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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
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
>>>>>> hooks at
>>>>>>>> points like opening a scanner at a region, closing scanner at a
>>>>>> region,
>>>>>>>> calling next (pre/post) etc
>>>>>>>>
>>>>>>>> -Anoop-
>>>>>>>> ________________________________________
>>>>>>>> From: Farrokh Shahriari [[EMAIL PROTECTED]]
>>>>>>>> Sent: Monday, February 18, 2013 12:21 AM