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Posted to user@accumulo.apache.org by Geoffry Roberts <th...@gmail.com> on 2017/12/20 16:43:33 UTC

Triggers or their equivalent

I have need of a trigger mechanism in Accumulo.  My first impulse was to
use an iterator, but the documentation advised against this.  I think I can
see why.

Is there a best practice way of accomplishing this?  Is there any plan to
add such functionality in the future?

-- 
There are ways and there are ways,

Geoffry Roberts

Re: Triggers or their equivalent

Posted by Geoffry Roberts <th...@gmail.com>.
I was un familiar with fluo. Its notifications might be what I need.

Thanks

On Wed, Dec 20, 2017 at 1:31 PM, Keith Turner <ke...@deenlo.com> wrote:

> On Wed, Dec 20, 2017 at 12:32 PM, Josh Elser <el...@apache.org> wrote:
> > Accumulo doesn't provide any mechanism to build a traditional trigger
> like a
> > traditional RDBMS or HBase. Can you share more details about what exactly
> > you want this trigger to do? It's possible we can suggest an alternate
> > approach which would fit naturally.
> >
> > If your trigger is causing other updates to Accumulo or creating some
> remote
> > I/O operation, the general recommendation would be to handle this at a
> > higher-level instead of in Accumulo itself. For generating "follow-on"
> > updates in Accumulo from a single update, Apache Fluo is a good starting
> > point. There are many other tools which you could use to build your own
> kind
> > of system, but this is very dependent on your actual requirements.
>
> Fluo is a good solution if you would like to join existing data with
> new data and update a query table based on the results of the joins.
> If no joins are required, something like Kafka may be a good solution.
> Insert new data into Kafka and have a consumer group that inserts into
> Accumulo.  Have other consumer groups for the actions you want to
> Accumulo triggers to take.
>
>
> >
> >
> > On 12/20/17 11:43 AM, Geoffry Roberts wrote:
> >>
> >> I have need of a trigger mechanism in Accumulo.  My first impulse was to
> >> use an iterator, but the documentation advised against this.  I think I
> can
> >> see why.
> >>
> >> Is there a best practice way of accomplishing this?  Is there any plan
> to
> >> add such functionality in the future?
> >>
> >> --
> >> There are ways and there are ways,
> >>
> >> Geoffry Roberts
>



-- 
There are ways and there are ways,

Geoffry Roberts

Re: Triggers or their equivalent

Posted by Keith Turner <ke...@deenlo.com>.
On Wed, Dec 20, 2017 at 12:32 PM, Josh Elser <el...@apache.org> wrote:
> Accumulo doesn't provide any mechanism to build a traditional trigger like a
> traditional RDBMS or HBase. Can you share more details about what exactly
> you want this trigger to do? It's possible we can suggest an alternate
> approach which would fit naturally.
>
> If your trigger is causing other updates to Accumulo or creating some remote
> I/O operation, the general recommendation would be to handle this at a
> higher-level instead of in Accumulo itself. For generating "follow-on"
> updates in Accumulo from a single update, Apache Fluo is a good starting
> point. There are many other tools which you could use to build your own kind
> of system, but this is very dependent on your actual requirements.

Fluo is a good solution if you would like to join existing data with
new data and update a query table based on the results of the joins.
If no joins are required, something like Kafka may be a good solution.
Insert new data into Kafka and have a consumer group that inserts into
Accumulo.  Have other consumer groups for the actions you want to
Accumulo triggers to take.


>
>
> On 12/20/17 11:43 AM, Geoffry Roberts wrote:
>>
>> I have need of a trigger mechanism in Accumulo.  My first impulse was to
>> use an iterator, but the documentation advised against this.  I think I can
>> see why.
>>
>> Is there a best practice way of accomplishing this?  Is there any plan to
>> add such functionality in the future?
>>
>> --
>> There are ways and there are ways,
>>
>> Geoffry Roberts

Re: Triggers or their equivalent

Posted by Josh Elser <el...@apache.org>.
Accumulo doesn't provide any mechanism to build a traditional trigger 
like a traditional RDBMS or HBase. Can you share more details about what 
exactly you want this trigger to do? It's possible we can suggest an 
alternate approach which would fit naturally.

If your trigger is causing other updates to Accumulo or creating some 
remote I/O operation, the general recommendation would be to handle this 
at a higher-level instead of in Accumulo itself. For generating 
"follow-on" updates in Accumulo from a single update, Apache Fluo is a 
good starting point. There are many other tools which you could use to 
build your own kind of system, but this is very dependent on your actual 
requirements.

On 12/20/17 11:43 AM, Geoffry Roberts wrote:
> I have need of a trigger mechanism in Accumulo.  My first impulse was to 
> use an iterator, but the documentation advised against this.  I think I 
> can see why.
> 
> Is there a best practice way of accomplishing this?  Is there any plan 
> to add such functionality in the future?
> 
> -- 
> There are ways and there are ways,
> 
> Geoffry Roberts