Source code

001/*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package org.apache.hadoop.hbase.io.hfile;
019
020import static org.apache.hadoop.hbase.HConstants.BUCKET_CACHE_IOENGINE_KEY;
021import static org.apache.hadoop.hbase.HConstants.BUCKET_CACHE_PERSISTENT_PATH_KEY;
022import static org.apache.hadoop.hbase.HConstants.BUCKET_CACHE_SIZE_KEY;
023
024import java.io.IOException;
025import java.util.Map;
026import java.util.concurrent.ForkJoinPool;
027import org.apache.hadoop.conf.Configuration;
028import org.apache.hadoop.hbase.HConstants;
029import org.apache.hadoop.hbase.io.hfile.bucket.BucketCache;
030import org.apache.hadoop.hbase.io.util.MemorySizeUtil;
031import org.apache.hadoop.hbase.regionserver.HRegion;
032import org.apache.hadoop.hbase.util.ReflectionUtils;
033import org.apache.hadoop.util.StringUtils;
034import org.apache.yetus.audience.InterfaceAudience;
035import org.slf4j.Logger;
036import org.slf4j.LoggerFactory;
037
038@InterfaceAudience.Private
039public final class BlockCacheFactory {
040
041  private static final Logger LOG = LoggerFactory.getLogger(BlockCacheFactory.class.getName());
042
043  /**
044   * Configuration keys for Bucket cache
045   */
046
047  /**
048   * Configuration key to cache block policy (Lru, TinyLfu, AdaptiveLRU, IndexOnlyLRU).
049   */
050  public static final String BLOCKCACHE_POLICY_KEY = "hfile.block.cache.policy";
051  public static final String BLOCKCACHE_POLICY_DEFAULT = "LRU";
052
053  public static final String BUCKET_CACHE_WRITER_THREADS_KEY = "hbase.bucketcache.writer.threads";
054
055  public static final String BUCKET_CACHE_WRITER_QUEUE_KEY = "hbase.bucketcache.writer.queuelength";
056
057  /**
058   * A comma-delimited array of values for use as bucket sizes.
059   */
060  public static final String BUCKET_CACHE_BUCKETS_KEY = "hbase.bucketcache.bucket.sizes";
061
062  /**
063   * Defaults for Bucket cache
064   */
065  public static final int DEFAULT_BUCKET_CACHE_WRITER_THREADS = 3;
066  public static final int DEFAULT_BUCKET_CACHE_WRITER_QUEUE = 64;
067
068  /**
069   * The target block size used by blockcache instances. Defaults to
070   * {@link HConstants#DEFAULT_BLOCKSIZE}.
071   */
072  public static final String BLOCKCACHE_BLOCKSIZE_KEY = "hbase.blockcache.minblocksize";
073
074  private static final String EXTERNAL_BLOCKCACHE_KEY = "hbase.blockcache.use.external";
075  private static final boolean EXTERNAL_BLOCKCACHE_DEFAULT = false;
076
077  private static final String EXTERNAL_BLOCKCACHE_CLASS_KEY = "hbase.blockcache.external.class";
078
079  /**
080   * @deprecated use {@link BlockCacheFactory#BLOCKCACHE_BLOCKSIZE_KEY} instead.
081   */
082  @Deprecated
083  static final String DEPRECATED_BLOCKCACHE_BLOCKSIZE_KEY = "hbase.offheapcache.minblocksize";
084
085  private BlockCacheFactory() {
086  }
087
088  public static BlockCache createBlockCache(Configuration conf,
089    Map<String, HRegion> onlineRegions) {
090    FirstLevelBlockCache l1Cache = createFirstLevelCache(conf);
091    if (l1Cache == null) {
092      return null;
093    }
094    boolean useExternal = conf.getBoolean(EXTERNAL_BLOCKCACHE_KEY, EXTERNAL_BLOCKCACHE_DEFAULT);
095    if (useExternal) {
096      BlockCache l2CacheInstance = createExternalBlockcache(conf);
097      return l2CacheInstance == null
098        ? l1Cache
099        : new InclusiveCombinedBlockCache(l1Cache, l2CacheInstance);
100    } else {
101      // otherwise use the bucket cache.
102      BucketCache bucketCache = createBucketCache(conf, onlineRegions);
103      if (!conf.getBoolean("hbase.bucketcache.combinedcache.enabled", true)) {
104        // Non combined mode is off from 2.0
105        LOG.warn(
106          "From HBase 2.0 onwards only combined mode of LRU cache and bucket cache is available");
107      }
108      return bucketCache == null ? l1Cache : new CombinedBlockCache(l1Cache, bucketCache);
109    }
110  }
111
112  public static BlockCache createBlockCache(Configuration conf) {
113    return createBlockCache(conf, null);
114  }
115
116  private static FirstLevelBlockCache createFirstLevelCache(final Configuration c) {
117    final long cacheSize = MemorySizeUtil.getOnHeapCacheSize(c);
118    if (cacheSize < 0) {
119      return null;
120    }
121    String policy = c.get(BLOCKCACHE_POLICY_KEY, BLOCKCACHE_POLICY_DEFAULT);
122    int blockSize = c.getInt(BLOCKCACHE_BLOCKSIZE_KEY, HConstants.DEFAULT_BLOCKSIZE);
123    LOG.info("Allocating BlockCache size=" + StringUtils.byteDesc(cacheSize) + ", blockSize="
124      + StringUtils.byteDesc(blockSize));
125    if (policy.equalsIgnoreCase("LRU")) {
126      return new LruBlockCache(cacheSize, blockSize, true, c);
127    } else if (policy.equalsIgnoreCase("IndexOnlyLRU")) {
128      return new IndexOnlyLruBlockCache(cacheSize, blockSize, true, c);
129    } else if (policy.equalsIgnoreCase("TinyLFU")) {
130      return new TinyLfuBlockCache(cacheSize, blockSize, ForkJoinPool.commonPool(), c);
131    } else if (policy.equalsIgnoreCase("AdaptiveLRU")) {
132      return new LruAdaptiveBlockCache(cacheSize, blockSize, true, c);
133    } else {
134      throw new IllegalArgumentException("Unknown policy: " + policy);
135    }
136  }
137
138  /**
139   * Enum of all built in external block caches. This is used for config.
140   */
141  private static enum ExternalBlockCaches {
142    memcached("org.apache.hadoop.hbase.io.hfile.MemcachedBlockCache");
143
144    // TODO(eclark): Consider more. Redis, etc.
145    Class<? extends BlockCache> clazz;
146
147    ExternalBlockCaches(String clazzName) {
148      try {
149        clazz = (Class<? extends BlockCache>) Class.forName(clazzName);
150      } catch (ClassNotFoundException cnef) {
151        clazz = null;
152      }
153    }
154
155    ExternalBlockCaches(Class<? extends BlockCache> clazz) {
156      this.clazz = clazz;
157    }
158  }
159
160  private static BlockCache createExternalBlockcache(Configuration c) {
161    if (LOG.isDebugEnabled()) {
162      LOG.debug("Trying to use External l2 cache");
163    }
164    Class klass = null;
165
166    // Get the class, from the config. s
167    try {
168      klass = ExternalBlockCaches.valueOf(c.get(EXTERNAL_BLOCKCACHE_CLASS_KEY, "memcache")).clazz;
169    } catch (IllegalArgumentException exception) {
170      try {
171        klass = c.getClass(EXTERNAL_BLOCKCACHE_CLASS_KEY,
172          Class.forName("org.apache.hadoop.hbase.io.hfile.MemcachedBlockCache"));
173      } catch (ClassNotFoundException e) {
174        return null;
175      }
176    }
177
178    // Now try and create an instance of the block cache.
179    try {
180      LOG.info("Creating external block cache of type: " + klass);
181      return (BlockCache) ReflectionUtils.newInstance(klass, c);
182    } catch (Exception e) {
183      LOG.warn("Error creating external block cache", e);
184    }
185    return null;
186
187  }
188
189  private static BucketCache createBucketCache(Configuration c,
190    Map<String, HRegion> onlineRegions) {
191    // Check for L2. ioengine name must be non-null.
192    String bucketCacheIOEngineName = c.get(BUCKET_CACHE_IOENGINE_KEY, null);
193    if (bucketCacheIOEngineName == null || bucketCacheIOEngineName.length() <= 0) {
194      return null;
195    }
196
197    int blockSize = c.getInt(BLOCKCACHE_BLOCKSIZE_KEY, HConstants.DEFAULT_BLOCKSIZE);
198    final long bucketCacheSize = MemorySizeUtil.getBucketCacheSize(c);
199    if (bucketCacheSize <= 0) {
200      throw new IllegalStateException("bucketCacheSize <= 0; Check " + BUCKET_CACHE_SIZE_KEY
201        + " setting and/or server java heap size");
202    }
203    if (c.get("hbase.bucketcache.percentage.in.combinedcache") != null) {
204      LOG.warn("Configuration 'hbase.bucketcache.percentage.in.combinedcache' is no longer "
205        + "respected. See comments in http://hbase.apache.org/book.html#_changes_of_note");
206    }
207    int writerThreads =
208      c.getInt(BUCKET_CACHE_WRITER_THREADS_KEY, DEFAULT_BUCKET_CACHE_WRITER_THREADS);
209    int writerQueueLen = c.getInt(BUCKET_CACHE_WRITER_QUEUE_KEY, DEFAULT_BUCKET_CACHE_WRITER_QUEUE);
210    String persistentPath = c.get(BUCKET_CACHE_PERSISTENT_PATH_KEY);
211    String[] configuredBucketSizes = c.getStrings(BUCKET_CACHE_BUCKETS_KEY);
212    int[] bucketSizes = null;
213    if (configuredBucketSizes != null) {
214      bucketSizes = new int[configuredBucketSizes.length];
215      for (int i = 0; i < configuredBucketSizes.length; i++) {
216        int bucketSize = Integer.parseInt(configuredBucketSizes[i].trim());
217        if (bucketSize % 256 != 0) {
218          // We need all the bucket sizes to be multiples of 256. Having all the configured bucket
219          // sizes to be multiples of 256 will ensure that the block offsets within buckets,
220          // that are calculated, will also be multiples of 256.
221          // See BucketEntry where offset to each block is represented using 5 bytes (instead of 8
222          // bytes long). We would like to save heap overhead as less as possible.
223          throw new IllegalArgumentException("Illegal value: " + bucketSize + " configured for '"
224            + BUCKET_CACHE_BUCKETS_KEY + "'. All bucket sizes to be multiples of 256");
225        }
226        bucketSizes[i] = bucketSize;
227      }
228    }
229    BucketCache bucketCache = null;
230    try {
231      int ioErrorsTolerationDuration =
232        c.getInt("hbase.bucketcache.ioengine.errors.tolerated.duration",
233          BucketCache.DEFAULT_ERROR_TOLERATION_DURATION);
234      // Bucket cache logs its stats on creation internal to the constructor.
235      bucketCache = new BucketCache(bucketCacheIOEngineName, bucketCacheSize, blockSize,
236        bucketSizes, writerThreads, writerQueueLen, persistentPath, ioErrorsTolerationDuration, c,
237        onlineRegions);
238    } catch (IOException ioex) {
239      LOG.error("Can't instantiate bucket cache", ioex);
240      throw new RuntimeException(ioex);
241    }
242    return bucketCache;
243  }
244}