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From Thai Ngo <baothai...@gmail.com>
Subject Re: Trigger for Accumulo table
Date Mon, 07 Dec 2015 03:48:44 GMT
Christopher,

This is interesting! Could you please give me more details about this?

Thanks,
Thai

On Thu, Dec 3, 2015 at 12:17 PM, Christopher <ctubbsii@apache.org> wrote:

> You could also implement a constraint to notify an external system when a
> row is updated.
>
> On Wed, Dec 2, 2015, 22:54 Josh Elser <josh.elser@gmail.com> wrote:
>
>> oops :)
>>
>> [1] http://fluo.io/
>>
>> Josh Elser wrote:
>> > Hi Thai,
>> >
>> > There is no out-of-the-box feature provided with Accumulo that does what
>> > you're asking for. Accumulo doesn't provide any functionality to push
>> > notifications to other systems. You could potentially maintain other
>> > tables/columns in which you maintain the last time a row was updated,
>> > but the onus is on your "other services" to read the table to find out
>> > when a change occurred (which is probably not scalable at "real time").
>> >
>> > There are other systems you could likely leverage to solve this,
>> > depending on the durability and scalability that your application needs.
>> >
>> > For a system "close" to Accumulo, you could take a look at Fluo [1]
>> > which is an implementation of Google's "Percolator" system. This is a
>> > system based on throughput rather than low-latency, so it may not be a
>> > good fit for your needs. There are probably other systems in the Apache
>> > ecosystem (Kafka, Storm, Flink or Spark Streaming maybe?) that are be
>> > helpful to your problem. I'm not an expert on these to recommend on (nor
>> > do I think I understand your entire architecture well enough).
>> >
>> > Thai Ngo wrote:
>> >> Hi list,
>> >>
>> >> I have a use-case when existing rows in a table will be updated by an
>> >> internal service. Data in a row of this table is composed of 2 parts:
>> >> 1st part - immutable and the 2nd one - will be updated (filled in) a
>> >> little later.
>> >>
>> >> Currently, I have a need of knowing when and which rows will be updated
>> >> in the table so that other services will be wisely start consuming the
>> >> data. It will make more sense when I need to consume the data in near
>> >> realtime. So developing a notification function or simpler - a trigger
>> >> is what I really want to do now.
>> >>
>> >> I am curious to know if someone has done similar job or there are
>> >> features or APIs or best practices available for Accumulo so far. I'm
>> >> thinking of letting the internal service which updates the data notify
>> >> us whenever it updates the data.
>> >>
>> >> What do you think?
>> >>
>> >> Thanks,
>> >> Thai
>>
>

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