Home | About | Sematext search-lucene.com search-hadoop.com
 Search Hadoop and all its subprojects:

Switch to Threaded View
HBase >> mail # user >> Can a RegionObserver coprocessor increment counter of a row key that may not belong to the region ?


Copy link to this message
-
Re: Can a RegionObserver coprocessor increment counter of a row key that may not belong to the region ?
Got it, so if my coprocessor is aggregating through the Increment that was
executed and I am using the aggregated values to increment a new counter in
the *same row and same FAMILIES *but a different qualifier, I should be OK
as long as I use *
 ObserverContext<RegionCoprocessorEnvironment>.getEnvironment().getRegion().incrementColumnValue()
*
?
*
*
On Thu, Dec 6, 2012 at 11:13 AM, Andrew Purtell <[EMAIL PROTECTED]> wrote:

> If you as a coprocessor are not writing back to your own region, you are
> probably doing it wrong.
>
> On Thursday, December 6, 2012, Amit Sela wrote:
>
> > If I'm aggregating over the same Increment Object that triggered the
> > Observer (the same key, same CFs but aggregating into different
> > qualifiers), do I go outside the Region ?
> > I know that for the cases I mentioned earlier I do but in the case I
> > describe here don't I stay in the region ?
> >
> >
> > On Thu, Dec 6, 2012 at 9:40 AM, Andrew Purtell <[EMAIL PROTECTED]
> <javascript:;>>
> > wrote:
> >
> > > Summing/aggregating with a Coprocessor seems like a fine use, but it
> > > should act upon only the data within the region to which it is
> > > associated.
> > >
> > > However if it seems your Coprocessor must unavoidably update or access
> > > data outside of its region, then either your schema design should
> > > change (such that all data the coprocessor will operate on is
> > > contained within the keyspace of the region); or, you should exclude
> > > all possible client side options. For example maybe Datacube will work
> > > for you here? See http://github.com/urbanairship/datacube
> > >
> > > On 12/6/12, Amit Sela <[EMAIL PROTECTED] <javascript:;>> wrote:
> > > > I asked because I thought exactly what you all said but wanted to be
> > > sure.
> > > > My case is incrementing counters per URL where the families are time
> > > > periods (hourly, daily...) and the qualifiers are
> > > > impressions_criteria1,impressions_criteria2... I am going to use
> > > > coprocessors in order to sum all impressions counters (all criteria
> > > > segments) and then increment another counter (general count) that
> > belongs
> > > > to the same URL.
> > > > Is that a good practice for Coprocessors (Observer) ?
> > > >
> > > > Thanks.
> > > >
> > > >
> > > > On Wed, Dec 5, 2012 at 8:56 PM, Asaf Mesika <[EMAIL PROTECTED]
> <javascript:;>
> > >
> > > wrote:
> > > >
> > > >> Why not simply send Increment objects from the client side to HBase,
> > to
> > > >> the URL row key and to the domain row key?
> > > >>
> > > >> On 5 בדצמ 2012, at 14:35, Amit Sela <[EMAIL PROTECTED]
> <javascript:;>>
> > wrote:
> > > >>
> > > >> > Hi all,
> > > >> >
> > > >> > I have to count the occurrence of URLs in our system using the URL
> > as
> > > >> > row
> > > >> > key and using Increment.
> > > >> > I also want to count domains, so I was thinking of using
> > > RegionObserver
> > > >> > coprocessor on postIncrement() and Increment using the domain as
> > key.
> > > >> >
> > > >> > Will that work ? Is there a problem if the url key starts with
> > 'www.'
> > > >> > and
> > > >> > the domain starts with 'aaaa' ?
> > > >> >
> > > >> > Thanks,
> > > >> >
> > > >> > Amit.
> > > >>
> > > >>
> > > >
> > >
> >
>
>
> --
> Best regards,
>
>    - Andy
>
> Problems worthy of attack prove their worth by hitting back. - Piet Hein
> (via Tom White)
>