View Javadoc

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.regionserver;
19  
20  import org.apache.hadoop.classification.InterfaceAudience;
21  import org.apache.hadoop.conf.Configuration;
22  import org.apache.hadoop.hbase.HConstants;
23  import org.apache.hadoop.hbase.HTableDescriptor;
24  
25  /**
26   * A {@link RegionSplitPolicy} implementation which splits a region
27   * as soon as any of its store files exceeds a maximum configurable
28   * size.
29   * <p>
30   * This is the default split policy. From 0.94.0 on the default split policy has
31   * changed to {@link IncreasingToUpperBoundRegionSplitPolicy}
32   * </p>
33   */
34  @InterfaceAudience.Private
35  public class ConstantSizeRegionSplitPolicy extends RegionSplitPolicy {
36    private long desiredMaxFileSize;
37  
38    @Override
39    protected void configureForRegion(HRegion region) {
40      super.configureForRegion(region);
41      Configuration conf = getConf();
42      HTableDescriptor desc = region.getTableDesc();
43      if (desc != null) {
44        this.desiredMaxFileSize = desc.getMaxFileSize();
45      }
46      if (this.desiredMaxFileSize <= 0) {
47        this.desiredMaxFileSize = conf.getLong(HConstants.HREGION_MAX_FILESIZE,
48          HConstants.DEFAULT_MAX_FILE_SIZE);
49      }
50    }
51  
52    @Override
53    protected boolean shouldSplit() {
54      boolean force = region.shouldForceSplit();
55      boolean foundABigStore = false;
56  
57      for (Store store : region.getStores().values()) {
58        // If any of the stores are unable to split (eg they contain reference files)
59        // then don't split
60        if ((!store.canSplit())) {
61          return false;
62        }
63  
64        // Mark if any store is big enough
65        if (store.getSize() > desiredMaxFileSize) {
66          foundABigStore = true;
67        }
68      }
69  
70      return foundABigStore || force;
71    }
72  
73    long getDesiredMaxFileSize() {
74      return desiredMaxFileSize;
75    }
76  }