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.storefiletracker;
019
020import java.io.IOException;
021import java.util.Collection;
022import java.util.List;
023import org.apache.hadoop.fs.FileStatus;
024import org.apache.hadoop.fs.Path;
025import org.apache.hadoop.hbase.TableName;
026import org.apache.hadoop.hbase.client.TableDescriptorBuilder;
027import org.apache.hadoop.hbase.io.Reference;
028import org.apache.hadoop.hbase.regionserver.CreateStoreFileWriterParams;
029import org.apache.hadoop.hbase.regionserver.HStoreFile;
030import org.apache.hadoop.hbase.regionserver.StoreContext;
031import org.apache.hadoop.hbase.regionserver.StoreFileInfo;
032import org.apache.hadoop.hbase.regionserver.StoreFileWriter;
033import org.apache.yetus.audience.InterfaceAudience;
034
035/**
036 * An interface to define how we track the store files for a give store.
037 * <p/>
038 * In the old time, we will write store to a tmp directory first, and then rename it to the actual
039 * data file. And once a store file is under data directory, we will consider it as 'committed'. And
040 * we need to do listing when loading store files.
041 * <p/>
042 * When cloud age is coming, now we want to store the store files on object storage, where rename
043 * and list are not as cheap as on HDFS, especially rename. Although introducing a metadata
044 * management layer for object storage could solve the problem, but we still want HBase to run on
045 * pure object storage, so here we introduce this interface to abstract how we track the store
046 * files. For the old implementation, we just persist nothing here, and do listing to load store
047 * files. When running on object storage, we could persist the store file list in a system region,
048 * or in a file on the object storage, to make it possible to write directly into the data directory
049 * to avoid renaming, and also avoid listing when loading store files.
050 * <p/>
051 * The implementation requires to be thread safe as flush and compaction may occur as the same time,
052 * and we could also do multiple compactions at the same time. As the implementation may choose to
053 * persist the store file list to external storage, which could be slow, it is the duty for the
054 * callers to not call it inside a lock which may block normal read/write requests.
055 */
056@InterfaceAudience.Private
057public interface StoreFileTracker {
058  /**
059   * Load the store files list when opening a region.
060   */
061  List<StoreFileInfo> load() throws IOException;
062
063  /**
064   * Add new store files.
065   * <p/>
066   * Used for flush and bulk load.
067   */
068  void add(Collection<StoreFileInfo> newFiles) throws IOException;
069
070  /**
071   * Add new store files and remove compacted store files after compaction.
072   */
073  void replace(Collection<StoreFileInfo> compactedFiles, Collection<StoreFileInfo> newFiles)
074    throws IOException;
075
076  /**
077   * Set the store files.
078   */
079  void set(List<StoreFileInfo> files) throws IOException;
080
081  /**
082   * Create a writer for writing new store files.
083   * @return Writer for a new StoreFile
084   */
085  StoreFileWriter createWriter(CreateStoreFileWriterParams params) throws IOException;
086
087  /**
088   * Adds StoreFileTracker implementations specific configurations into the table descriptor.
089   * <p/>
090   * This is used to avoid accidentally data loss when changing the cluster level store file tracker
091   * implementation, and also possible misconfiguration between master and region servers.
092   * <p/>
093   * See HBASE-26246 for more details.
094   * @param builder The table descriptor builder for the given table.
095   */
096  TableDescriptorBuilder updateWithTrackerConfigs(TableDescriptorBuilder builder);
097
098  /**
099   * Whether the implementation of this tracker requires you to write to temp directory first, i.e,
100   * does not allow broken store files under the actual data directory.
101   */
102  boolean requireWritingToTmpDirFirst();
103
104  Reference createReference(Reference reference, Path path) throws IOException;
105
106  /**
107   * Reads the reference file from the given path.
108   * @param path the {@link Path} to the reference file in the file system.
109   * @return a {@link Reference} that points at top/bottom half of a an hfile
110   */
111  Reference readReference(Path path) throws IOException;
112
113  /**
114   * Returns true if the specified family has reference files
115   * @return true if family contains reference files
116   */
117  boolean hasReferences() throws IOException;
118
119  StoreFileInfo getStoreFileInfo(final FileStatus fileStatus, final Path initialPath,
120    final boolean primaryReplica) throws IOException;
121
122  StoreFileInfo getStoreFileInfo(final Path initialPath, final boolean primaryReplica)
123    throws IOException;
124
125  /**
126   * Create a new HFileLink
127   * <p>
128   * It also adds a back-reference to the hfile back-reference directory to simplify the
129   * reference-count and the cleaning process.
130   * @param hfileLinkName - HFileLink name (it contains hfile-region-table)
131   * @param createBackRef - Whether back reference should be created. Defaults to true.
132   * @return the file link name.
133   * @throws IOException on file or parent directory creation failure.
134   */
135  String createHFileLink(final TableName linkedTable, final String linkedRegion,
136    final String hfileName, final boolean createBackRef) throws IOException;
137
138  /**
139   * Create a new HFileLink starting from a hfileLink name
140   * <p>
141   * It also adds a back-reference to the hfile back-reference directory to simplify the
142   * reference-count and the cleaning process.
143   * @param hfileLinkName - HFileLink name (it contains hfile-region-table)
144   * @param createBackRef - Whether back reference should be created. Defaults to true.
145   * @return the file link name.
146   * @throws IOException on file or parent directory creation failure.
147   */
148  String createFromHFileLink(final String hfileName, final boolean createBackRef)
149    throws IOException;
150
151  /**
152   * Closes and archives the specified store files from the specified family.
153   * @param storeFiles set of store files to remove
154   * @throws IOException if the archiving fails
155   */
156  void removeStoreFiles(List<HStoreFile> storeFiles) throws IOException;
157
158  /**
159   * Get the store context. Get the store context.
160   * @return the store context.
161   */
162  StoreContext getStoreContext();
163}