/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.hadoop.hbase.coprocessor;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.SortedSet;
import java.util.TreeSet;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
import org.apache.hadoop.hbase.Coprocessor;
import org.apache.hadoop.hbase.CoprocessorEnvironment;
import org.apache.hadoop.hbase.HRegionInfo;
import org.apache.hadoop.hbase.client.Mutation;
import org.apache.hadoop.hbase.regionserver.HRegion;
import org.apache.hadoop.hbase.regionserver.WrongRegionException;
import org.apache.hadoop.hbase.util.Bytes;
import org.apache.hadoop.hbase.protobuf.ProtobufUtil;
import org.apache.hadoop.hbase.protobuf.ResponseConverter;
import org.apache.hadoop.hbase.protobuf.generated.ClientProtos.MutationProto;
import org.apache.hadoop.hbase.protobuf.generated.MultiRowMutation.MultiMutateRequest;
import org.apache.hadoop.hbase.protobuf.generated.MultiRowMutation.MultiMutateResponse;
import org.apache.hadoop.hbase.protobuf.generated.MultiRowMutation.MultiRowMutationService;
import com.google.protobuf.RpcCallback;
import com.google.protobuf.RpcController;
import com.google.protobuf.Service;
/**
* This class demonstrates how to implement atomic multi row transactions using
* {@link HRegion#mutateRowsWithLocks(java.util.Collection, java.util.Collection)}
* and Coprocessor endpoints.
*
* Defines a protocol to perform multi row transactions.
* See {@link MultiRowMutationEndpoint} for the implementation.
* </br>
* See
* {@link HRegion#mutateRowsWithLocks(java.util.Collection, java.util.Collection)}
* for details and limitations.
* </br>
* Example:
* <code><pre>
* List<Mutation> mutations = ...;
* Put p1 = new Put(row1);
* Put p2 = new Put(row2);
* ...
* Mutate m1 = ProtobufUtil.toMutate(MutateType.PUT, p1);
* Mutate m2 = ProtobufUtil.toMutate(MutateType.PUT, p2);
* MultiMutateRequest.Builder mrmBuilder = MultiMutateRequest.newBuilder();
* mrmBuilder.addMutationRequest(m1);
* mrmBuilder.addMutationRequest(m2);
* CoprocessorRpcChannel channel = t.coprocessorService(ROW);
* MultiRowMutationService.BlockingInterface service =
* MultiRowMutationService.newBlockingStub(channel);
* MultiMutateRequest mrm = mrmBuilder.build();
* service.mutateRows(null, mrm);
* </pre></code>
*/
@InterfaceAudience.Public
@InterfaceStability.Evolving
public class MultiRowMutationEndpoint extends MultiRowMutationService implements
CoprocessorService, Coprocessor {
private RegionCoprocessorEnvironment env;
@Override
public void mutateRows(RpcController controller, MultiMutateRequest request,
RpcCallback<MultiMutateResponse> done) {
MultiMutateResponse response = MultiMutateResponse.getDefaultInstance();
try {
// set of rows to lock, sorted to avoid deadlocks
SortedSet<byte[]> rowsToLock = new TreeSet<byte[]>(Bytes.BYTES_COMPARATOR);
List<MutationProto> mutateRequestList = request.getMutationRequestList();
List<Mutation> mutations = new ArrayList<Mutation>(mutateRequestList.size());
for (MutationProto m : mutateRequestList) {
mutations.add(ProtobufUtil.toMutation(m));
}
HRegionInfo regionInfo = env.getRegion().getRegionInfo();
for (Mutation m : mutations) {
// check whether rows are in range for this region
if (!HRegion.rowIsInRange(regionInfo, m.getRow())) {
String msg = "Requested row out of range '"
+ Bytes.toStringBinary(m.getRow()) + "'";
if (rowsToLock.isEmpty()) {
// if this is the first row, region might have moved,
// allow client to retry
throw new WrongRegionException(msg);
} else {
// rows are split between regions, do not retry
throw new org.apache.hadoop.hbase.DoNotRetryIOException(msg);
}
}
rowsToLock.add(m.getRow());
}
// call utility method on region
env.getRegion().mutateRowsWithLocks(mutations, rowsToLock);
} catch (IOException e) {
ResponseConverter.setControllerException(controller, e);
}
done.run(response);
}
@Override
public Service getService() {
return this;
}
/**
* Stores a reference to the coprocessor environment provided by the
* {@link org.apache.hadoop.hbase.regionserver.RegionCoprocessorHost} from the region where this
* coprocessor is loaded. Since this is a coprocessor endpoint, it always expects to be loaded
* on a table region, so always expects this to be an instance of
* {@link RegionCoprocessorEnvironment}.
* @param env the environment provided by the coprocessor host
* @throws IOException if the provided environment is not an instance of
* {@code RegionCoprocessorEnvironment}
*/
@Override
public void start(CoprocessorEnvironment env) throws IOException {
if (env instanceof RegionCoprocessorEnvironment) {
this.env = (RegionCoprocessorEnvironment)env;
} else {
throw new CoprocessorException("Must be loaded on a table region!");
}
}
@Override
public void stop(CoprocessorEnvironment env) throws IOException {
// nothing to do
}
}