbase, I'd be pleased to clean it up, port it
> to head and release it into the wild.
> I realize, that not everyone has a data pattern as simple as ours and
> that this feature may not be overly useful to everyone. If anyone has
> an idea as to how to extend this functionality to make it more useful,
> let me know. I'm for example thinking about maybe having a more
> generic approach with some sort of Filter or something along the lines
> in order to not just being able to sort this for time periods but for
> key patterns also.
>
> Regards
> Julian