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.regionserver;
019
020import java.io.IOException;
021import java.util.List;
022import org.apache.hadoop.conf.Configuration;
023import org.apache.hadoop.hbase.HConstants;
024import org.apache.hadoop.hbase.TableName;
025import org.apache.hadoop.hbase.client.RegionInfo;
026import org.apache.hadoop.hbase.client.TableDescriptor;
027import org.apache.hadoop.hbase.client.TableDescriptorBuilder;
028import org.apache.yetus.audience.InterfaceAudience;
029import org.slf4j.Logger;
030import org.slf4j.LoggerFactory;
031
032/**
033 * Split size is the number of regions that are on this server that all are of the same table,
034 * cubed, times 2x the region flush size OR the maximum region split size, whichever is smaller.
035 * <p>
036 * For example, if the flush size is 128MB, then after two flushes (256MB) we will split which will
037 * make two regions that will split when their size is {@code 2^3 * 128MB*2 = 2048MB}.
038 * <p>
039 * If one of these regions splits, then there are three regions and now the split size is
040 * {@code 3^3 * 128MB*2 = 6912MB}, and so on until we reach the configured maximum file size and
041 * then from there on out, we'll use that.
042 */
043@InterfaceAudience.Private
044public class IncreasingToUpperBoundRegionSplitPolicy extends ConstantSizeRegionSplitPolicy {
045  private static final Logger LOG =
046    LoggerFactory.getLogger(IncreasingToUpperBoundRegionSplitPolicy.class);
047
048  protected long initialSize;
049
050  @Override
051  public String toString() {
052    return "IncreasingToUpperBoundRegionSplitPolicy{" + "initialSize=" + initialSize + ", "
053      + super.toString() + '}';
054  }
055
056  @Override
057  protected void configureForRegion(HRegion region) {
058    super.configureForRegion(region);
059    Configuration conf = getConf();
060    initialSize = conf.getLong("hbase.increasing.policy.initial.size", -1);
061    if (initialSize > 0) {
062      return;
063    }
064    TableDescriptor desc = region.getTableDescriptor();
065    if (desc != null) {
066      initialSize = 2 * desc.getMemStoreFlushSize();
067    }
068    if (initialSize <= 0) {
069      initialSize = 2 * conf.getLong(HConstants.HREGION_MEMSTORE_FLUSH_SIZE,
070        TableDescriptorBuilder.DEFAULT_MEMSTORE_FLUSH_SIZE);
071    }
072  }
073
074  @Override
075  protected boolean shouldSplit() {
076    if (!canSplit()) {
077      return false;
078    }
079    // Get count of regions that have the same common table as this.region
080    int tableRegionsCount = getCountOfCommonTableRegions();
081    // Get size to check
082    long sizeToCheck = getSizeToCheck(tableRegionsCount);
083    boolean shouldSplit = isExceedSize(sizeToCheck);
084    if (shouldSplit) {
085      LOG.debug("regionsWithCommonTable={}", tableRegionsCount);
086    }
087    return shouldSplit;
088  }
089
090  /** Returns Count of regions on this server that share the table this.region belongs to */
091  private int getCountOfCommonTableRegions() {
092    RegionServerServices rss = region.getRegionServerServices();
093    // Can be null in tests
094    if (rss == null) {
095      return 0;
096    }
097    TableName tablename = region.getTableDescriptor().getTableName();
098    int tableRegionsCount = 0;
099    try {
100      List<? extends Region> hri = rss.getRegions(tablename);
101      if (hri != null && !hri.isEmpty()) {
102        tableRegionsCount = (int) hri.stream()
103          .filter(r -> r.getRegionInfo().getReplicaId() == RegionInfo.DEFAULT_REPLICA_ID).count();
104      }
105    } catch (IOException e) {
106      LOG.debug("Failed getOnlineRegions " + tablename, e);
107    }
108    return tableRegionsCount;
109  }
110
111  /**
112   * @return Region max size or {@code count of regions cubed * 2 * flushsize}, which ever is
113   *         smaller; guard against there being zero regions on this server.
114   */
115  protected long getSizeToCheck(final int tableRegionsCount) {
116    // safety check for 100 to avoid numerical overflow in extreme cases
117    return tableRegionsCount == 0 || tableRegionsCount > 100
118      ? getDesiredMaxFileSize()
119      : Math.min(getDesiredMaxFileSize(),
120        initialSize * tableRegionsCount * tableRegionsCount * tableRegionsCount);
121  }
122
123}