hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/IncreasingToUpperBoundRegionSplitPolicy.java

   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 java.io.IOException;
  21 import java.util.List;
  22
  23 import org.apache.hadoop.conf.Configuration;
  24 import org.apache.hadoop.hbase.HConstants;
  25 import org.apache.hadoop.hbase.TableName;
  26 import org.apache.yetus.audience.InterfaceAudience;
  27 import org.slf4j.Logger;
  28 import org.slf4j.LoggerFactory;
  29 import org.apache.hadoop.hbase.client.TableDescriptor;
  30 import org.apache.hadoop.hbase.client.TableDescriptorBuilder;
  31
  32 /**
  33  * Split size is the number of regions that are on this server that all are
  34  * of the same table, cubed, times 2x the region flush size OR the maximum
  35  * region split size, whichever is smaller.
  36  * <p>
  37  * For example, if the flush size is 128MB, then after two flushes (256MB) we
  38  * will split which will make two regions that will split when their size is
  39  * {@code 2^3 * 128MB*2 = 2048MB}.
  40  * <p>
  41  * If one of these regions splits, then there are three regions and now the
  42  * split size is {@code 3^3 * 128MB*2 = 6912MB}, and so on until we reach the configured
  43  * maximum file size and then from there on out, we'll use that.
  44  */
  45 @InterfaceAudience.Private
  46 public class IncreasingToUpperBoundRegionSplitPolicy extends ConstantSizeRegionSplitPolicy {
  47   private static final Logger LOG =
  48       LoggerFactory.getLogger(IncreasingToUpperBoundRegionSplitPolicy.class);
  49
  50   protected long initialSize;
  51
  52   @Override
  53   public String toString() {
  54     return "IncreasingToUpperBoundRegionSplitPolicy{" + "initialSize=" + initialSize +
  55       ", " + super.toString() + '}';
  56   }
  57
  58   @Override
  59   protected void configureForRegion(HRegion region) {
  60     super.configureForRegion(region);
  61     Configuration conf = getConf();
  62     initialSize = conf.getLong("hbase.increasing.policy.initial.size", -1);
  63     if (initialSize > 0) {
  64       return;
  65     }
  66     TableDescriptor desc = region.getTableDescriptor();
  67     if (desc != null) {
  68       initialSize = 2 * desc.getMemStoreFlushSize();
  69     }
  70     if (initialSize <= 0) {
  71       initialSize = 2 * conf.getLong(HConstants.HREGION_MEMSTORE_FLUSH_SIZE,
  72                                      TableDescriptorBuilder.DEFAULT_MEMSTORE_FLUSH_SIZE);
  73     }
  74   }
  75
  76   @Override
  77   protected boolean shouldSplit() {
  78     if (!canSplit()) {
  79       return false;
  80     }
  81     // Get count of regions that have the same common table as this.region
  82     int tableRegionsCount = getCountOfCommonTableRegions();
  83     // Get size to check
  84     long sizeToCheck = getSizeToCheck(tableRegionsCount);
  85     boolean shouldSplit = isExceedSize(sizeToCheck);
  86     if (shouldSplit) {
  87       LOG.debug("regionsWithCommonTable={}", tableRegionsCount);
  88     }
  89     return shouldSplit;
  90   }
  91
  92   /**
  93    * @return Count of regions on this server that share the table this.region
  94    * belongs to
  95    */
  96   private int getCountOfCommonTableRegions() {
  97     RegionServerServices rss = region.getRegionServerServices();
  98     // Can be null in tests
  99     if (rss == null) {
 100       return 0;
 101     }
 102     TableName tablename = region.getTableDescriptor().getTableName();
 103     int tableRegionsCount = 0;
 104     try {
 105       List<? extends Region> hri = rss.getRegions(tablename);
 106       tableRegionsCount = hri == null || hri.isEmpty() ? 0 : hri.size();
 107     } catch (IOException e) {
 108       LOG.debug("Failed getOnlineRegions " + tablename, e);
 109     }
 110     return tableRegionsCount;
 111   }
 112
 113   /**
 114    * @return Region max size or {@code count of regions cubed * 2 * flushsize},
 115    * which ever is smaller; guard against there being zero regions on this server.
 116    */
 117   protected long getSizeToCheck(final int tableRegionsCount) {
 118     // safety check for 100 to avoid numerical overflow in extreme cases
 119     return tableRegionsCount == 0 || tableRegionsCount > 100
 120                ? getDesiredMaxFileSize()
 121                : Math.min(getDesiredMaxFileSize(),
 122                           initialSize * tableRegionsCount * tableRegionsCount * tableRegionsCount);
 123   }
 124
 125 }