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 <[email protected]>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 <[email protected]>: > > > 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 < > > [email protected]> 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:[email protected]] > > > Sent: Friday, April 11, 2014 10:42 PM > > > To: [email protected] > > > 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 < > > > [email protected]<mailto:[email protected]>> 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:[email protected]] > > > > > > > Sent: Friday, April 11, 2014 12:10 PM > > > > > > > To: [email protected]<mailto:[email protected]> > > > > > > > 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 > > > > > > > <[email protected]<mailto:[email protected]>> > > > > > > > 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
