/*
* 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.
*/
/**
* Cassandra has a back door called the Binary Memtable. The purpose of this backdoor is to
* mass import large amounts of data, without using the Thrift interface.
*
* Inserting data through the binary memtable, allows you to skip the commit log overhead, and an ack
* from Thrift on every insert. The example below utilizes Hadoop to generate all the data necessary
* to send to Cassandra, and sends it using the Binary Memtable interface. What Hadoop ends up doing is
* creating the actual data that gets put into an SSTable as if you were using Thrift. With enough Hadoop nodes
* inserting the data, the bottleneck at this point should become the network.
*
* We recommend adjusting the compaction threshold to 0, while the import is running. After the import, you need
* to run `nodeprobe -host <IP> flush_binary <Keyspace>` on every node, as this will flush the remaining data still left
* in memory to disk. Then it's recommended to adjust the compaction threshold to it's original value.
*
* The example below is a sample Hadoop job, and it inserts SuperColumns. It can be tweaked to work with normal Columns.
*
* You should construct your data you want to import as rows delimited by a new line. You end up grouping by <Key>
* in the mapper, so that the end result generates the data set into a column oriented subset. Once you get to the
* reduce aspect, you can generate the ColumnFamilies you want inserted, and send it to your nodes.
*
* For Cassandra 0.6.4, we modified this example to wait for acks from all Cassandra nodes for each row
* before proceeding to the next. This means to keep Cassandra similarly busy you can either
* 1) add more reducer tasks,
* 2) remove the "wait for acks" block of code,
* 3) parallelize the writing of rows to Cassandra, e.g. with an Executor.
*
* THIS CANNOT RUN ON THE SAME IP ADDRESS AS A CASSANDRA INSTANCE.
*/
package org.apache.cassandra.bulkloader;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.math.BigInteger;
import java.net.URI;
import java.net.URISyntaxException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import org.apache.cassandra.config.CFMetaData;
import org.apache.cassandra.config.DatabaseDescriptor;
import org.apache.cassandra.db.clock.TimestampReconciler;
import org.apache.cassandra.db.*;
import org.apache.cassandra.db.filter.QueryPath;
import org.apache.cassandra.dht.BigIntegerToken;
import org.apache.cassandra.io.util.DataOutputBuffer;
import java.net.InetAddress;
import java.net.UnknownHostException;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import org.apache.cassandra.net.IAsyncResult;
import org.apache.cassandra.net.Message;
import org.apache.cassandra.net.MessagingService;
import org.apache.cassandra.service.StorageService;
import org.apache.cassandra.utils.FBUtilities;
import org.apache.hadoop.filecache.DistributedCache;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapred.*;
public class CassandraBulkLoader {
public static class Map extends MapReduceBase implements Mapper<Text, Text, Text, Text> {
private Text word = new Text();
public void map(Text key, Text value, OutputCollector<Text, Text> output, Reporter reporter) throws IOException {
// This is a simple key/value mapper.
output.collect(key, value);
}
}
public static class Reduce extends MapReduceBase implements Reducer<Text, Text, Text, Text> {
private Path[] localFiles;
private ArrayList<String> tokens = new ArrayList<String>();
private JobConf jobconf;
public void configure(JobConf job) {
this.jobconf = job;
String cassConfig;
// Get the cached files
try
{
localFiles = DistributedCache.getLocalCacheFiles(job);
}
catch (IOException e)
{
throw new RuntimeException(e);
}
cassConfig = localFiles[0].getParent().toString();
System.setProperty("storage-config",cassConfig);
try
{
StorageService.instance.initClient();
}
catch (IOException e)
{
throw new RuntimeException(e);
}
try
{
Thread.sleep(10*1000);
}
catch (InterruptedException e)
{
throw new RuntimeException(e);
}
}
public void close()
{
try
{
// release the cache
DistributedCache.releaseCache(new URI("/cassandra/storage-conf.xml#storage-conf.xml"), this.jobconf);
}
catch (IOException e)
{
throw new RuntimeException(e);
}
catch (URISyntaxException e)
{
throw new RuntimeException(e);
}
try
{
// Sleep just in case the number of keys we send over is small
Thread.sleep(3*1000);
}
catch (InterruptedException e)
{
throw new RuntimeException(e);
}
StorageService.instance.stopClient();
}
public void reduce(Text key, Iterator<Text> values, OutputCollector<Text, Text> output, Reporter reporter) throws IOException
{
ColumnFamily columnFamily;
String keyspace = "Keyspace1";
String cfName = "Super1";
Message message;
List<ColumnFamily> columnFamilies;
columnFamilies = new LinkedList<ColumnFamily>();
String line;
/* Create a column family */
columnFamily = ColumnFamily.create(keyspace, cfName);
while (values.hasNext()) {
// Split the value (line based on your own delimiter)
line = values.next().toString();
String[] fields = line.split("\1");
String SuperColumnName = fields[1];
String ColumnName = fields[2];
String ColumnValue = fields[3];
int timestamp = 0;
columnFamily.addColumn(new QueryPath(cfName, SuperColumnName.getBytes("UTF-8"), ColumnName.getBytes("UTF-8")), ColumnValue.getBytes(), new TimestampClock(timestamp));
}
columnFamilies.add(columnFamily);
/* Get serialized message to send to cluster */
message = createMessage(keyspace, key.getBytes(), cfName, columnFamilies);
List<IAsyncResult> results = new ArrayList<IAsyncResult>();
for (InetAddress endpoint: StorageService.instance.getNaturalEndpoints(keyspace, key.getBytes()))
{
/* Send message to end point */
results.add(MessagingService.instance.sendRR(message, endpoint));
}
/* wait for acks */
for (IAsyncResult result : results)
{
try
{
result.get(DatabaseDescriptor.getRpcTimeout(), TimeUnit.MILLISECONDS);
}
catch (TimeoutException e)
{
// you should probably add retry logic here
throw new RuntimeException(e);
}
}
output.collect(key, new Text(" inserted into Cassandra node(s)"));
}
}
public static void runJob(String[] args)
{
JobConf conf = new JobConf(CassandraBulkLoader.class);
if(args.length >= 4)
{
conf.setNumReduceTasks(new Integer(args[3]));
}
try
{
// We store the cassandra storage-conf.xml on the HDFS cluster
DistributedCache.addCacheFile(new URI("/cassandra/storage-conf.xml#storage-conf.xml"), conf);
}
catch (URISyntaxException e)
{
throw new RuntimeException(e);
}
conf.setInputFormat(KeyValueTextInputFormat.class);
conf.setJobName("CassandraBulkLoader_v2");
conf.setMapperClass(Map.class);
conf.setReducerClass(Reduce.class);
conf.setOutputKeyClass(Text.class);
conf.setOutputValueClass(Text.class);
FileInputFormat.setInputPaths(conf, new Path(args[1]));
FileOutputFormat.setOutputPath(conf, new Path(args[2]));
try
{
JobClient.runJob(conf);
}
catch (IOException e)
{
throw new RuntimeException(e);
}
}
public static Message createMessage(String Keyspace, byte[] Key, String CFName, List<ColumnFamily> ColumnFamiles)
{
ColumnFamily baseColumnFamily;
DataOutputBuffer bufOut = new DataOutputBuffer();
RowMutation rm;
Message message;
Column column;
/* Get the first column family from list, this is just to get past validation */
baseColumnFamily = new ColumnFamily(ColumnFamilyType.Standard,
ClockType.Timestamp,
DatabaseDescriptor.getComparator(Keyspace, CFName),
DatabaseDescriptor.getSubComparator(Keyspace, CFName),
new TimestampReconciler(),
CFMetaData.getId(Keyspace, CFName));
for(ColumnFamily cf : ColumnFamiles) {
bufOut.reset();
ColumnFamily.serializer().serializeWithIndexes(cf, bufOut);
byte[] data = new byte[bufOut.getLength()];
System.arraycopy(bufOut.getData(), 0, data, 0, bufOut.getLength());
column = new Column(FBUtilities.toByteArray(cf.id()), data, new TimestampClock(0));
baseColumnFamily.addColumn(column);
}
rm = new RowMutation(Keyspace, Key);
rm.add(baseColumnFamily);
try
{
/* Make message */
message = rm.makeRowMutationMessage(StorageService.Verb.BINARY);
}
catch (IOException e)
{
throw new RuntimeException(e);
}
return message;
}
public static void main(String[] args) throws Exception
{
runJob(args);
}
}