The only way to register endpoint coprocessor jars is by placing them in
lib dir if hbase and modifying hbase-site.xml to point to it under a
property name I forgot at the moment.
What you described is a way to register an Observer type coprocessor.
On Friday, July 12, 2013, ch huang wrote:
> i am testing coprocessor endpoint function, here is my testing process ,and
> error i get ,hope any expert on coprocessor can help me out
>
>
> # vi ColumnAggregationProtocol.java
>
> import java.io.IOException;
> import org.apache.hadoop.hbase.ipc.CoprocessorProtocol;
> // A sample protocol for performing aggregation at regions.
> public interface ColumnAggregationProtocol
> extends CoprocessorProtocol {
> // Perform aggregation for a given column at the region. The aggregation
> // will include all the rows inside the region. It can be extended to
> // allow passing start and end rows for a fine-grained aggregation.
> public long sum(byte[] family, byte[] qualifier) throws IOException;
> }
>
>
> # vi ColumnAggregationEndpoint.java
>
>
> import java.io.FileWriter;
> import java.io.IOException;
> import java.util.ArrayList;
> import java.util.List;
> import org.apache.hadoop.hbase.CoprocessorEnvironment;
> import org.apache.hadoop.hbase.KeyValue;
> import org.apache.hadoop.hbase.client.Scan;
> import org.apache.hadoop.hbase.coprocessor.BaseEndpointCoprocessor;
> import org.apache.hadoop.hbase.coprocessor.RegionCoprocessorEnvironment;
> import org.apache.hadoop.hbase.ipc.ProtocolSignature;
> import org.apache.hadoop.hbase.regionserver.HRegion;
> import org.apache.hadoop.hbase.regionserver.InternalScanner;
> import org.apache.hadoop.hbase.util.Bytes;
>
> //Aggregation implementation at a region.
>
> public class ColumnAggregationEndpoint extends BaseEndpointCoprocessor
> implements ColumnAggregationProtocol {
> @Override
> public long sum(byte[] family, byte[] qualifier)
> throws IOException {
> // aggregate at each region
> Scan scan = new Scan();
> scan.addColumn(family, qualifier);
> long sumResult = 0;
>
> CoprocessorEnvironment ce = getEnvironment();
> HRegion hr = ((RegionCoprocessorEnvironment)ce).getRegion();
> InternalScanner scanner = hr.getScanner(scan);
>
> try {
> List<KeyValue> curVals = new ArrayList<KeyValue>();
> boolean hasMore = false;
> do {
> curVals.clear();
> hasMore = scanner.next(curVals);
> KeyValue kv = curVals.get(0);
> sumResult += Long.parseLong(Bytes.toString(kv.getValue()));
>
> } while (hasMore);
> } finally {
> scanner.close();
> }
> return sumResult;
> }
>
> @Override
> public long getProtocolVersion(String protocol, long clientVersion)
> throws IOException {
> // TODO Auto-generated method stub
> return 0;
> }
>
> @Override
>
> public ProtocolSignature getProtocolSignature(String protocol,
> long clientVersion, int clientMethodsHash) throws IOException
> {
> // TODO Auto-generated method stub
> return null;
> }
> }
>
> i compile and pack the two into test.jar,and put it into my HDFS filesystem
>
> and load it into my test table
>
> hbase(main):006:0> alter 'mytest', METHOD =>
> 'table_att','coprocessor'=>'hdfs:///
> 192.168.10.22:9000/alex/test.jar|ColumnAggregationEndpoint|1001'
>
> here is my testing java code
>
> package com.testme.demo;
> 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.HTableDescriptor;
> import org.apache.hadoop.hbase.client.*;
> import org.apache.hadoop.hbase.coprocessor.ColumnAggregationProtocol;
> import org.apache.hadoop.hbase.util.*;
> import org.apache.hadoop.hbase.client.coprocessor.Batch.Call;;
>
> public class TestCop {
> private static Configuration conf =null;
> private static String TEST_TABLE = "mytest";
> private static String TEST_FAMILY = "myfl";
> private static String TEST_QUALIFIER = "myqf";
> /**
> * @param args
> */
> static {
> conf = HBaseConfiguration.create();
> conf.addResource( "hbase-site.xml");
> }
>
> public static void main(String[] args) throws IOException,Throwable{
> // TODO Auto-generated method stub
> conf = HBaseConfiguration.create();
>
> HTable table = new HTable(conf,TEST_TABLE);
> // HTableDescriptor htd = table.getTableDescriptor();
>
> Scan scan = new Scan();
> Map<byte[], Long> results;
>
> results = table.coprocessorExec(ColumnAggregationProtocol.class,
> "1".getBytes(),"5".getBytes(), new Call<ColumnAggregationProtocol,Long>(){
> public Long call(ColumnAggregationProtocol instance)throws
> IOException{
> return (Long) instance.sum(TEST_FAMILY.getBytes(),
> TEST_QUALIFIER.getBytes());
> }});
>
> long sumResult = 0;
> long expectedResult = 0;
> for (Map.Entry<byte[], Long> e:results.entrySet()){
> sumResult += e.getValue();
> }
> System.out.println(sumResult);
> }
> }
> when i run it i get error
> Exception in thread "main"
> org.apache.hadoop.hbase.ipc.HBaseRPC$UnknownProtocolException:
> org.apache.hadoop.hbase.ipc.HBaseRPC$UnknownProtocolException: No matching
> handler for protocol
> org.apache.hadoop.hbase.coprocessor.ColumnAggregationProtocol in region
> mytest,,1373597714844.e11ad2263faf89b5865ae98f524e3fb9.
> at org.apache.hadoop.hbase.regionserver.HRegion.exec(HRegion.java:5463)
> at
>
> org.apache.hadoop.hbase.regionserver.HRegionServer.execCoprocessor(HRegionServer.java:3720)
> at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
> at
>
> sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
> at
>
> sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
> at java.lang.reflect.Method.invoke(Method.java:597)
> at
>
> org.apache.hadoop.hbase.ipc.WritableRpcEngine$Server.call(WritableRpcEngine.java:320)
> at
> org.apache.hadoop.hbase.ipc.HBaseServer$Handler.run(HBaseServer.java:1426)
> at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
> at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
> at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown
> Source)
> at java.lang.reflect.Constructor.newInstance(Unknown Source)
> at
>
> org.apache.hadoop.ipc.RemoteException.instantiateException(RemoteException.java:90)
> at
>
> org.apache.hadoop.ipc.RemoteException.unwrapRemoteException(RemoteException.java:79)
> at
>
> org.apache.hadoop.hbase.client.ServerCallable.translateException(ServerCallable.java:228)
> at
>
> org.apache.hadoop.hbase.client.ServerCallable.withRetries(ServerCallable.java:166)
> at
> org.apache.hadoop.hbase.ipc.ExecRPCInvoker.invoke(ExecRPCInvoker.java:79)
> at com.sun.proxy.$Proxy8.sum(Unknown Source)
> at com.testme.demo.TestCop$1.call(TestCop.java:41)
> at com.testme.demo.TestCop$1.call(TestCop.java:1)
> at
>
> org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementation$4.call(HConnectionManager.java:1466)
> at java.util.concurrent.FutureTask$Sync.innerRun(Unknown Source)
> at java.util.concurrent.FutureTask.run(Unknown Source)
> at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
> at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
> at java.lang.Thread.run(Unknown Source)
> Caused by:
>
> org.apache.hadoop.ipc.RemoteException(org.apache.hadoop.hbase.ipc.HBaseRPC$UnknownProtocolException):
> org.apache.hadoop.hbase.ipc.HBaseRPC$UnknownProtocolException: No matching
> handler for protocol
> org.apache.hadoop.hbase.coprocessor.ColumnAggregationProtocol in region
> mytest,,1373597714844.e11ad2263faf89b5865ae98f524e3fb9.
> at org.apache.hadoop.hbase.regionserver.HRegion.exec(HRegion.java:5463)
> at
>
> org.apache.hadoop.hbase.regionserver.HRegionServer.execCoprocessor(HRegionServer.java:3720)
> at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
> at
>
> sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
> at
>
> sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
> at java.lang.reflect.Method.invoke(Method.java:597)
> at
>
> org.apache.hadoop.hbase.ipc.WritableRpcEngine$Server.call(WritableRpcEngine.java:320)
> at
> org.apache.hadoop.hbase.ipc.HBaseServer$Handler.run(HBaseServer.java:1426)
> at org.apache.hadoop.hbase.ipc.HBaseClient.call(HBaseClient.java:995)
> at
>
> org.apache.hadoop.hbase.ipc.WritableRpcEngine$Invoker.invoke(WritableRpcEngine.java:86)
> at com.sun.proxy.$Proxy7.execCoprocessor(Unknown Source)
> at
> org.apache.hadoop.hbase.ipc.ExecRPCInvoker$1.call(ExecRPCInvoker.java:75)
> at
> org.apache.hadoop.hbase.ipc.ExecRPCInvoker$1.call(ExecRPCInvoker.java:73)
> at
>
> org.apache.hadoop.hbase.client.ServerCallable.withRetries(ServerCallable.java:163)
> ... 10 more
>
> hbase(main):020:0> describe
> 'mytest'
> DESCRIPTION ENABLED
> {NAME => 'mytest', coprocessor$1 => 'hdfs:///192.16 true
> 8.10.22:9000/alex/test.jar|ColumnAggregationEndpoin
> t|1001', FAMILIES => [{NAME => 'myfl'
> , DATA_BLOCK_ENCODING => 'NONE', BLOOMFILTER => 'NO
> NE', REPLICATION_SCOPE => '0', VERSIONS => '3', COM
> PRESSION => 'NONE', MIN_VERSIONS => '0', TTL => '21
> 47483647', KEEP_DELETED_CELLS => 'false', BLOCKSIZE
> => '65536', IN_MEMORY => 'false', ENCODE_ON_DISK =
> > 'true', BLOCKCACHE => 'true'}]}
> 1 row(s) in 0.0920 seconds
>
