You can take a look at the following from Phoenix: phoenix-core/src/main/java/org/apache/phoenix/coprocessor/GroupedAggregateRegionObserver.java
On Wed, May 17, 2017 at 1:59 AM, Rajeshkumar J <[email protected]> wrote: > Hi, > > I want to groupby hbase data by some columns and again I want to group > the resultant data by some columns and check the size of each group if > greater than 1 it will be written to hdfs. Initially we are doing this in > mapreduce but we got some issue in reducer. So we thought we can move this > group by operation to hbase using coprocessor. > Hence using this coprocessor we will scan and group data by some columns > . Then again I want to group the resultant data how to achieve this in > coprocessor?? whether this use case fits in coprocessor?? > > Thanks > > On Wed, May 17, 2017 at 1:28 PM, Ted Yu <[email protected]> wrote: > > > Can you clarify your use case ? > > > > If your mapper calls Table#coprocessorService(), the recipient may not be > > on the same region server as the mapper. > > > > On Tue, May 16, 2017 at 10:58 PM, Rajeshkumar J < > > [email protected] > > > wrote: > > > > > Hi, > > > > > > whether I can call hase coprocessor in the map function of mapreduce > > > job? > > > > > > Thanks > > > > > >
