1 /** 2 * Licensed to the Apache Software Foundation (ASF) under one 3 * or more contributor license agreements. See the NOTICE file 4 * distributed with this work for additional information 5 * regarding copyright ownership. The ASF licenses this file 6 * to you under the Apache License, Version 2.0 (the 7 * "License"); you may not use this file except in compliance 8 * with the License. You may obtain a copy of the License at 9 * 10 * http://www.apache.org/licenses/LICENSE-2.0 11 * 12 * Unless required by applicable law or agreed to in writing, software 13 * distributed under the License is distributed on an "AS IS" BASIS, 14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 15 * See the License for the specific language governing permissions and 16 * limitations under the License. 17 */ 18 package org.apache.hadoop.hbase.snapshot; 19 20 import java.io.IOException; 21 import java.util.Collections; 22 23 import org.apache.commons.logging.Log; 24 import org.apache.commons.logging.LogFactory; 25 import org.apache.hadoop.conf.Configuration; 26 import org.apache.hadoop.fs.FSDataInputStream; 27 import org.apache.hadoop.fs.FSDataOutputStream; 28 import org.apache.hadoop.fs.FileSystem; 29 import org.apache.hadoop.fs.Path; 30 import org.apache.hadoop.fs.permission.FsPermission; 31 import org.apache.hadoop.hbase.HConstants; 32 import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.SnapshotDescription; 33 import org.apache.hadoop.hbase.snapshot.SnapshotManifestV2; 34 import org.apache.hadoop.hbase.util.EnvironmentEdgeManager; 35 import org.apache.hadoop.hbase.util.FSUtils; 36 37 /** 38 * Utility class to help manage {@link SnapshotDescription SnapshotDesriptions}. 39 * <p> 40 * Snapshots are laid out on disk like this: 41 * 42 * <pre> 43 * /hbase/.snapshots 44 * /.tmp <---- working directory 45 * /[snapshot name] <----- completed snapshot 46 * </pre> 47 * 48 * A completed snapshot named 'completed' then looks like (multiple regions, servers, files, etc. 49 * signified by '...' on the same directory depth). 50 * 51 * <pre> 52 * /hbase/.snapshots/completed 53 * .snapshotinfo <--- Description of the snapshot 54 * .tableinfo <--- Copy of the tableinfo 55 * /.logs 56 * /[server_name] 57 * /... [log files] 58 * ... 59 * /[region name] <---- All the region's information 60 * .regioninfo <---- Copy of the HRegionInfo 61 * /[column family name] 62 * /[hfile name] <--- name of the hfile in the real region 63 * ... 64 * ... 65 * ... 66 * </pre> 67 * 68 * Utility methods in this class are useful for getting the correct locations for different parts of 69 * the snapshot, as well as moving completed snapshots into place (see 70 * {@link #completeSnapshot}, and writing the 71 * {@link SnapshotDescription} to the working snapshot directory. 72 */ 73 public class SnapshotDescriptionUtils { 74 75 /** 76 * Filter that only accepts completed snapshot directories 77 */ 78 public static class CompletedSnaphotDirectoriesFilter extends FSUtils.BlackListDirFilter { 79 80 /** 81 * @param fs 82 */ 83 public CompletedSnaphotDirectoriesFilter(FileSystem fs) { 84 super(fs, Collections.singletonList(SNAPSHOT_TMP_DIR_NAME)); 85 } 86 } 87 88 private static final Log LOG = LogFactory.getLog(SnapshotDescriptionUtils.class); 89 /** 90 * Version of the fs layout for a snapshot. Future snapshots may have different file layouts, 91 * which we may need to read in differently. 92 */ 93 public static final int SNAPSHOT_LAYOUT_VERSION = SnapshotManifestV2.DESCRIPTOR_VERSION; 94 95 // snapshot directory constants 96 /** 97 * The file contains the snapshot basic information and it is under the directory of a snapshot. 98 */ 99 public static final String SNAPSHOTINFO_FILE = ".snapshotinfo"; 100 101 /** Temporary directory under the snapshot directory to store in-progress snapshots */ 102 public static final String SNAPSHOT_TMP_DIR_NAME = ".tmp"; 103 // snapshot operation values 104 /** Default value if no start time is specified */ 105 public static final long NO_SNAPSHOT_START_TIME_SPECIFIED = 0; 106 107 public static final String MASTER_SNAPSHOT_TIMEOUT_MILLIS = "hbase.snapshot.master.timeout.millis"; 108 109 /** By default, wait 60 seconds for a snapshot to complete */ 110 public static final long DEFAULT_MAX_WAIT_TIME = 60000; 111 112 private SnapshotDescriptionUtils() { 113 // private constructor for utility class 114 } 115 116 /** 117 * @param conf {@link Configuration} from which to check for the timeout 118 * @param type type of snapshot being taken 119 * @param defaultMaxWaitTime Default amount of time to wait, if none is in the configuration 120 * @return the max amount of time the master should wait for a snapshot to complete 121 */ 122 public static long getMaxMasterTimeout(Configuration conf, SnapshotDescription.Type type, 123 long defaultMaxWaitTime) { 124 String confKey; 125 switch (type) { 126 case DISABLED: 127 default: 128 confKey = MASTER_SNAPSHOT_TIMEOUT_MILLIS; 129 } 130 return conf.getLong(confKey, defaultMaxWaitTime); 131 } 132 133 /** 134 * Get the snapshot root directory. All the snapshots are kept under this directory, i.e. 135 * ${hbase.rootdir}/.snapshot 136 * @param rootDir hbase root directory 137 * @return the base directory in which all snapshots are kept 138 */ 139 public static Path getSnapshotRootDir(final Path rootDir) { 140 return new Path(rootDir, HConstants.SNAPSHOT_DIR_NAME); 141 } 142 143 /** 144 * Get the directory for a specified snapshot. This directory is a sub-directory of snapshot root 145 * directory and all the data files for a snapshot are kept under this directory. 146 * @param snapshot snapshot being taken 147 * @param rootDir hbase root directory 148 * @return the final directory for the completed snapshot 149 */ 150 public static Path getCompletedSnapshotDir(final SnapshotDescription snapshot, final Path rootDir) { 151 return getCompletedSnapshotDir(snapshot.getName(), rootDir); 152 } 153 154 /** 155 * Get the directory for a completed snapshot. This directory is a sub-directory of snapshot root 156 * directory and all the data files for a snapshot are kept under this directory. 157 * @param snapshotName name of the snapshot being taken 158 * @param rootDir hbase root directory 159 * @return the final directory for the completed snapshot 160 */ 161 public static Path getCompletedSnapshotDir(final String snapshotName, final Path rootDir) { 162 return getCompletedSnapshotDir(getSnapshotsDir(rootDir), snapshotName); 163 } 164 165 /** 166 * Get the general working directory for snapshots - where they are built, where they are 167 * temporarily copied on export, etc. 168 * @param rootDir root directory of the HBase installation 169 * @return Path to the snapshot tmp directory, relative to the passed root directory 170 */ 171 public static Path getWorkingSnapshotDir(final Path rootDir) { 172 return new Path(getSnapshotsDir(rootDir), SNAPSHOT_TMP_DIR_NAME); 173 } 174 175 /** 176 * Get the directory to build a snapshot, before it is finalized 177 * @param snapshot snapshot that will be built 178 * @param rootDir root directory of the hbase installation 179 * @return {@link Path} where one can build a snapshot 180 */ 181 public static Path getWorkingSnapshotDir(SnapshotDescription snapshot, final Path rootDir) { 182 return getCompletedSnapshotDir(getWorkingSnapshotDir(rootDir), snapshot.getName()); 183 } 184 185 /** 186 * Get the directory to build a snapshot, before it is finalized 187 * @param snapshotName name of the snapshot 188 * @param rootDir root directory of the hbase installation 189 * @return {@link Path} where one can build a snapshot 190 */ 191 public static Path getWorkingSnapshotDir(String snapshotName, final Path rootDir) { 192 return getCompletedSnapshotDir(getWorkingSnapshotDir(rootDir), snapshotName); 193 } 194 195 /** 196 * Get the directory to store the snapshot instance 197 * @param snapshotsDir hbase-global directory for storing all snapshots 198 * @param snapshotName name of the snapshot to take 199 * @return the final directory for the completed snapshot 200 */ 201 private static final Path getCompletedSnapshotDir(final Path snapshotsDir, String snapshotName) { 202 return new Path(snapshotsDir, snapshotName); 203 } 204 205 /** 206 * @param rootDir hbase root directory 207 * @return the directory for all completed snapshots; 208 */ 209 public static final Path getSnapshotsDir(Path rootDir) { 210 return new Path(rootDir, HConstants.SNAPSHOT_DIR_NAME); 211 } 212 213 /** 214 * Convert the passed snapshot description into a 'full' snapshot description based on default 215 * parameters, if none have been supplied. This resolves any 'optional' parameters that aren't 216 * supplied to their default values. 217 * @param snapshot general snapshot descriptor 218 * @param conf Configuration to read configured snapshot defaults if snapshot is not complete 219 * @return a valid snapshot description 220 * @throws IllegalArgumentException if the {@link SnapshotDescription} is not a complete 221 * {@link SnapshotDescription}. 222 */ 223 public static SnapshotDescription validate(SnapshotDescription snapshot, Configuration conf) 224 throws IllegalArgumentException { 225 if (!snapshot.hasTable()) { 226 throw new IllegalArgumentException( 227 "Descriptor doesn't apply to a table, so we can't build it."); 228 } 229 230 // set the creation time, if one hasn't been set 231 long time = snapshot.getCreationTime(); 232 if (time == SnapshotDescriptionUtils.NO_SNAPSHOT_START_TIME_SPECIFIED) { 233 time = EnvironmentEdgeManager.currentTime(); 234 LOG.debug("Creation time not specified, setting to:" + time + " (current time:" 235 + EnvironmentEdgeManager.currentTime() + ")."); 236 SnapshotDescription.Builder builder = snapshot.toBuilder(); 237 builder.setCreationTime(time); 238 snapshot = builder.build(); 239 } 240 return snapshot; 241 } 242 243 /** 244 * Write the snapshot description into the working directory of a snapshot 245 * @param snapshot description of the snapshot being taken 246 * @param workingDir working directory of the snapshot 247 * @param fs {@link FileSystem} on which the snapshot should be taken 248 * @throws IOException if we can't reach the filesystem and the file cannot be cleaned up on 249 * failure 250 */ 251 public static void writeSnapshotInfo(SnapshotDescription snapshot, Path workingDir, FileSystem fs) 252 throws IOException { 253 FsPermission perms = FSUtils.getFilePermissions(fs, fs.getConf(), 254 HConstants.DATA_FILE_UMASK_KEY); 255 Path snapshotInfo = new Path(workingDir, SnapshotDescriptionUtils.SNAPSHOTINFO_FILE); 256 try { 257 FSDataOutputStream out = FSUtils.create(fs, snapshotInfo, perms, true); 258 try { 259 snapshot.writeTo(out); 260 } finally { 261 out.close(); 262 } 263 } catch (IOException e) { 264 // if we get an exception, try to remove the snapshot info 265 if (!fs.delete(snapshotInfo, false)) { 266 String msg = "Couldn't delete snapshot info file: " + snapshotInfo; 267 LOG.error(msg); 268 throw new IOException(msg); 269 } 270 } 271 } 272 273 /** 274 * Read in the {@link org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.SnapshotDescription} stored for the snapshot in the passed directory 275 * @param fs filesystem where the snapshot was taken 276 * @param snapshotDir directory where the snapshot was stored 277 * @return the stored snapshot description 278 * @throws CorruptedSnapshotException if the 279 * snapshot cannot be read 280 */ 281 public static SnapshotDescription readSnapshotInfo(FileSystem fs, Path snapshotDir) 282 throws CorruptedSnapshotException { 283 Path snapshotInfo = new Path(snapshotDir, SNAPSHOTINFO_FILE); 284 try { 285 FSDataInputStream in = null; 286 try { 287 in = fs.open(snapshotInfo); 288 SnapshotDescription desc = SnapshotDescription.parseFrom(in); 289 return desc; 290 } finally { 291 if (in != null) in.close(); 292 } 293 } catch (IOException e) { 294 throw new CorruptedSnapshotException("Couldn't read snapshot info from:" + snapshotInfo, e); 295 } 296 } 297 298 /** 299 * Move the finished snapshot to its final, publicly visible directory - this marks the snapshot 300 * as 'complete'. 301 * @param snapshot description of the snapshot being tabken 302 * @param rootdir root directory of the hbase installation 303 * @param workingDir directory where the in progress snapshot was built 304 * @param fs {@link FileSystem} where the snapshot was built 305 * @throws org.apache.hadoop.hbase.snapshot.SnapshotCreationException if the 306 * snapshot could not be moved 307 * @throws IOException the filesystem could not be reached 308 */ 309 public static void completeSnapshot(SnapshotDescription snapshot, Path rootdir, Path workingDir, 310 FileSystem fs) throws SnapshotCreationException, IOException { 311 Path finishedDir = getCompletedSnapshotDir(snapshot, rootdir); 312 LOG.debug("Snapshot is done, just moving the snapshot from " + workingDir + " to " 313 + finishedDir); 314 if (!fs.rename(workingDir, finishedDir)) { 315 throw new SnapshotCreationException("Failed to move working directory(" + workingDir 316 + ") to completed directory(" + finishedDir + ").", snapshot); 317 } 318 } 319 320 }