Hi,
I want to implement EndPoint Coprocessor. From the link
(http://www.3pillarglobal.com/insights/hbase-coprocessors) I created my own
files as specified in the link. In the link they worked on Sum but I want to
have Average along with Filters so I did according to what they have specified
in the link and loaded coprocessor in static way. But when I restart the HBase
then in web status of master and regionserver my coprocessor class cannot be
seen.
When I ran client code then I got an error of null pointer exception
My client code is give below
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package coprocessor;
import java.io.IOException;
import java.util.Map;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.client.HConnection;
import org.apache.hadoop.hbase.client.HConnectionManager;
import org.apache.hadoop.hbase.client.HTableInterface;
import org.apache.hadoop.hbase.client.coprocessor.Batch;
import org.apache.hadoop.hbase.ipc.BlockingRpcCallback;
import com.google.protobuf.ServiceException;
import coprocessor.generated.Avg.AvgRequest;
import coprocessor.generated.Avg.AvgResponse;
import coprocessor.generated.Avg.AvgService;
public class TagAggregate {
public static void main(String args[]) throws IOException {
Configuration conf = HBaseConfiguration.create();
HConnection connection =
HConnectionManager.createConnection(conf);
HTableInterface table = connection.getTable("TLG_2");
final AvgRequest request = AvgRequest.newBuilder()
.setFamily("TagsOnDate").setColumn("ValueFloat").build();
try {
Map<byte[], Long> results = table.coprocessorService(
AvgService.class, null, null,
new Batch.Call<AvgService, Long>() {
@Override
public Long call(AvgService
aggregate)
throws
IOException {
BlockingRpcCallback
rpcCallback = new BlockingRpcCallback();
aggregate.getAvg(null,
request, rpcCallback);
System.out.println("rpcCallback.get() value is " +rpcCallback.get());
AvgResponse response
=(AvgResponse) rpcCallback.get();
System.out.println("response.hasAvg():" +response.hasAvg());
return (long)
(response.hasAvg() ? response.getAvg() : 0L);
}
});
for (Long avg : results.values()) {
System.out.println("Avg = " + avg);
}
} catch (ServiceException e) {
e.printStackTrace();
} catch (Throwable e) {
e.printStackTrace();
}
}
}
Error I got after running client code
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
rpcCallback.get() value is null
java.lang.NullPointerException
at coprocessor.TagAggregate$1.call(TagAggregate.java:43)
at coprocessor.TagAggregate$1.call(TagAggregate.java:1)
at org.apache.hadoop.hbase.client.HTable$17.call(HTable.java:1629)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)
