| /* |
| * 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.mapreduce; |
| |
| import com.google.common.collect.Lists; |
| import org.apache.hadoop.conf.Configuration; |
| import org.apache.hadoop.fs.Path; |
| import org.apache.hadoop.hbase.classification.InterfaceAudience; |
| import org.apache.hadoop.hbase.classification.InterfaceStability; |
| import org.apache.hadoop.hbase.client.Scan; |
| import org.apache.hadoop.mapreduce.InputSplit; |
| import org.apache.hadoop.mapreduce.JobContext; |
| |
| import java.io.IOException; |
| import java.util.Collection; |
| import java.util.List; |
| import java.util.Map; |
| |
| /** |
| * MultiTableSnapshotInputFormat generalizes |
| * {@link org.apache.hadoop.hbase.mapreduce.TableSnapshotInputFormat} |
| * allowing a MapReduce job to run over one or more table snapshots, with one or more scans |
| * configured for each. |
| * Internally, the input format delegates to |
| * {@link org.apache.hadoop.hbase.mapreduce.TableSnapshotInputFormat} |
| * and thus has the same performance advantages; |
| * see {@link org.apache.hadoop.hbase.mapreduce.TableSnapshotInputFormat} for |
| * more details. |
| * Usage is similar to TableSnapshotInputFormat, with the following exception: |
| * initMultiTableSnapshotMapperJob takes in a map |
| * from snapshot name to a collection of scans. For each snapshot in the map, each corresponding |
| * scan will be applied; |
| * the overall dataset for the job is defined by the concatenation of the regions and tables |
| * included in each snapshot/scan |
| * pair. |
| * {@link org.apache.hadoop.hbase.mapreduce.TableMapReduceUtil#initMultiTableSnapshotMapperJob |
| * (java.util.Map, Class, Class, Class, org.apache.hadoop.mapreduce.Job, boolean, org.apache |
| * .hadoop.fs.Path)} |
| * can be used to configure the job. |
| * <pre>{@code |
| * Job job = new Job(conf); |
| * Map<String, Collection<Scan>> snapshotScans = ImmutableMap.of( |
| * "snapshot1", ImmutableList.of(new Scan(Bytes.toBytes("a"), Bytes.toBytes("b"))), |
| * "snapshot2", ImmutableList.of(new Scan(Bytes.toBytes("1"), Bytes.toBytes("2"))) |
| * ); |
| * Path restoreDir = new Path("/tmp/snapshot_restore_dir") |
| * TableMapReduceUtil.initTableSnapshotMapperJob( |
| * snapshotScans, MyTableMapper.class, MyMapKeyOutput.class, |
| * MyMapOutputValueWritable.class, job, true, restoreDir); |
| * } |
| * </pre> |
| * Internally, this input format restores each snapshot into a subdirectory of the given tmp |
| * directory. Input splits and |
| * record readers are created as described in {@link org.apache.hadoop.hbase.mapreduce |
| * .TableSnapshotInputFormat} |
| * (one per region). |
| * See {@link org.apache.hadoop.hbase.mapreduce.TableSnapshotInputFormat} for more notes on |
| * permissioning; the |
| * same caveats apply here. |
| * |
| * @see org.apache.hadoop.hbase.mapreduce.TableSnapshotInputFormat |
| * @see org.apache.hadoop.hbase.client.TableSnapshotScanner |
| */ |
| @InterfaceAudience.Public |
| @InterfaceStability.Evolving |
| public class MultiTableSnapshotInputFormat extends TableSnapshotInputFormat { |
| |
| private final MultiTableSnapshotInputFormatImpl delegate; |
| |
| public MultiTableSnapshotInputFormat() { |
| this.delegate = new MultiTableSnapshotInputFormatImpl(); |
| } |
| |
| @Override |
| public List<InputSplit> getSplits(JobContext jobContext) |
| throws IOException, InterruptedException { |
| List<TableSnapshotInputFormatImpl.InputSplit> splits = |
| delegate.getSplits(jobContext.getConfiguration()); |
| List<InputSplit> rtn = Lists.newArrayListWithCapacity(splits.size()); |
| |
| for (TableSnapshotInputFormatImpl.InputSplit split : splits) { |
| rtn.add(new TableSnapshotInputFormat.TableSnapshotRegionSplit(split)); |
| } |
| |
| return rtn; |
| } |
| |
| public static void setInput(Configuration configuration, |
| Map<String, Collection<Scan>> snapshotScans, Path tmpRestoreDir) throws IOException { |
| new MultiTableSnapshotInputFormatImpl().setInput(configuration, snapshotScans, tmpRestoreDir); |
| } |
| } |