| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package org.apache.hadoop.hbase.regionserver; |
| |
| import java.io.IOException; |
| import java.util.List; |
| import java.util.Optional; |
| import org.apache.hadoop.conf.Configuration; |
| import org.apache.hadoop.conf.Configured; |
| import org.apache.hadoop.hbase.HBaseInterfaceAudience; |
| import org.apache.hadoop.hbase.HConstants; |
| import org.apache.hadoop.hbase.client.TableDescriptor; |
| import org.apache.hadoop.util.ReflectionUtils; |
| import org.apache.yetus.audience.InterfaceAudience; |
| |
| import org.apache.hbase.thirdparty.com.google.common.base.Preconditions; |
| |
| /** |
| * A split policy determines when a Region should be split. |
| * @see SteppingSplitPolicy Default split policy since 2.0.0 |
| * @see IncreasingToUpperBoundRegionSplitPolicy Default split policy since 0.94.0 |
| * @see ConstantSizeRegionSplitPolicy Default split policy before 0.94.0 |
| */ |
| @InterfaceAudience.LimitedPrivate(HBaseInterfaceAudience.CONFIG) |
| public abstract class RegionSplitPolicy extends Configured { |
| private static final Class<? extends RegionSplitPolicy> DEFAULT_SPLIT_POLICY_CLASS = |
| SteppingSplitPolicy.class; |
| |
| /** |
| * The region configured for this split policy. As of hbase-2.0.0, RegionSplitPolicy can be |
| * instantiated on the Master-side so the Phoenix local-indexer can block default hbase behavior. |
| * This is an exotic usage. Should not trouble any other users of RegionSplitPolicy. |
| */ |
| protected HRegion region; |
| |
| /** |
| * Upon construction, this method will be called with the region to be governed. It will be called |
| * once and only once. |
| */ |
| protected void configureForRegion(HRegion region) { |
| Preconditions.checkState(this.region == null, "Policy already configured for region {}", |
| this.region); |
| |
| this.region = region; |
| } |
| |
| /** Returns true if the specified region should be split. */ |
| protected abstract boolean shouldSplit(); |
| |
| /** Returns {@code true} if the specified region can be split. */ |
| protected boolean canSplit() { |
| return !region.getRegionInfo().isMetaRegion() && region.isAvailable() |
| && region.getStores().stream().allMatch(HStore::canSplit); |
| } |
| |
| /** |
| * @return the key at which the region should be split, or null if it cannot be split. This will |
| * only be called if shouldSplit previously returned true. |
| */ |
| protected byte[] getSplitPoint() { |
| List<HStore> stores = region.getStores(); |
| |
| byte[] splitPointFromLargestStore = null; |
| long largestStoreSize = 0; |
| for (HStore s : stores) { |
| Optional<byte[]> splitPoint = s.getSplitPoint(); |
| // Store also returns null if it has references as way of indicating it is not splittable |
| long storeSize = s.getSize(); |
| if (splitPoint.isPresent() && largestStoreSize < storeSize) { |
| splitPointFromLargestStore = splitPoint.get(); |
| largestStoreSize = storeSize; |
| } |
| } |
| |
| return splitPointFromLargestStore; |
| } |
| |
| /** |
| * Create the RegionSplitPolicy configured for the given table. |
| * @return a RegionSplitPolicy |
| */ |
| public static RegionSplitPolicy create(HRegion region, Configuration conf) throws IOException { |
| Preconditions.checkNotNull(region, "Region should not be null."); |
| Class<? extends RegionSplitPolicy> clazz = |
| getSplitPolicyClass(region.getTableDescriptor(), conf); |
| RegionSplitPolicy policy = ReflectionUtils.newInstance(clazz, conf); |
| policy.configureForRegion(region); |
| return policy; |
| } |
| |
| public static Class<? extends RegionSplitPolicy> getSplitPolicyClass(TableDescriptor htd, |
| Configuration conf) throws IOException { |
| String className = htd.getRegionSplitPolicyClassName(); |
| if (className == null) { |
| className = |
| conf.get(HConstants.HBASE_REGION_SPLIT_POLICY_KEY, DEFAULT_SPLIT_POLICY_CLASS.getName()); |
| } |
| |
| try { |
| Class<? extends RegionSplitPolicy> clazz = |
| Class.forName(className).asSubclass(RegionSplitPolicy.class); |
| return clazz; |
| } catch (Exception e) { |
| throw new IOException("Unable to load configured region split policy '" + className |
| + "' for table '" + htd.getTableName() + "'", e); |
| } |
| } |
| |
| /** |
| * In |
| * {@link HRegionFileSystem#splitStoreFile(org.apache.hadoop.hbase.client.RegionInfo, String, HStoreFile, byte[], boolean, RegionSplitPolicy)} |
| * we are not creating the split reference if split row does not lie inside the StoreFile range. |
| * But in some use cases we may need to create the split reference even when the split row does |
| * not lie inside the StoreFile range. This method can be used to decide, whether to skip the the |
| * StoreFile range check or not. |
| * <p> |
| * This method is not for general use. It is a mechanism put in place by Phoenix local indexing to |
| * defeat standard hbase behaviors. Phoenix local indices are very likely the only folks who would |
| * make use of this method. On the Master-side, we will instantiate a RegionSplitPolicy instance |
| * and run this method ONLY... none of the others make sense on the Master-side. |
| * </p> |
| * TODO: Shutdown this phoenix specialization or do it via some other means. |
| * @return whether to skip the StoreFile range check or not |
| */ |
| protected boolean skipStoreFileRangeCheck(String familyName) { |
| return false; |
| } |
| } |