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.regionserver.wal; 20 21 import java.io.IOException; 22 23 import org.apache.hadoop.fs.Path; 24 import org.apache.hadoop.hbase.HRegionInfo; 25 import org.apache.hadoop.hbase.HTableDescriptor; 26 import org.apache.hadoop.hbase.classification.InterfaceAudience; 27 import org.apache.hadoop.hbase.wal.WALKey; 28 29 /** 30 * Get notification of WAL events. The invocations are inline 31 * so make sure your implementation is fast else you'll slow hbase. 32 */ 33 @InterfaceAudience.Private 34 public interface WALActionsListener { 35 36 /** 37 * The WAL is going to be rolled. The oldPath can be null if this is 38 * the first log file from the regionserver. 39 * @param oldPath the path to the old wal 40 * @param newPath the path to the new wal 41 */ 42 void preLogRoll(Path oldPath, Path newPath) throws IOException; 43 44 /** 45 * The WAL has been rolled. The oldPath can be null if this is 46 * the first log file from the regionserver. 47 * @param oldPath the path to the old wal 48 * @param newPath the path to the new wal 49 */ 50 void postLogRoll(Path oldPath, Path newPath) throws IOException; 51 52 /** 53 * The WAL is going to be archived. 54 * @param oldPath the path to the old wal 55 * @param newPath the path to the new wal 56 */ 57 void preLogArchive(Path oldPath, Path newPath) throws IOException; 58 59 /** 60 * The WAL has been archived. 61 * @param oldPath the path to the old wal 62 * @param newPath the path to the new wal 63 */ 64 void postLogArchive(Path oldPath, Path newPath) throws IOException; 65 66 /** 67 * A request was made that the WAL be rolled. 68 */ 69 void logRollRequested(boolean tooFewReplicas); 70 71 /** 72 * The WAL is about to close. 73 */ 74 void logCloseRequested(); 75 76 /** 77 * Called before each write. 78 * @param info 79 * @param logKey 80 * @param logEdit 81 */ 82 void visitLogEntryBeforeWrite( 83 HRegionInfo info, WALKey logKey, WALEdit logEdit 84 ); 85 86 /** 87 * 88 * @param htd 89 * @param logKey 90 * @param logEdit 91 * TODO: Retire this in favor of {@link #visitLogEntryBeforeWrite(HRegionInfo, WALKey, WALEdit)} 92 * It only exists to get scope when replicating. Scope should be in the WALKey and not need 93 * us passing in a <code>htd</code>. 94 */ 95 void visitLogEntryBeforeWrite(HTableDescriptor htd, WALKey logKey, 96 WALEdit logEdit) throws IOException; 97 98 /** 99 * For notification post append to the writer. Used by metrics system at least. 100 * TODO: Combine this with above. 101 * @param entryLen approx length of cells in this append. 102 * @param elapsedTimeMillis elapsed time in milliseconds. 103 */ 104 void postAppend(final long entryLen, final long elapsedTimeMillis); 105 106 /** 107 * For notification post writer sync. Used by metrics system at least. 108 * @param timeInNanos How long the filesystem sync took in nanoseconds. 109 * @param handlerSyncs How many sync handler calls were released by this call to filesystem 110 * sync. 111 */ 112 void postSync(final long timeInNanos, final int handlerSyncs); 113 114 static class Base implements WALActionsListener { 115 @Override 116 public void preLogRoll(Path oldPath, Path newPath) throws IOException {} 117 118 @Override 119 public void postLogRoll(Path oldPath, Path newPath) throws IOException {} 120 121 @Override 122 public void preLogArchive(Path oldPath, Path newPath) throws IOException {} 123 124 @Override 125 public void postLogArchive(Path oldPath, Path newPath) throws IOException {} 126 127 @Override 128 public void logRollRequested(boolean tooFewReplicas) {} 129 130 @Override 131 public void logCloseRequested() {} 132 133 @Override 134 public void visitLogEntryBeforeWrite(HRegionInfo info, WALKey logKey, WALEdit logEdit) {} 135 136 @Override 137 public void visitLogEntryBeforeWrite(HTableDescriptor htd, WALKey logKey, 138 WALEdit logEdit) throws IOException { 139 } 140 141 @Override 142 public void postAppend(final long entryLen, final long elapsedTimeMillis) {} 143 144 @Override 145 public void postSync(final long timeInNanos, final int handlerSyncs) {} 146 } 147 }