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HBase, mail # user - Co-Processor in scanning the HBase's Table


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Re: Co-Processor in scanning the HBase's Table
Anoop John 2013-02-22, 18:04
yes what Ted mentioned, u can try out..

-Anoop-

On Fri, Feb 22, 2013 at 7:46 PM, Ted <[EMAIL PROTECTED]> wrote:

> Hbase-5416 should help your use case.
> Cf2 would be the essential column family.
>
> This feature is available in 0.94.5
>
> Cheers
>
> On Feb 22, 2013, at 5:55 AM, Farrokh Shahriari <
> [EMAIL PROTECTED]> wrote:
>
> > @Anoop : Here is my situation: I have 2 columnFamilies(cf1,cf2),5-50
> > qualifiers(they are variable),first I should check the value of
> qualifiers
> > in cf2,then if they equal to some values I'm going to get the values of
> cf1
> > by that rowkey.
> >
> > @Amita: thank you.I will check that too.
> >
> > Farrokh
> > On Thu, Feb 21, 2013 at 8:58 PM, Amit Sela <[EMAIL PROTECTED]> wrote:
> >
> >> I think that if your intention is to do some kind of scan filtering on
> the
> >> server side then maybe an EndPoint coprocessor would be more fitting.
> >> You can iterate over the InternalScanner and return a Map<> with your
> >> filtered values.
> >>
> >> You can also check this link:
> >>
> http://hbase-coprocessor-experiments.blogspot.co.il/2011/05/extending.html
> >>
> >> Good Luck!
> >>
> >> On Thu, Feb 21, 2013 at 5:52 PM, Anoop John <[EMAIL PROTECTED]>
> wrote:
> >>
> >>> What is this filtering at client side doing exactly?
> >>> postScannerClose() wont deal with any scanned data.  This hook will be
> >>> called later..  You should be using hooks with scanner's next calls.
> >> Mind
> >>> telling the exact thing you are doing now at client side. Then we might
> >> be
> >>> able to suggest some thing.
> >>>
> >>> -Anoop-
> >>>
> >>> On Thu, Feb 21, 2013 at 7:14 PM, Farrokh Shahriari <
> >>> [EMAIL PROTECTED]> wrote:
> >>>
> >>>> Hello again,
> >>>> I've used PostScannerClose Regionobserver as the hbase book
> (Definitive
> >>>> Guide) says,but it doesn't seem worked.And I noticed that the
> >>>> PostScannerClose doesn't return any value like result.
> >>>> In fact,I just wanna doing a simple job as described below:
> >>>> Up to now,I've used a scanner to filter the columnFamily,then on the
> >>> client
> >>>> side ( means at the result loop), filtered some other things,now I
> want
> >>> to
> >>>> do that after scanning each region to reduce the amount of return
> >> results
> >>>> to client.
> >>>>
> >>>> Please help me,I need it asap.
> >>>>
> >>>> Farrokh
> >>>>
> >>>> On Tue, Feb 19, 2013 at 9:03 PM, Farrokh Shahriari <
> >>>> [EMAIL PROTECTED]> wrote:
> >>>>
> >>>>> Thanks you guys
> >>>>>
> >>>>>
> >>>>> On Mon, Feb 18, 2013 at 12:00 PM, Amit Sela <[EMAIL PROTECTED]>
> >>> wrote:
> >>>>>
> >>>>>> Yes... that was emailing half asleep... :)
> >>>>>>
> >>>>>> On Mon, Feb 18, 2013 at 7:23 AM, Anoop Sam John <[EMAIL PROTECTED]
> >>>
> >>>>>> wrote:
> >>>>>>
> >>>>>>> We dont have any hook like postScan()..  In ur case you can try
> >> with
> >>>>>>> postScannerClose()..  This will be called once per region. When
> >> the
> >>>>>> scan on
> >>>>>>> that region is over the scanner opened on that region will get
> >>> closed
> >>>>>> and
> >>>>>>> at that time this hook will get executed.
> >>>>>>>
> >>>>>>> -Anoop-
> >>>>>>> ________________________________________
> >>>>>>> From: Farrokh Shahriari [[EMAIL PROTECTED]]
> >>>>>>> Sent: Monday, February 18, 2013 10:27 AM
> >>>>>>> To: [EMAIL PROTECTED]
> >>>>>>> Cc: [EMAIL PROTECTED]
> >>>>>>> Subject: Re: Co-Processor in scanning the HBase's Table
> >>>>>>>
> >>>>>>> Thanks you Amit,I will check that.
> >>>>>>> @Anoop: I wanna run that just after scanning a region or after
> >>>> scanning
> >>>>>> the
> >>>>>>> regions that to belong to one regionserver.
> >>>>>>>
> >>>>>>> On Mon, Feb 18, 2013 at 7:45 AM, Anoop Sam John <
> >> [EMAIL PROTECTED]
> >>>>
> >>>>>>> wrote:
> >>>>>>>
> >>>>>>>>> I wanna use a custom code after scanning a large table and
> >> prefer
> >>>> to
> >>>>>> run
> >>>>>>>> the code after scanning each region
> >>>>>>>>
> >>>>>>>> Exactly at what point you want to run your custom code?  We have