/**
*
* 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.List;
import org.apache.hadoop.hbase.CellScanner;
import org.apache.hadoop.hbase.Coprocessor;
import org.apache.hadoop.hbase.MetaMutationAnnotation;
import org.apache.hadoop.hbase.client.Mutation;
import org.apache.hadoop.hbase.protobuf.generated.AdminProtos.WALEntry;
import org.apache.hadoop.hbase.regionserver.HRegion;
import org.apache.hadoop.hbase.replication.ReplicationEndpoint;
public interface RegionServerObserver extends Coprocessor {
/**
* Called before stopping region server.
* @param env An instance of RegionServerCoprocessorEnvironment
* @throws IOException Signals that an I/O exception has occurred.
*/
void preStopRegionServer(
final ObserverContext<RegionServerCoprocessorEnvironment> env)
throws IOException;
/**
* Called before the regions merge.
* Call {@link org.apache.hadoop.hbase.coprocessor.ObserverContext#bypass()} to skip the merge.
* @throws IOException if an error occurred on the coprocessor
* @param ctx
* @param regionA
* @param regionB
* @throws IOException
*/
void preMerge(final ObserverContext<RegionServerCoprocessorEnvironment> ctx,
final HRegion regionA, final HRegion regionB) throws IOException;
/**
* called after the regions merge.
* @param c
* @param regionA
* @param regionB
* @param mergedRegion
* @throws IOException
*/
void postMerge(final ObserverContext<RegionServerCoprocessorEnvironment> c,
final HRegion regionA, final HRegion regionB, final HRegion mergedRegion) throws IOException;
/**
* This will be called before PONR step as part of regions merge transaction. Calling
* {@link org.apache.hadoop.hbase.coprocessor.ObserverContext#bypass()} rollback the merge
* @param ctx
* @param regionA
* @param regionB
* @param metaEntries mutations to execute on hbase:meta atomically with regions merge updates.
* Any puts or deletes to execute on hbase:meta can be added to the mutations.
* @throws IOException
*/
void preMergeCommit(final ObserverContext<RegionServerCoprocessorEnvironment> ctx,
final HRegion regionA, final HRegion regionB,
@MetaMutationAnnotation List<Mutation> metaEntries) throws IOException;
/**
* This will be called after PONR step as part of regions merge transaction.
* @param ctx
* @param regionA
* @param regionB
* @param mergedRegion
* @throws IOException
*/
void postMergeCommit(final ObserverContext<RegionServerCoprocessorEnvironment> ctx,
final HRegion regionA, final HRegion regionB, final HRegion mergedRegion) throws IOException;
/**
* This will be called before the roll back of the regions merge.
* @param ctx
* @param regionA
* @param regionB
* @throws IOException
*/
void preRollBackMerge(final ObserverContext<RegionServerCoprocessorEnvironment> ctx,
final HRegion regionA, final HRegion regionB) throws IOException;
/**
* This will be called after the roll back of the regions merge.
* @param ctx
* @param regionA
* @param regionB
* @throws IOException
*/
void postRollBackMerge(final ObserverContext<RegionServerCoprocessorEnvironment> ctx,
final HRegion regionA, final HRegion regionB) throws IOException;
/**
* This will be called before executing user request to roll a region server WAL.
* @param ctx An instance of ObserverContext
* @throws IOException Signals that an I/O exception has occurred.
*/
void preRollWALWriterRequest(final ObserverContext<RegionServerCoprocessorEnvironment> ctx)
throws IOException;
/**
* This will be called after executing user request to roll a region server WAL.
* @param ctx An instance of ObserverContext
* @throws IOException Signals that an I/O exception has occurred.
*/
void postRollWALWriterRequest(final ObserverContext<RegionServerCoprocessorEnvironment> ctx)
throws IOException;
/**
* This will be called after the replication endpoint is instantiated.
* @param ctx
* @param endpoint - the base endpoint for replication
* @return the endpoint to use during replication.
*/
ReplicationEndpoint postCreateReplicationEndPoint(
ObserverContext<RegionServerCoprocessorEnvironment> ctx, ReplicationEndpoint endpoint);
/**
* This will be called before executing replication request to shipping log entries.
* @param ctx An instance of ObserverContext
* @param entries list of WALEntries to replicate
* @param cells Cells that the WALEntries refer to (if cells is non-null)
* @throws IOException Signals that an I/O exception has occurred.
*/
void preReplicateLogEntries(final ObserverContext<RegionServerCoprocessorEnvironment> ctx,
List<WALEntry> entries, CellScanner cells) throws IOException;
/**
* This will be called after executing replication request to shipping log entries.
* @param ctx An instance of ObserverContext
* @param entries list of WALEntries to replicate
* @param cells Cells that the WALEntries refer to (if cells is non-null)
* @throws IOException Signals that an I/O exception has occurred.
*/
void postReplicateLogEntries(final ObserverContext<RegionServerCoprocessorEnvironment> ctx,
List<WALEntry> entries, CellScanner cells) throws IOException;
}