1 /** 2 * 3 * Licensed to the Apache Software Foundation (ASF) under one 4 * or more contributor license agreements. See the NOTICE file 5 * distributed with this work for additional information 6 * regarding copyright ownership. The ASF licenses this file 7 * to you under the Apache License, Version 2.0 (the 8 * "License"); you may not use this file except in compliance 9 * with the License. You may obtain a copy of the License at 10 * 11 * http://www.apache.org/licenses/LICENSE-2.0 12 * 13 * Unless required by applicable law or agreed to in writing, software 14 * distributed under the License is distributed on an "AS IS" BASIS, 15 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 16 * See the License for the specific language governing permissions and 17 * limitations under the License. 18 */ 19 package org.apache.hadoop.hbase.coprocessor; 20 21 import java.io.IOException; 22 import java.util.List; 23 24 import org.apache.hadoop.hbase.Coprocessor; 25 import org.apache.hadoop.hbase.MetaMutationAnnotation; 26 import org.apache.hadoop.hbase.client.Mutation; 27 import org.apache.hadoop.hbase.regionserver.HRegion; 28 29 public interface RegionServerObserver extends Coprocessor { 30 31 /** 32 * Called before stopping region server. 33 * @param env An instance of RegionServerCoprocessorEnvironment 34 * @throws IOException Signals that an I/O exception has occurred. 35 */ 36 void preStopRegionServer( 37 final ObserverContext<RegionServerCoprocessorEnvironment> env) 38 throws IOException; 39 40 /** 41 * Called before the regions merge. 42 * Call {@link org.apache.hadoop.hbase.coprocessor.ObserverContext#bypass()} to skip the merge. 43 * @throws IOException if an error occurred on the coprocessor 44 * @param ctx 45 * @param regionA 46 * @param regionB 47 * @throws IOException 48 */ 49 void preMerge(final ObserverContext<RegionServerCoprocessorEnvironment> ctx, 50 final HRegion regionA, final HRegion regionB) throws IOException; 51 52 /** 53 * called after the regions merge. 54 * @param c 55 * @param regionA 56 * @param regionB 57 * @param mergedRegion 58 * @throws IOException 59 */ 60 void postMerge(final ObserverContext<RegionServerCoprocessorEnvironment> c, 61 final HRegion regionA, final HRegion regionB, final HRegion mergedRegion) throws IOException; 62 63 /** 64 * This will be called before PONR step as part of regions merge transaction. Calling 65 * {@link org.apache.hadoop.hbase.coprocessor.ObserverContext#bypass()} rollback the merge 66 * @param ctx 67 * @param regionA 68 * @param regionB 69 * @param metaEntries mutations to execute on hbase:meta atomically with regions merge updates. 70 * Any puts or deletes to execute on hbase:meta can be added to the mutations. 71 * @throws IOException 72 */ 73 void preMergeCommit(final ObserverContext<RegionServerCoprocessorEnvironment> ctx, 74 final HRegion regionA, final HRegion regionB, 75 @MetaMutationAnnotation List<Mutation> metaEntries) throws IOException; 76 77 /** 78 * This will be called after PONR step as part of regions merge transaction. 79 * @param ctx 80 * @param regionA 81 * @param regionB 82 * @param mergedRegion 83 * @throws IOException 84 */ 85 void postMergeCommit(final ObserverContext<RegionServerCoprocessorEnvironment> ctx, 86 final HRegion regionA, final HRegion regionB, final HRegion mergedRegion) throws IOException; 87 88 /** 89 * This will be called before the roll back of the regions merge. 90 * @param ctx 91 * @param regionA 92 * @param regionB 93 * @throws IOException 94 */ 95 void preRollBackMerge(final ObserverContext<RegionServerCoprocessorEnvironment> ctx, 96 final HRegion regionA, final HRegion regionB) throws IOException; 97 98 /** 99 * This will be called after the roll back of the regions merge. 100 * @param ctx 101 * @param regionA 102 * @param regionB 103 * @throws IOException 104 */ 105 void postRollBackMerge(final ObserverContext<RegionServerCoprocessorEnvironment> ctx, 106 final HRegion regionA, final HRegion regionB) throws IOException; 107 108 }