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Posted to user@hbase.apache.org by "Bogala, Chandra Reddy" <Ch...@gs.com> on 2014/04/10 13:29:16 UTC

endpoint coprocessor

Hi,
I am planning to write endpoint coprocessor to calculate TOP N results for my usecase.  I got confused with old apis and new apis.
I followed below links and try to implement. But looks like api's changed a lot. I don't see many of these classes in hbase jars. We are using Hbase 0.96.
Can anyone point to the latest document/apis?. And if possible sample code to calculate top N.

https://blogs.apache.org/hbase/entry/coprocessor_introduction
https://www.youtube.com/watch?v=xHvJhuGGOKc

Thanks,
Chandra



RE: endpoint coprocessor

Posted by "Bogala, Chandra Reddy" <Ch...@gs.com>.

Thanks  Yu. I have added below coprocessor to my table. And tried to invoke coprocessor using java client. But fails with below error. But I could see coprocessor in describe table output.



Caused by: org.apache.hadoop.hbase.ipc.RemoteWithExtrasException(org.apache.hadoop.hbase.exceptions.UnknownProtocolException): org.apache.hadoop.hbase.exceptions.UnknownProtocolException: No registered coprocessor service found for name AggregateService in region test3,,1397469869214.c73698dce0d5b91d29d42a9f9e194965.

                at org.apache.hadoop.hbase.regionserver.HRegion.execService(HRegion.java:5070)



>From describe table:

----------------------------------

test3', {TABLE_ATTRIBUTES => {coprocessor$1 => 'hdfs://xxxxxxx.com:8020/user/yyyy/zzzz/hbase-server-0.98.1-hadoop2.jar|org.apache.hadoop.hbase.coprocessor.AggregateImplementation||'}, {NAME => 'cf'



Thanks,

Chandra





-----Original Message-----
From: Ted Yu [mailto:yuzhihong@gmail.com]
Sent: Thursday, April 10, 2014 5:36 PM
To: user@hbase.apache.org
Cc: user@hbase.apache.org
Subject: Re: endpoint coprocessor



Here is a reference implementation for aggregation :

http://search-hadoop.com/c/HBase:hbase-server/src/main/java/org/apache/hadoop/hbase/coprocessor/AggregateImplementation.java||Hbase+aggregation+endpoint



You can find it in hbase source code.

Cheers



On Apr 10, 2014, at 4:29 AM, "Bogala, Chandra Reddy" <Ch...@gs.com>> wrote:



> Hi,

> I am planning to write endpoint coprocessor to calculate TOP N results for my usecase.  I got confused with old apis and new apis.

> I followed below links and try to implement. But looks like api's changed a lot. I don't see many of these classes in hbase jars. We are using Hbase 0.96.

> Can anyone point to the latest document/apis?. And if possible sample code to calculate top N.

>

> https://blogs.apache.org/hbase/entry/coprocessor_introduction

> https://www.youtube.com/watch?v=xHvJhuGGOKc

>

> Thanks,

> Chandra

>

>

Re: endpoint coprocessor

Posted by Ted Yu <yu...@gmail.com>.
Here is a reference implementation for aggregation :
http://search-hadoop.com/c/HBase:hbase-server/src/main/java/org/apache/hadoop/hbase/coprocessor/AggregateImplementation.java||Hbase+aggregation+endpoint

You can find it in hbase source code. 
Cheers

On Apr 10, 2014, at 4:29 AM, "Bogala, Chandra Reddy" <Ch...@gs.com> wrote:

> Hi,
> I am planning to write endpoint coprocessor to calculate TOP N results for my usecase.  I got confused with old apis and new apis.
> I followed below links and try to implement. But looks like api's changed a lot. I don't see many of these classes in hbase jars. We are using Hbase 0.96.
> Can anyone point to the latest document/apis?. And if possible sample code to calculate top N.
> 
> https://blogs.apache.org/hbase/entry/coprocessor_introduction
> https://www.youtube.com/watch?v=xHvJhuGGOKc
> 
> Thanks,
> Chandra
> 
> 

Re: endpoint coprocessor

Posted by anil gupta <an...@gmail.com>.
Hi Bogala,

I am assuming that you are using 0.94. Sorting Coprocessor (
https://issues.apache.org/jira/browse/HBASE-7474) is specifically built for
that. Working patch is available. However, the patch is not commited to
HBase yet so you will need to apply the patch yourself if you need it
quickly. Recently, i added some more features in that CP but i havent
updated the ticket with latest patch. If you are interested, then i will
update the patch. Anyways, i need to revive that Jira and wrap it up.

Thanks,
Anil Gupta


On Sun, Apr 13, 2014 at 8:48 PM, Rabbit's Foot
<ra...@is-land.com.tw>wrote:

> You can think of Endpoint Coprocessor as stored procedures in SQL DBs.
> In order to use an Endpoint Coprocessor you need to build and install it on
> the server side and then it invoke through HBase RPC.
>
> You can make use of
> https://blogs.apache.org/hbase/entry/coprocessor_introduction.
>
>
> 2014-04-14 5:56 GMT+08:00 Ted Yu <yu...@gmail.com>:
>
> > For 0.96+, you can refer
> > to
> >
> hbase-client/src/main/java/org/apache/hadoop/hbase/client/coprocessor/AggregationClient.java
> > as the java client example.
> >
> > Cheers
> >
> >
> >
> > On Fri, Apr 11, 2014 at 6:20 PM, Bogala, Chandra Reddy <
> > Chandra.Bogala@gs.com> wrote:
> >
> > > Thanks Yu. My understanding is, this coprocessor is available as part
> of
> > > Hbase server components. So I should be able to attach this coprocessor
> > to
> > > any of my tables by using alter table command.
> > >
> > >
> > >
> > > alter 'demo-table','COPROCESSOR' =>'<XXXX.jar>|class|priority|args'
> > >
> > >
> > >
> > > Then from hbase shell, I should be able to call this coprocessor with
> > > command. Same like how we do scan and filter. Is there any command like
> > > below(filter command) calling a coprocessor. So that it will run in
> > region
> > > server and return back results?.
> > >
> > >
> > >
> > > scan 'demo-table', {FILTER =>
> > >
> >
> org.apache.hadoop.hbase.filter.RowFilter.new(CompareFilter::CompareOp.valueOf('EQUAL'),SubstringComparator.new("10001|1395309600"))}
> > >
> > >
> > >
> > > I am trying to figure out a simple call mechanism(client) of
> coprocessor.
> > > If by default those classes and calling mechanism not available from
> > hbase
> > > shell. Then planning to use java client code to invoke coprocessor.
> > >
> > > Any pointers to java client to invoke aggregation<
> > >
> >
> http://search-hadoop.com/c/HBase:hbase-server/src/main/java/org/apache/hadoop/hbase/coprocessor/AggregateImplementation.java||Hbase+aggregation+endpoint
> > >
> > > coprocessor will be helpful.
> > >
> > >
> > >
> > > Thanks,
> > >
> > > Chandra
> > >
> > >
> > >
> > > -----Original Message-----
> > > From: Ted Yu [mailto:yuzhihong@gmail.com]
> > > Sent: Friday, April 11, 2014 10:42 PM
> > > To: user@hbase.apache.org
> > > Subject: Re: endpoint coprocessor
> > >
> > >
> > >
> > > Please take a look at :
> > >
> > > hbase-shell/src/main/ruby/hbase/security.rb
> > >
> > >
> > >
> > > for example on how coprocessor is activated from shell.
> > >
> > >
> > >
> > > Cheers
> > >
> > >
> > >
> > >
> > >
> > > On Fri, Apr 11, 2014 at 11:06 AM, Bogala, Chandra Reddy <
> > > Chandra.Bogala@gs.com<ma...@gs.com>> wrote:
> > >
> > >
> > >
> > > > Thank you. I am aware of this challenge. How to call below
> coprocessor
> > >
> > > > from client. Can I call this coprocessor from hbase shell?.  I am new
> > >
> > > > to Hbase. So may be asking very dumb questions.
> > >
> > > >
> > >
> > > > Thanks,
> > >
> > > > Chandra
> > >
> > > >
> > >
> > > > -----Original Message-----
> > >
> > > > From: Asaf Mesika [mailto:asaf.mesika@gmail.com]
> > >
> > > > Sent: Friday, April 11, 2014 12:10 PM
> > >
> > > > To: user@hbase.apache.org<ma...@hbase.apache.org>
> > >
> > > > Subject: Re: endpoint coprocessor
> > >
> > > >
> > >
> > > > Bear in mind each region will return its top n, then you will have to
> > >
> > > > run another top n in your client code. This introduce a numerical
> > >
> > > > error : top on top.
> > >
> > > >
> > >
> > > > On Thursday, April 10, 2014, Bogala, Chandra Reddy
> > >
> > > > <Ch...@gs.com>>
> > >
> > > > wrote:
> > >
> > > >
> > >
> > > > > Hi,
> > >
> > > > > I am planning to write endpoint coprocessor to calculate TOP N
> > >
> > > > > results for my usecase.  I got confused with old apis and new apis.
> > >
> > > > > I followed below links and try to implement. But looks like api's
> > >
> > > > > changed a lot. I don't see many of these classes in hbase jars. We
> > >
> > > > > are using Hbase 0.96.
> > >
> > > > > Can anyone point to the latest document/apis?. And if possible
> > >
> > > > > sample code to calculate top N.
> > >
> > > > >
> > >
> > > > > https://blogs.apache.org/hbase/entry/coprocessor_introduction
> > >
> > > > > HBase Coprocessors - Deploy shared functionality directly on the
> > >
> > > > > cluster<https://www.youtube.com/watch?v=xHvJhuGGOKc>
> > >
> > > > >
> > >
> > > > > Thanks,
> > >
> > > > > Chandra
> > >
> > > > >
> > >
> > > > >
> > >
> > > > >
> > >
> > > >
> > >
> >
>



-- 
Thanks & Regards,
Anil Gupta

Re: endpoint coprocessor

Posted by Rabbit's Foot <ra...@is-land.com.tw>.
You can think of Endpoint Coprocessor as stored procedures in SQL DBs.
In order to use an Endpoint Coprocessor you need to build and install it on
the server side and then it invoke through HBase RPC.

You can make use of
https://blogs.apache.org/hbase/entry/coprocessor_introduction.


2014-04-14 5:56 GMT+08:00 Ted Yu <yu...@gmail.com>:

> For 0.96+, you can refer
> to
> hbase-client/src/main/java/org/apache/hadoop/hbase/client/coprocessor/AggregationClient.java
> as the java client example.
>
> Cheers
>
>
>
> On Fri, Apr 11, 2014 at 6:20 PM, Bogala, Chandra Reddy <
> Chandra.Bogala@gs.com> wrote:
>
> > Thanks Yu. My understanding is, this coprocessor is available as part of
> > Hbase server components. So I should be able to attach this coprocessor
> to
> > any of my tables by using alter table command.
> >
> >
> >
> > alter 'demo-table','COPROCESSOR' =>'<XXXX.jar>|class|priority|args'
> >
> >
> >
> > Then from hbase shell, I should be able to call this coprocessor with
> > command. Same like how we do scan and filter. Is there any command like
> > below(filter command) calling a coprocessor. So that it will run in
> region
> > server and return back results?.
> >
> >
> >
> > scan 'demo-table', {FILTER =>
> >
> org.apache.hadoop.hbase.filter.RowFilter.new(CompareFilter::CompareOp.valueOf('EQUAL'),SubstringComparator.new("10001|1395309600"))}
> >
> >
> >
> > I am trying to figure out a simple call mechanism(client) of coprocessor.
> > If by default those classes and calling mechanism not available from
> hbase
> > shell. Then planning to use java client code to invoke coprocessor.
> >
> > Any pointers to java client to invoke aggregation<
> >
> http://search-hadoop.com/c/HBase:hbase-server/src/main/java/org/apache/hadoop/hbase/coprocessor/AggregateImplementation.java||Hbase+aggregation+endpoint
> >
> > coprocessor will be helpful.
> >
> >
> >
> > Thanks,
> >
> > Chandra
> >
> >
> >
> > -----Original Message-----
> > From: Ted Yu [mailto:yuzhihong@gmail.com]
> > Sent: Friday, April 11, 2014 10:42 PM
> > To: user@hbase.apache.org
> > Subject: Re: endpoint coprocessor
> >
> >
> >
> > Please take a look at :
> >
> > hbase-shell/src/main/ruby/hbase/security.rb
> >
> >
> >
> > for example on how coprocessor is activated from shell.
> >
> >
> >
> > Cheers
> >
> >
> >
> >
> >
> > On Fri, Apr 11, 2014 at 11:06 AM, Bogala, Chandra Reddy <
> > Chandra.Bogala@gs.com<ma...@gs.com>> wrote:
> >
> >
> >
> > > Thank you. I am aware of this challenge. How to call below coprocessor
> >
> > > from client. Can I call this coprocessor from hbase shell?.  I am new
> >
> > > to Hbase. So may be asking very dumb questions.
> >
> > >
> >
> > > Thanks,
> >
> > > Chandra
> >
> > >
> >
> > > -----Original Message-----
> >
> > > From: Asaf Mesika [mailto:asaf.mesika@gmail.com]
> >
> > > Sent: Friday, April 11, 2014 12:10 PM
> >
> > > To: user@hbase.apache.org<ma...@hbase.apache.org>
> >
> > > Subject: Re: endpoint coprocessor
> >
> > >
> >
> > > Bear in mind each region will return its top n, then you will have to
> >
> > > run another top n in your client code. This introduce a numerical
> >
> > > error : top on top.
> >
> > >
> >
> > > On Thursday, April 10, 2014, Bogala, Chandra Reddy
> >
> > > <Ch...@gs.com>>
> >
> > > wrote:
> >
> > >
> >
> > > > Hi,
> >
> > > > I am planning to write endpoint coprocessor to calculate TOP N
> >
> > > > results for my usecase.  I got confused with old apis and new apis.
> >
> > > > I followed below links and try to implement. But looks like api's
> >
> > > > changed a lot. I don't see many of these classes in hbase jars. We
> >
> > > > are using Hbase 0.96.
> >
> > > > Can anyone point to the latest document/apis?. And if possible
> >
> > > > sample code to calculate top N.
> >
> > > >
> >
> > > > https://blogs.apache.org/hbase/entry/coprocessor_introduction
> >
> > > > HBase Coprocessors - Deploy shared functionality directly on the
> >
> > > > cluster<https://www.youtube.com/watch?v=xHvJhuGGOKc>
> >
> > > >
> >
> > > > Thanks,
> >
> > > > Chandra
> >
> > > >
> >
> > > >
> >
> > > >
> >
> > >
> >
>

Re: endpoint coprocessor

Posted by Ted Yu <yu...@gmail.com>.
For 0.96+, you can refer
to hbase-client/src/main/java/org/apache/hadoop/hbase/client/coprocessor/AggregationClient.java
as the java client example.

Cheers



On Fri, Apr 11, 2014 at 6:20 PM, Bogala, Chandra Reddy <
Chandra.Bogala@gs.com> wrote:

> Thanks Yu. My understanding is, this coprocessor is available as part of
> Hbase server components. So I should be able to attach this coprocessor to
> any of my tables by using alter table command.
>
>
>
> alter 'demo-table','COPROCESSOR' =>'<XXXX.jar>|class|priority|args'
>
>
>
> Then from hbase shell, I should be able to call this coprocessor with
> command. Same like how we do scan and filter. Is there any command like
> below(filter command) calling a coprocessor. So that it will run in region
> server and return back results?.
>
>
>
> scan 'demo-table', {FILTER =>
> org.apache.hadoop.hbase.filter.RowFilter.new(CompareFilter::CompareOp.valueOf('EQUAL'),SubstringComparator.new("10001|1395309600"))}
>
>
>
> I am trying to figure out a simple call mechanism(client) of coprocessor.
> If by default those classes and calling mechanism not available from hbase
> shell. Then planning to use java client code to invoke coprocessor.
>
> Any pointers to java client to invoke aggregation<
> http://search-hadoop.com/c/HBase:hbase-server/src/main/java/org/apache/hadoop/hbase/coprocessor/AggregateImplementation.java||Hbase+aggregation+endpoint>
> coprocessor will be helpful.
>
>
>
> Thanks,
>
> Chandra
>
>
>
> -----Original Message-----
> From: Ted Yu [mailto:yuzhihong@gmail.com]
> Sent: Friday, April 11, 2014 10:42 PM
> To: user@hbase.apache.org
> Subject: Re: endpoint coprocessor
>
>
>
> Please take a look at :
>
> hbase-shell/src/main/ruby/hbase/security.rb
>
>
>
> for example on how coprocessor is activated from shell.
>
>
>
> Cheers
>
>
>
>
>
> On Fri, Apr 11, 2014 at 11:06 AM, Bogala, Chandra Reddy <
> Chandra.Bogala@gs.com<ma...@gs.com>> wrote:
>
>
>
> > Thank you. I am aware of this challenge. How to call below coprocessor
>
> > from client. Can I call this coprocessor from hbase shell?.  I am new
>
> > to Hbase. So may be asking very dumb questions.
>
> >
>
> > Thanks,
>
> > Chandra
>
> >
>
> > -----Original Message-----
>
> > From: Asaf Mesika [mailto:asaf.mesika@gmail.com]
>
> > Sent: Friday, April 11, 2014 12:10 PM
>
> > To: user@hbase.apache.org<ma...@hbase.apache.org>
>
> > Subject: Re: endpoint coprocessor
>
> >
>
> > Bear in mind each region will return its top n, then you will have to
>
> > run another top n in your client code. This introduce a numerical
>
> > error : top on top.
>
> >
>
> > On Thursday, April 10, 2014, Bogala, Chandra Reddy
>
> > <Ch...@gs.com>>
>
> > wrote:
>
> >
>
> > > Hi,
>
> > > I am planning to write endpoint coprocessor to calculate TOP N
>
> > > results for my usecase.  I got confused with old apis and new apis.
>
> > > I followed below links and try to implement. But looks like api's
>
> > > changed a lot. I don't see many of these classes in hbase jars. We
>
> > > are using Hbase 0.96.
>
> > > Can anyone point to the latest document/apis?. And if possible
>
> > > sample code to calculate top N.
>
> > >
>
> > > https://blogs.apache.org/hbase/entry/coprocessor_introduction
>
> > > HBase Coprocessors - Deploy shared functionality directly on the
>
> > > cluster<https://www.youtube.com/watch?v=xHvJhuGGOKc>
>
> > >
>
> > > Thanks,
>
> > > Chandra
>
> > >
>
> > >
>
> > >
>
> >
>

RE: endpoint coprocessor

Posted by "Bogala, Chandra Reddy" <Ch...@gs.com>.
Thanks Yu. My understanding is, this coprocessor is available as part of Hbase server components. So I should be able to attach this coprocessor to any of my tables by using alter table command.



alter 'demo-table','COPROCESSOR' =>'<XXXX.jar>|class|priority|args'



Then from hbase shell, I should be able to call this coprocessor with command. Same like how we do scan and filter. Is there any command like below(filter command) calling a coprocessor. So that it will run in region server and return back results?.



scan 'demo-table', {FILTER => org.apache.hadoop.hbase.filter.RowFilter.new(CompareFilter::CompareOp.valueOf('EQUAL'),SubstringComparator.new("10001|1395309600"))}



I am trying to figure out a simple call mechanism(client) of coprocessor. If by default those classes and calling mechanism not available from hbase shell. Then planning to use java client code to invoke coprocessor.

Any pointers to java client to invoke aggregation<http://search-hadoop.com/c/HBase:hbase-server/src/main/java/org/apache/hadoop/hbase/coprocessor/AggregateImplementation.java||Hbase+aggregation+endpoint> coprocessor will be helpful.



Thanks,

Chandra



-----Original Message-----
From: Ted Yu [mailto:yuzhihong@gmail.com]
Sent: Friday, April 11, 2014 10:42 PM
To: user@hbase.apache.org
Subject: Re: endpoint coprocessor



Please take a look at :

hbase-shell/src/main/ruby/hbase/security.rb



for example on how coprocessor is activated from shell.



Cheers





On Fri, Apr 11, 2014 at 11:06 AM, Bogala, Chandra Reddy < Chandra.Bogala@gs.com<ma...@gs.com>> wrote:



> Thank you. I am aware of this challenge. How to call below coprocessor

> from client. Can I call this coprocessor from hbase shell?.  I am new

> to Hbase. So may be asking very dumb questions.

>

> Thanks,

> Chandra

>

> -----Original Message-----

> From: Asaf Mesika [mailto:asaf.mesika@gmail.com]

> Sent: Friday, April 11, 2014 12:10 PM

> To: user@hbase.apache.org<ma...@hbase.apache.org>

> Subject: Re: endpoint coprocessor

>

> Bear in mind each region will return its top n, then you will have to

> run another top n in your client code. This introduce a numerical

> error : top on top.

>

> On Thursday, April 10, 2014, Bogala, Chandra Reddy

> <Ch...@gs.com>>

> wrote:

>

> > Hi,

> > I am planning to write endpoint coprocessor to calculate TOP N

> > results for my usecase.  I got confused with old apis and new apis.

> > I followed below links and try to implement. But looks like api's

> > changed a lot. I don't see many of these classes in hbase jars. We

> > are using Hbase 0.96.

> > Can anyone point to the latest document/apis?. And if possible

> > sample code to calculate top N.

> >

> > https://blogs.apache.org/hbase/entry/coprocessor_introduction

> > HBase Coprocessors - Deploy shared functionality directly on the

> > cluster<https://www.youtube.com/watch?v=xHvJhuGGOKc>

> >

> > Thanks,

> > Chandra

> >

> >

> >

>

Re: endpoint coprocessor

Posted by Ted Yu <yu...@gmail.com>.
Please take a look at :
hbase-shell/src/main/ruby/hbase/security.rb

for example on how coprocessor is activated from shell.

Cheers


On Fri, Apr 11, 2014 at 11:06 AM, Bogala, Chandra Reddy <
Chandra.Bogala@gs.com> wrote:

> Thank you. I am aware of this challenge. How to call below coprocessor
> from client. Can I call this coprocessor from hbase shell?.  I am new to
> Hbase. So may be asking very dumb questions.
>
> Thanks,
> Chandra
>
> -----Original Message-----
> From: Asaf Mesika [mailto:asaf.mesika@gmail.com]
> Sent: Friday, April 11, 2014 12:10 PM
> To: user@hbase.apache.org
> Subject: Re: endpoint coprocessor
>
> Bear in mind each region will return its top n, then you will have to run
> another top n in your client code. This introduce a numerical error : top
> on top.
>
> On Thursday, April 10, 2014, Bogala, Chandra Reddy <Ch...@gs.com>
> wrote:
>
> > Hi,
> > I am planning to write endpoint coprocessor to calculate TOP N results
> > for my usecase.  I got confused with old apis and new apis.
> > I followed below links and try to implement. But looks like api's
> > changed a lot. I don't see many of these classes in hbase jars. We are
> > using Hbase 0.96.
> > Can anyone point to the latest document/apis?. And if possible sample
> > code to calculate top N.
> >
> > https://blogs.apache.org/hbase/entry/coprocessor_introduction
> > HBase Coprocessors - Deploy shared functionality directly on the
> > cluster<https://www.youtube.com/watch?v=xHvJhuGGOKc>
> >
> > Thanks,
> > Chandra
> >
> >
> >
>

RE: endpoint coprocessor

Posted by "Bogala, Chandra Reddy" <Ch...@gs.com>.
Thank you. I am aware of this challenge. How to call below coprocessor from client. Can I call this coprocessor from hbase shell?.  I am new to Hbase. So may be asking very dumb questions.

Thanks,
Chandra

-----Original Message-----
From: Asaf Mesika [mailto:asaf.mesika@gmail.com] 
Sent: Friday, April 11, 2014 12:10 PM
To: user@hbase.apache.org
Subject: Re: endpoint coprocessor

Bear in mind each region will return its top n, then you will have to run another top n in your client code. This introduce a numerical error : top on top.

On Thursday, April 10, 2014, Bogala, Chandra Reddy <Ch...@gs.com>
wrote:

> Hi,
> I am planning to write endpoint coprocessor to calculate TOP N results 
> for my usecase.  I got confused with old apis and new apis.
> I followed below links and try to implement. But looks like api's 
> changed a lot. I don't see many of these classes in hbase jars. We are 
> using Hbase 0.96.
> Can anyone point to the latest document/apis?. And if possible sample 
> code to calculate top N.
>
> https://blogs.apache.org/hbase/entry/coprocessor_introduction
> HBase Coprocessors - Deploy shared functionality directly on the 
> cluster<https://www.youtube.com/watch?v=xHvJhuGGOKc>
>
> Thanks,
> Chandra
>
>
>

Re: endpoint coprocessor

Posted by Asaf Mesika <as...@gmail.com>.
Bear in mind each region will return its top n, then you will have to run
another top n in your client code. This introduce a numerical error : top
on top.

On Thursday, April 10, 2014, Bogala, Chandra Reddy <Ch...@gs.com>
wrote:

> Hi,
> I am planning to write endpoint coprocessor to calculate TOP N results for
> my usecase.  I got confused with old apis and new apis.
> I followed below links and try to implement. But looks like api's changed
> a lot. I don't see many of these classes in hbase jars. We are using Hbase
> 0.96.
> Can anyone point to the latest document/apis?. And if possible sample code
> to calculate top N.
>
> https://blogs.apache.org/hbase/entry/coprocessor_introduction
> HBase Coprocessors - Deploy shared functionality directly on the cluster<https://www.youtube.com/watch?v=xHvJhuGGOKc>
>
> Thanks,
> Chandra
>
>
>