Hacked HBase 0.92.1 Import MR to selectively import rows into HBase

HBaseSelectiveImport.java

/**
 * Copyright 2009 The Apache Software Foundation
 *
 * 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.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.KeyValue;
import org.apache.hadoop.hbase.client.Put;
import org.apache.hadoop.hbase.client.Result;
import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
import org.apache.hadoop.hbase.mapreduce.TableMapReduceUtil;
import org.apache.hadoop.hbase.mapreduce.TableMapper;
import org.apache.hadoop.hbase.util.Bytes;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.input.SequenceFileInputFormat;
import org.apache.hadoop.util.GenericOptionsParser;

import java.io.IOException;
import java.util.Map;
import java.util.TreeMap;

/**
 * Import data written by {@link org.apache.hadoop.hbase.mapreduce.Export}.
 */
public class HBaseSelectiveImport {
    final static String NAME = "import";
    public static final String CF_RENAME_PROP = "HBASE_IMPORTER_RENAME_CFS";
    public static final String KEYRANGE_CONFIG = "import.keysubset";

    /**
     * Write table content out to files in hdfs.
     */
    static class Importer
            extends TableMapper<ImmutableBytesWritable, Put> {
        private Map<byte[], byte[]> cfRenameMap;
        private byte[] keySubsetConfig;

        /**
         * @param row     The current table row key.
         * @param value   The columns.
         * @param context The current context.
         * @throws java.io.IOException When something is broken with the data.
         */
        @Override
        public void map(ImmutableBytesWritable row, Result value,
                        Context context)
                throws IOException {
            if (Bytes.startsWith(row.get(), keySubsetConfig)) {
                try {
                    context.write(row, resultToPut(row, value));
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }

        private Put resultToPut(ImmutableBytesWritable key, Result result)
                throws IOException {
            Put put = new Put(key.get());
            for (KeyValue kv : result.raw()) {
                if (cfRenameMap != null) {
                    // If there's a rename mapping for this CF, create a new KeyValue
                    byte[] newCfName = cfRenameMap.get(kv.getFamily());
                    if (newCfName != null) {
                        kv = new KeyValue(kv.getBuffer(), // row buffer
                                kv.getRowOffset(),        // row offset
                                kv.getRowLength(),        // row length
                                newCfName,                // CF buffer
                                0,                        // CF offset
                                newCfName.length,         // CF length
                                kv.getBuffer(),           // qualifier buffer
                                kv.getQualifierOffset(),  // qualifier offset
                                kv.getQualifierLength(),  // qualifier length
                                kv.getTimestamp(),        // timestamp
                                KeyValue.Type.codeToType(kv.getType()), // KV Type
                                kv.getBuffer(),           // value buffer
                                kv.getValueOffset(),      // value offset
                                kv.getValueLength());     // value length
                    }
                }
                put.add(kv);
            }
            return put;
        }

        @Override
        public void setup(Context context) {
            // Make a map from sourceCfName to destCfName by parsing a config key
            cfRenameMap = null;
            String allMappingsPropVal = context.getConfiguration().get(CF_RENAME_PROP);
            if (allMappingsPropVal != null) {
                // The conf value format should be sourceCf1:destCf1,sourceCf2:destCf2,...
                String[] allMappings = allMappingsPropVal.split(",");
                for (String mapping : allMappings) {
                    if (cfRenameMap == null) {
                        cfRenameMap = new TreeMap<byte[], byte[]>(Bytes.BYTES_COMPARATOR);
                    }
                    String[] srcAndDest = mapping.split(":");
                    if (srcAndDest.length != 2) {
                        continue;
                    }
                    cfRenameMap.put(srcAndDest[0].getBytes(), srcAndDest[1].getBytes());
                }
            }

            String keySubstringConfig = context.getConfiguration().get(KEYRANGE_CONFIG, "");
            keySubsetConfig = Bytes.toBytes(keySubstringConfig);
        }
    }

    /**
     * <p>Sets a configuration property with key {@link #CF_RENAME_PROP} in conf that tells
     * the mapper how to rename column families.
     * <p/>
     * <p>Alternately, instead of calling this function, you could set the configuration key
     * {@link #CF_RENAME_PROP} yourself. The value should look like
     * <pre>srcCf1:destCf1,srcCf2:destCf2,....</pre>. This would have the same effect on
     * the mapper behavior.
     *
     * @param conf      the Configuration in which the {@link #CF_RENAME_PROP} key will be
     *                  set
     * @param renameMap a mapping from source CF names to destination CF names
     */
    static public void configureCfRenaming(Configuration conf,
                                           Map<String, String> renameMap) {
        StringBuilder sb = new StringBuilder();
        for (Map.Entry<String, String> entry : renameMap.entrySet()) {
            String sourceCf = entry.getKey();
            String destCf = entry.getValue();

            if (sourceCf.contains(":") || sourceCf.contains(",") ||
                    destCf.contains(":") || destCf.contains(",")) {
                throw new IllegalArgumentException("Illegal character in CF names: "
                        + sourceCf + ", " + destCf);
            }

            if (sb.length() != 0) {
                sb.append(",");
            }
            sb.append(sourceCf + ":" + destCf);
        }
        conf.set(CF_RENAME_PROP, sb.toString());
    }


    /**
     * Sets up the actual job.
     *
     * @param conf The current configuration.
     * @param args The command line parameters.
     * @return The newly created job.
     * @throws java.io.IOException When setting up the job fails.
     */
    public static Job createSubmittableJob(Configuration conf, String[] args)
            throws IOException {
        String tableName = args[0];
        Path inputDir = new Path(args[1]);
        Job job = new Job(conf, NAME + "_" + tableName);
        job.setJarByClass(Importer.class);
        FileInputFormat.setInputPaths(job, inputDir);
        job.setInputFormatClass(SequenceFileInputFormat.class);
        job.setMapperClass(Importer.class);
        // No reducers.  Just write straight to table.  Call initTableReducerJob
        // because it sets up the TableOutputFormat.
        TableMapReduceUtil.initTableReducerJob(tableName, null, job);
        job.setNumReduceTasks(0);
        return job;
    }

    /*
    * @param errorMsg Error message.  Can be null.
    */
    private static void usage(final String errorMsg) {
        if (errorMsg != null && errorMsg.length() > 0) {
            System.err.println("ERROR: " + errorMsg);
        }
        System.err.println("Usage: Import <tablename> <inputdir>");
    }

    /**
     * Main entry point.
     *
     * @param args The command line parameters.
     * @throws Exception When running the job fails.
     */
    public static void main(String[] args) throws Exception {
        Configuration conf = HBaseConfiguration.create();
        String[] otherArgs = new GenericOptionsParser(conf, args).getRemainingArgs();
        if (otherArgs.length < 2) {
            usage("Wrong number of arguments: " + otherArgs.length);
            System.exit(-1);
        }
        Job job = createSubmittableJob(conf, otherArgs);
        System.exit(job.waitForCompletion(true) ? 0 : 1);
    }
}