org.apache.hadoop.hbase.mapreduce.replication.VerifyReplication Maven / Gradle / Ivy
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/**
* Copyright 2010 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.replication;
import java.io.IOException;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.HConstants;
import org.apache.hadoop.hbase.KeyValue;
import org.apache.hadoop.hbase.client.HConnection;
import org.apache.hadoop.hbase.client.HConnectionManager;
import org.apache.hadoop.hbase.client.HConnectionManager.HConnectable;
import org.apache.hadoop.hbase.client.HTable;
import org.apache.hadoop.hbase.client.Put;
import org.apache.hadoop.hbase.client.Result;
import org.apache.hadoop.hbase.client.ResultScanner;
import org.apache.hadoop.hbase.client.Scan;
import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
import org.apache.hadoop.hbase.mapreduce.TableInputFormat;
import org.apache.hadoop.hbase.mapreduce.TableMapReduceUtil;
import org.apache.hadoop.hbase.mapreduce.TableMapper;
import org.apache.hadoop.hbase.replication.ReplicationPeer;
import org.apache.hadoop.hbase.replication.ReplicationZookeeper;
import org.apache.hadoop.hbase.util.Bytes;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.lib.output.NullOutputFormat;
import org.apache.zookeeper.KeeperException;
/**
* This map-only job compares the data from a local table with a remote one.
* Every cell is compared and must have exactly the same keys (even timestamp)
* as well as same value. It is possible to restrict the job by time range and
* families. The peer id that's provided must match the one given when the
* replication stream was setup.
*
* Two counters are provided, Verifier.Counters.GOODROWS and BADROWS. The reason
* for a why a row is different is shown in the map's log.
*/
public class VerifyReplication {
private static final Log LOG =
LogFactory.getLog(VerifyReplication.class);
public final static String NAME = "verifyrep";
static long startTime = 0;
static long endTime = 0;
static String tableName = null;
static String families = null;
static String peerId = null;
/**
* Map-only comparator for 2 tables
*/
public static class Verifier
extends TableMapper {
public static enum Counters {GOODROWS, BADROWS}
private ResultScanner replicatedScanner;
/**
* Map method that compares every scanned row with the equivalent from
* a distant cluster.
* @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.
*/
@Override
public void map(ImmutableBytesWritable row, final Result value,
Context context)
throws IOException {
if (replicatedScanner == null) {
Configuration conf = context.getConfiguration();
final Scan scan = new Scan();
scan.setCaching(conf.getInt(TableInputFormat.SCAN_CACHEDROWS, 1));
long startTime = conf.getLong(NAME + ".startTime", 0);
long endTime = conf.getLong(NAME + ".endTime", 0);
String families = conf.get(NAME + ".families", null);
if(families != null) {
String[] fams = families.split(",");
for(String fam : fams) {
scan.addFamily(Bytes.toBytes(fam));
}
}
if (startTime != 0) {
scan.setTimeRange(startTime,
endTime == 0 ? HConstants.LATEST_TIMESTAMP : endTime);
}
HConnectionManager.execute(new HConnectable(conf) {
@Override
public Void connect(HConnection conn) throws IOException {
try {
ReplicationZookeeper zk = new ReplicationZookeeper(conn, conf,
conn.getZooKeeperWatcher());
ReplicationPeer peer = zk.getPeer(conf.get(NAME+".peerId"));
HTable replicatedTable = new HTable(peer.getConfiguration(),
conf.get(NAME+".tableName"));
scan.setStartRow(value.getRow());
replicatedScanner = replicatedTable.getScanner(scan);
} catch (KeeperException e) {
throw new IOException("Got a ZK exception", e);
}
return null;
}
});
}
Result res = replicatedScanner.next();
try {
Result.compareResults(value, res);
context.getCounter(Counters.GOODROWS).increment(1);
} catch (Exception e) {
LOG.warn("Bad row", e);
context.getCounter(Counters.BADROWS).increment(1);
}
}
protected void cleanup(Context context) {
if (replicatedScanner != null) {
replicatedScanner.close();
replicatedScanner = null;
}
}
}
/**
* 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 {
if (!doCommandLine(args)) {
return null;
}
if (!conf.getBoolean(HConstants.REPLICATION_ENABLE_KEY, false)) {
throw new IOException("Replication needs to be enabled to verify it.");
}
HConnectionManager.execute(new HConnectable(conf) {
@Override
public Void connect(HConnection conn) throws IOException {
try {
ReplicationZookeeper zk = new ReplicationZookeeper(conn, conf,
conn.getZooKeeperWatcher());
// Just verifying it we can connect
ReplicationPeer peer = zk.getPeer(peerId);
if (peer == null) {
throw new IOException("Couldn't get access to the slave cluster," +
"please see the log");
}
} catch (KeeperException ex) {
throw new IOException("Couldn't get access to the slave cluster" +
" because: ", ex);
}
return null;
}
});
conf.set(NAME+".peerId", peerId);
conf.set(NAME+".tableName", tableName);
conf.setLong(NAME+".startTime", startTime);
conf.setLong(NAME+".endTime", endTime);
if (families != null) {
conf.set(NAME+".families", families);
}
Job job = new Job(conf, NAME + "_" + tableName);
job.setJarByClass(VerifyReplication.class);
Scan scan = new Scan();
if (startTime != 0) {
scan.setTimeRange(startTime,
endTime == 0 ? HConstants.LATEST_TIMESTAMP : endTime);
}
if(families != null) {
String[] fams = families.split(",");
for(String fam : fams) {
scan.addFamily(Bytes.toBytes(fam));
}
}
TableMapReduceUtil.initTableMapperJob(tableName, scan,
Verifier.class, null, null, job);
job.setOutputFormatClass(NullOutputFormat.class);
job.setNumReduceTasks(0);
return job;
}
private static boolean doCommandLine(final String[] args) {
if (args.length < 2) {
printUsage(null);
return false;
}
try {
for (int i = 0; i < args.length; i++) {
String cmd = args[i];
if (cmd.equals("-h") || cmd.startsWith("--h")) {
printUsage(null);
return false;
}
final String startTimeArgKey = "--starttime=";
if (cmd.startsWith(startTimeArgKey)) {
startTime = Long.parseLong(cmd.substring(startTimeArgKey.length()));
continue;
}
final String endTimeArgKey = "--endtime=";
if (cmd.startsWith(endTimeArgKey)) {
endTime = Long.parseLong(cmd.substring(endTimeArgKey.length()));
continue;
}
final String familiesArgKey = "--families=";
if (cmd.startsWith(familiesArgKey)) {
families = cmd.substring(familiesArgKey.length());
continue;
}
if (i == args.length-2) {
peerId = cmd;
}
if (i == args.length-1) {
tableName = cmd;
}
}
} catch (Exception e) {
e.printStackTrace();
printUsage("Can't start because " + e.getMessage());
return false;
}
return true;
}
/*
* @param errorMsg Error message. Can be null.
*/
private static void printUsage(final String errorMsg) {
if (errorMsg != null && errorMsg.length() > 0) {
System.err.println("ERROR: " + errorMsg);
}
System.err.println("Usage: verifyrep [--starttime=X]" +
" [--stoptime=Y] [--families=A] ");
System.err.println();
System.err.println("Options:");
System.err.println(" starttime beginning of the time range");
System.err.println(" without endtime means from starttime to forever");
System.err.println(" stoptime end of the time range");
System.err.println(" families comma-separated list of families to copy");
System.err.println();
System.err.println("Args:");
System.err.println(" peerid Id of the peer used for verification, must match the one given for replication");
System.err.println(" tablename Name of the table to verify");
System.err.println();
System.err.println("Examples:");
System.err.println(" To verify the data replicated from TestTable for a 1 hour window with peer #5 ");
System.err.println(" $ bin/hbase " +
"org.apache.hadoop.hbase.mapreduce.replication.VerifyReplication" +
" --starttime=1265875194289 --stoptime=1265878794289 5 TestTable ");
}
/**
* 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();
Job job = createSubmittableJob(conf, args);
if (job != null) {
System.exit(job.waitForCompletion(true) ? 0 : 1);
}
}
}