All Downloads are FREE. Search and download functionalities are using the official Maven repository.

org.apache.hadoop.hbase.mapreduce.WALPlayer Maven / Gradle / Ivy

There is a newer version: 3.0.0-beta-1
Show newest version
/**
 * 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 org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hbase.Cell;
import org.apache.hadoop.hbase.CellUtil;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.KeyValue;
import org.apache.hadoop.hbase.KeyValueUtil;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.classification.InterfaceAudience;
import org.apache.hadoop.hbase.classification.InterfaceStability;
import org.apache.hadoop.hbase.client.Connection;
import org.apache.hadoop.hbase.client.ConnectionFactory;
import org.apache.hadoop.hbase.client.Delete;
import org.apache.hadoop.hbase.client.Mutation;
import org.apache.hadoop.hbase.client.Put;
import org.apache.hadoop.hbase.client.RegionLocator;
import org.apache.hadoop.hbase.client.Table;
import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
import org.apache.hadoop.hbase.regionserver.wal.WALCellCodec;
import org.apache.hadoop.hbase.regionserver.wal.WALEdit;
import org.apache.hadoop.hbase.util.Bytes;
import org.apache.hadoop.hbase.wal.WALKey;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.util.GenericOptionsParser;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;

import java.io.IOException;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Map;
import java.util.TreeMap;

/**
 * A tool to replay WAL files as a M/R job.
 * The WAL can be replayed for a set of tables or all tables,
 * and a timerange can be provided (in milliseconds).
 * The WAL is filtered to the passed set of tables and  the output
 * can optionally be mapped to another set of tables.
 *
 * WAL replay can also generate HFiles for later bulk importing,
 * in that case the WAL is replayed for a single table only.
 */
@InterfaceAudience.Public
@InterfaceStability.Stable
public class WALPlayer extends Configured implements Tool {
  private static final Log LOG = LogFactory.getLog(WALPlayer.class);
  final static String NAME = "WALPlayer";
  final static String BULK_OUTPUT_CONF_KEY = "wal.bulk.output";
  final static String TABLES_KEY = "wal.input.tables";
  final static String TABLE_MAP_KEY = "wal.input.tablesmap";

  // This relies on Hadoop Configuration to handle warning about deprecated configs and
  // to set the correct non-deprecated configs when an old one shows up.
  static {
    Configuration.addDeprecation("hlog.bulk.output", BULK_OUTPUT_CONF_KEY);
    Configuration.addDeprecation("hlog.input.tables", TABLES_KEY);
    Configuration.addDeprecation("hlog.input.tablesmap", TABLE_MAP_KEY);
    Configuration.addDeprecation(HLogInputFormat.START_TIME_KEY, WALInputFormat.START_TIME_KEY);
    Configuration.addDeprecation(HLogInputFormat.END_TIME_KEY, WALInputFormat.END_TIME_KEY);
  }

  /**
   * A mapper that just writes out KeyValues.
   * This one can be used together with {@link KeyValueSortReducer}
   */
  static class WALKeyValueMapper
  extends Mapper {
    private byte[] table;

    @Override
    public void map(WALKey key, WALEdit value,
      Context context)
    throws IOException {
      try {
        // skip all other tables
        if (Bytes.equals(table, key.getTablename().getName())) {
          for (Cell cell : value.getCells()) {
            KeyValue kv = KeyValueUtil.ensureKeyValueTypeForMR(cell);
            if (WALEdit.isMetaEditFamily(kv.getFamily())) continue;
            context.write(new ImmutableBytesWritable(kv.getRow()), kv);
          }
        }
      } catch (InterruptedException e) {
        e.printStackTrace();
      }
    }

    @Override
    public void setup(Context context) throws IOException {
      // only a single table is supported when HFiles are generated with HFileOutputFormat
      String tables[] = context.getConfiguration().getStrings(TABLES_KEY);
      if (tables == null || tables.length != 1) {
        // this can only happen when WALMapper is used directly by a class other than WALPlayer
        throw new IOException("Exactly one table must be specified for bulk HFile case.");
      }
      table = Bytes.toBytes(tables[0]);
    }
  }

  /**
   * A mapper that writes out {@link Mutation} to be directly applied to
   * a running HBase instance.
   */
  protected static class WALMapper
  extends Mapper {
    private Map tables = new TreeMap();

    @Override
    public void map(WALKey key, WALEdit value, Context context)
    throws IOException {
      try {
        if (tables.isEmpty() || tables.containsKey(key.getTablename())) {
          TableName targetTable = tables.isEmpty() ?
                key.getTablename() :
                tables.get(key.getTablename());
          ImmutableBytesWritable tableOut = new ImmutableBytesWritable(targetTable.getName());
          Put put = null;
          Delete del = null;
          Cell lastCell = null;
          for (Cell cell : value.getCells()) {
            // filtering WAL meta entries
            if (WALEdit.isMetaEditFamily(cell.getFamily())) continue;

            // Allow a subclass filter out this cell.
            if (filter(context, cell)) {
              // A WALEdit may contain multiple operations (HBASE-3584) and/or
              // multiple rows (HBASE-5229).
              // Aggregate as much as possible into a single Put/Delete
              // operation before writing to the context.
              if (lastCell == null || lastCell.getTypeByte() != cell.getTypeByte()
                  || !CellUtil.matchingRow(lastCell, cell)) {
                // row or type changed, write out aggregate KVs.
                if (put != null) context.write(tableOut, put);
                if (del != null) context.write(tableOut, del);
                if (CellUtil.isDelete(cell)) {
                  del = new Delete(cell.getRow());
                } else {
                  put = new Put(cell.getRow());
                }
              }
              if (CellUtil.isDelete(cell)) {
                del.addDeleteMarker(cell);
              } else {
                put.add(cell);
              }
            }
            lastCell = cell;
          }
          // write residual KVs
          if (put != null) context.write(tableOut, put);
          if (del != null) context.write(tableOut, del);
        }
      } catch (InterruptedException e) {
        e.printStackTrace();
      }
    }

    /**
     * @param cell
     * @return Return true if we are to emit this cell.
     */
    protected boolean filter(Context context, final Cell cell) {
      return true;
    }

    @Override
    public void setup(Context context) throws IOException {
      String[] tableMap = context.getConfiguration().getStrings(TABLE_MAP_KEY);
      String[] tablesToUse = context.getConfiguration().getStrings(TABLES_KEY);
      if (tablesToUse == null && tableMap == null) {
        // Then user wants all tables.
      } else if (tablesToUse == null || tableMap == null || tablesToUse.length != tableMap.length) {
        // this can only happen when WALMapper is used directly by a class other than WALPlayer
        throw new IOException("No tables or incorrect table mapping specified.");
      }
      int i = 0;
      if (tablesToUse != null) {
        for (String table : tablesToUse) {
          tables.put(TableName.valueOf(table),
            TableName.valueOf(tableMap[i++]));
        }
      }
    }
  }

  /**
   * @param conf The {@link Configuration} to use.
   */
  public WALPlayer(Configuration conf) {
    super(conf);
  }

  void setupTime(Configuration conf, String option) throws IOException {
    String val = conf.get(option);
    if (null == val) return;
    long ms;
    try {
      // first try to parse in user friendly form
      ms = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SS").parse(val).getTime();
    } catch (ParseException pe) {
      try {
        // then see if just a number of ms's was specified
        ms = Long.parseLong(val);
      } catch (NumberFormatException nfe) {
        throw new IOException(option
            + " must be specified either in the form 2001-02-20T16:35:06.99 "
            + "or as number of milliseconds");
      }
    }
    conf.setLong(option, ms);
  }

  /**
   * Sets up the actual job.
   *
   * @param args  The command line parameters.
   * @return The newly created job.
   * @throws IOException When setting up the job fails.
   */
  public Job createSubmittableJob(String[] args)
  throws IOException {
    Configuration conf = getConf();
    setupTime(conf, HLogInputFormat.START_TIME_KEY);
    setupTime(conf, HLogInputFormat.END_TIME_KEY);
    Path inputDir = new Path(args[0]);
    String[] tables = args[1].split(",");
    String[] tableMap;
    if (args.length > 2) {
      tableMap = args[2].split(",");
      if (tableMap.length != tables.length) {
        throw new IOException("The same number of tables and mapping must be provided.");
      }
    } else {
      // if not mapping is specified map each table to itself
      tableMap = tables;
    }
    conf.setStrings(TABLES_KEY, tables);
    conf.setStrings(TABLE_MAP_KEY, tableMap);
    Job job = new Job(conf, NAME + "_" + inputDir);
    job.setJarByClass(WALPlayer.class);
    FileInputFormat.setInputPaths(job, inputDir);
    job.setInputFormatClass(WALInputFormat.class);
    job.setMapOutputKeyClass(ImmutableBytesWritable.class);
    String hfileOutPath = conf.get(BULK_OUTPUT_CONF_KEY);
    if (hfileOutPath != null) {
      // the bulk HFile case
      if (tables.length != 1) {
        throw new IOException("Exactly one table must be specified for the bulk export option");
      }
      TableName tableName = TableName.valueOf(tables[0]);
      job.setMapperClass(WALKeyValueMapper.class);
      job.setReducerClass(KeyValueSortReducer.class);
      Path outputDir = new Path(hfileOutPath);
      FileOutputFormat.setOutputPath(job, outputDir);
      job.setMapOutputValueClass(KeyValue.class);
      try (Connection conn = ConnectionFactory.createConnection(conf);
          Table table = conn.getTable(tableName);
          RegionLocator regionLocator = conn.getRegionLocator(tableName)) {
        HFileOutputFormat2.configureIncrementalLoad(job, table.getTableDescriptor(), regionLocator);
      }
      TableMapReduceUtil.addDependencyJarsForClasses(job.getConfiguration(),
          com.google.common.base.Preconditions.class);
    } else {
      // output to live cluster
      job.setMapperClass(WALMapper.class);
      job.setOutputFormatClass(MultiTableOutputFormat.class);
      TableMapReduceUtil.addDependencyJars(job);
      TableMapReduceUtil.initCredentials(job);
      // No reducers.
      job.setNumReduceTasks(0);
    }
    String codecCls = WALCellCodec.getWALCellCodecClass(conf);
    try {
      TableMapReduceUtil.addDependencyJarsForClasses(job.getConfiguration(), Class.forName(codecCls));
    } catch (Exception e) {
      throw new IOException("Cannot determine wal codec class " + codecCls, e);
    }
    return job;
  }

  /*
   * @param errorMsg Error message.  Can be null.
   */
  private void usage(final String errorMsg) {
    if (errorMsg != null && errorMsg.length() > 0) {
      System.err.println("ERROR: " + errorMsg);
    }
    System.err.println("Usage: " + NAME + " [options]   []");
    System.err.println("Read all WAL entries for .");
    System.err.println("If no tables (\"\") are specific, all tables are imported.");
    System.err.println("(Careful, even -ROOT- and hbase:meta entries will be imported in that case.)");
    System.err.println("Otherwise  is a comma separated list of tables.\n");
    System.err.println("The WAL entries can be mapped to new set of tables via .");
    System.err.println(" is a command separated list of targettables.");
    System.err.println("If specified, each table in  must have a mapping.\n");
    System.err.println("By default " + NAME + " will load data directly into HBase.");
    System.err.println("To generate HFiles for a bulk data load instead, pass the option:");
    System.err.println("  -D" + BULK_OUTPUT_CONF_KEY + "=/path/for/output");
    System.err.println("  (Only one table can be specified, and no mapping is allowed!)");
    System.err.println("Other options: (specify time range to WAL edit to consider)");
    System.err.println("  -D" + WALInputFormat.START_TIME_KEY + "=[date|ms]");
    System.err.println("  -D" + WALInputFormat.END_TIME_KEY + "=[date|ms]");
    System.err.println("For performance also consider the following options:\n"
        + "  -Dmapreduce.map.speculative=false\n"
        + "  -Dmapreduce.reduce.speculative=false");
  }

  /**
   * Main entry point.
   *
   * @param args  The command line parameters.
   * @throws Exception When running the job fails.
   */
  public static void main(String[] args) throws Exception {
    int ret = ToolRunner.run(new WALPlayer(HBaseConfiguration.create()), args);
    System.exit(ret);
  }

  @Override
  public int run(String[] args) throws Exception {
    String[] otherArgs = new GenericOptionsParser(getConf(), args).getRemainingArgs();
    if (otherArgs.length < 2) {
      usage("Wrong number of arguments: " + otherArgs.length);
      System.exit(-1);
    }
    Job job = createSubmittableJob(otherArgs);
    return job.waitForCompletion(true) ? 0 : 1;
  }
}




© 2015 - 2024 Weber Informatics LLC | Privacy Policy