MapReduce only uses mapper to write data to multiple hbase tables

Using only mapper without reduce can significantly reduce the time it takes for a mapreduce program to run.

Sometimes the program writes data to multiple hbase tables.

So there is a need for title.

The code given below, not the code that can be run, just shows the necessary items to be set in the driver, the interfaces that the Mapper class needs to implement, the parameters that the map function needs, and how the functions are handled internally.

The implementation of the process is more tortuous, only paste code:

classQos2hbasedriverextendsConfiguredImplementstool{Private StaticLogger Logger =loggerfactory. GetLogger (qos2hbasedriver.class); Private Static Final intDefault_num_reduce = 0; /*** Args[0] Input HDFs file path, args[1] Output table*/@Override Public intRun (string[] args)throwsException {Configuration conf=hbaseconfiguration.create (); Conf.set ("Output", args[1]);//output Table 1Conf.set ("Output2", args[2]);//Output Table 2Job Job=job.getinstance (conf); Job.setjobname ("Iplane_qos2hbase"); Job.setmapperclass (qos2hbasemapper.class); Fileinputformat.setinputpaths (Job, args[0]); Job.setmapoutputkeyclass (immutablebyteswritable.class); Job.setmapoutputvalueclass (Put.class); Job.setoutputformatclass (Multitableoutputformat.class);        Tablemapreduceutil.adddependencyjars (Job);        Tablemapreduceutil.adddependencyjars (Job.getconfiguration ()); Job.setjarbyclass (qos2hbase.class); //set the number of reduce to be adjusted        intNumberreducetasks = 0;        Job.setnumreducetasks (Numberreducetasks); Booleanb = Job.waitforcompletion (true); if(!b) {Logger.error ("Job Error!" "); return-1; }        return0; }}/*** @ClassName: Qos2hbasemapper * @Description: Bring the results into the Mapper class of the HBase library *@authorDangzhang * @date 2014-9-16 pm 1:18:49 **/classQos2hbasemapperextendsMapper<longwritable, Text, immutablebyteswritable, put>{    Private StaticLogger Logger =loggerfactory. GetLogger (qos2hbasemapper.class); @Override Public voidmap (longwritable key, Text line, context context)throwsIOException, interruptedexception {String output= Context.getconfiguration (). Get ("Output"); String Output2= Context.getconfiguration (). Get ("Output2"); //Assembly ROWKEY:IP_IPStringBuffer ROWKEYSB = "AAAA"; Put put=NULL; String Family= "D"; String Qualifier= ""; //direct results into HBase        LongTS =System.currenttimemillis (); Put=NewPut (Bytes.tobytes (rowkeysb.tostring ())); Qualifier= "Del"; Put.add (Bytes.tobytes (family), bytes.tobytes (qualifier), TS, bytes.tobytes (values[6]));//assemble a piece of data            if(!Put.isempty ()) {immutablebyteswritable IB=Newimmutablebyteswritable ();                Ib.set (bytes.tobytes (output)); Context.write (IB, put);//save results to HBase table            }                          //Save History Tablerowkeysb.append (Rowkeyseparator). Append (mydate); Put=NewPut (Bytes.tobytes (rowkeysb.tostring ())); Qualifier= "Del"; Put.add (Bytes.tobytes (family), bytes.tobytes (qualifier), TS, bytes.tobytes (values[6]));//assemble a piece of data            if(!Put.isempty ()) {immutablebyteswritable IB=Newimmutablebyteswritable ();                Ib.set (Bytes.tobytes (OUTPUT2)); Context.write (IB, put);//save results to HBase table            }          }}

MapReduce only uses mapper to write data to multiple hbase tables