/**
*
* 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 java.io.IOException;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.client.Result;
import org.apache.hadoop.hbase.client.Scan;
import org.apache.hadoop.hbase.filter.PrefixFilter;
import org.apache.hadoop.hbase.filter.RowFilter;
import org.apache.hadoop.hbase.filter.RegexStringComparator;
import org.apache.hadoop.hbase.filter.CompareFilter.CompareOp;
import org.apache.hadoop.hbase.filter.Filter;
import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
import org.apache.hadoop.hbase.util.Bytes;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.mapreduce.lib.output.SequenceFileOutputFormat;
import org.apache.hadoop.util.GenericOptionsParser;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
/**
* Export an HBase table.
* Writes content to sequence files up in HDFS. Use {@link Import} to read it
* back in again.
*/
@InterfaceAudience.Public
@InterfaceStability.Stable
public class Export {
private static final Log LOG = LogFactory.getLog(Export.class);
final static String NAME = "export";
final static String RAW_SCAN = "hbase.mapreduce.include.deleted.rows";
final static String EXPORT_BATCHING = "hbase.export.scanner.batch";
/**
* Mapper.
*/
static class Exporter
extends TableMapper<ImmutableBytesWritable, Result> {
/**
* @param row The current table row key.
* @param value The columns.
* @param context The current context.
* @throws IOException When something is broken with the data.
* @see org.apache.hadoop.mapreduce.Mapper#map(KEYIN, VALUEIN,
* org.apache.hadoop.mapreduce.Mapper.Context)
*/
@Override
public void map(ImmutableBytesWritable row, Result value,
Context context)
throws IOException {
try {
context.write(row, value);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
/**
* Sets up the actual job.
*
* @param conf The current configuration.
* @param args The command line parameters.
* @return The newly created job.
* @throws IOException When setting up the job fails.
*/
public static Job createSubmittableJob(Configuration conf, String[] args)
throws IOException {
String tableName = args[0];
Path outputDir = new Path(args[1]);
Job job = new Job(conf, NAME + "_" + tableName);
job.setJobName(NAME + "_" + tableName);
job.setJarByClass(Exporter.class);
// Set optional scan parameters
Scan s = getConfiguredScanForJob(conf, args);
TableMapReduceUtil.initTableMapperJob(tableName, s, Exporter.class, null,
null, job);
// No reducers. Just write straight to output files.
job.setNumReduceTasks(0);
job.setOutputFormatClass(SequenceFileOutputFormat.class);
job.setOutputKeyClass(ImmutableBytesWritable.class);
job.setOutputValueClass(Result.class);
FileOutputFormat.setOutputPath(job, outputDir);
return job;
}
private static Scan getConfiguredScanForJob(Configuration conf, String[] args) throws IOException {
Scan s = new Scan();
// Optional arguments.
// Set Scan Versions
int versions = args.length > 2? Integer.parseInt(args[2]): 1;
s.setMaxVersions(versions);
// Set Scan Range
long startTime = args.length > 3? Long.parseLong(args[3]): 0L;
long endTime = args.length > 4? Long.parseLong(args[4]): Long.MAX_VALUE;
s.setTimeRange(startTime, endTime);
// Set cache blocks
s.setCacheBlocks(false);
// Set Scan Column Family
boolean raw = Boolean.parseBoolean(conf.get(RAW_SCAN));
if (raw) {
s.setRaw(raw);
}
if (conf.get(TableInputFormat.SCAN_COLUMN_FAMILY) != null) {
s.addFamily(Bytes.toBytes(conf.get(TableInputFormat.SCAN_COLUMN_FAMILY)));
}
// Set RowFilter or Prefix Filter if applicable.
Filter exportFilter = getExportFilter(args);
if (exportFilter!= null) {
LOG.info("Setting Scan Filter for Export.");
s.setFilter(exportFilter);
}
int batching = conf.getInt(EXPORT_BATCHING, -1);
if (batching != -1){
try{
s.setBatch(batching);
} catch (RuntimeException e) {
LOG.error("Batching could not be set", e);
}
}
LOG.info("versions=" + versions + ", starttime=" + startTime +
", endtime=" + endTime + ", keepDeletedCells=" + raw);
return s;
}
private static Filter getExportFilter(String[] args) {
Filter exportFilter = null;
String filterCriteria = (args.length > 5) ? args[5]: null;
if (filterCriteria == null) return null;
if (filterCriteria.startsWith("^")) {
String regexPattern = filterCriteria.substring(1, filterCriteria.length());
exportFilter = new RowFilter(CompareOp.EQUAL, new RegexStringComparator(regexPattern));
} else {
exportFilter = new PrefixFilter(Bytes.toBytes(filterCriteria));
}
return exportFilter;
}
/*
* @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: Export [-D <property=value>]* <tablename> <outputdir> [<versions> " +
"[<starttime> [<endtime>]] [^[regex pattern] or [Prefix] to filter]]\n");
System.err.println(" Note: -D properties will be applied to the conf used. ");
System.err.println(" For example: ");
System.err.println(" -D mapred.output.compress=true");
System.err.println(" -D mapred.output.compression.codec=org.apache.hadoop.io.compress.GzipCodec");
System.err.println(" -D mapred.output.compression.type=BLOCK");
System.err.println(" Additionally, the following SCAN properties can be specified");
System.err.println(" to control/limit what is exported..");
System.err.println(" -D " + TableInputFormat.SCAN_COLUMN_FAMILY + "=<familyName>");
System.err.println(" -D " + RAW_SCAN + "=true");
System.err.println("For performance consider the following properties:\n"
+ " -Dhbase.client.scanner.caching=100\n"
+ " -Dmapred.map.tasks.speculative.execution=false\n"
+ " -Dmapred.reduce.tasks.speculative.execution=false");
System.err.println("For tables with very wide rows consider setting the batch size as below:\n"
+ " -D" + EXPORT_BATCHING + "=10");
}
/**
* 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);
}
}