Java tutorial
package mvm.rya.accumulo.mr.utils; /* * 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. */ import java.io.IOException; import java.util.ArrayList; import java.util.Collections; import java.util.HashSet; import java.util.List; import java.util.Map; import org.apache.accumulo.core.Constants; import org.apache.accumulo.core.client.Connector; import org.apache.accumulo.core.client.Instance; import org.apache.accumulo.core.client.Scanner; import org.apache.accumulo.core.client.admin.TableOperations; import org.apache.accumulo.core.client.mapreduce.AccumuloInputFormat; import org.apache.accumulo.core.client.security.tokens.AuthenticationToken; import org.apache.accumulo.core.client.security.tokens.PasswordToken; import org.apache.accumulo.core.conf.AccumuloConfiguration; import org.apache.accumulo.core.conf.Property; import org.apache.accumulo.core.data.ByteSequence; import org.apache.accumulo.core.data.Key; import org.apache.accumulo.core.data.Range; import org.apache.accumulo.core.data.Value; import org.apache.accumulo.core.file.FileSKVIterator; import org.apache.accumulo.core.file.rfile.RFileOperations; import org.apache.accumulo.core.util.ArgumentChecker; import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.fs.BlockLocation; import org.apache.hadoop.fs.FileStatus; import org.apache.hadoop.fs.FileSystem; import org.apache.hadoop.fs.Path; import org.apache.hadoop.io.Text; import org.apache.hadoop.mapreduce.InputSplit; import org.apache.hadoop.mapreduce.Job; import org.apache.hadoop.mapreduce.JobContext; import org.apache.hadoop.mapreduce.Mapper; import org.apache.hadoop.mapreduce.RecordReader; import org.apache.hadoop.mapreduce.TaskAttemptContext; import org.apache.hadoop.mapreduce.lib.input.FileInputFormat; import org.apache.hadoop.mapreduce.lib.input.FileSplit; import org.apache.hadoop.mapreduce.lib.output.NullOutputFormat; /** * Finds the accumulo tablet files on the hdfs disk, and uses that as the input for MR jobs * Date: 5/11/12 * Time: 2:04 PM */ public class AccumuloHDFSFileInputFormat extends FileInputFormat<Key, Value> { public static final Range ALLRANGE = new Range(new Text("\u0000"), new Text("\uFFFD")); @Override public List<InputSplit> getSplits(JobContext jobContext) throws IOException { //read the params from AccumuloInputFormat Configuration conf = jobContext.getConfiguration(); Instance instance = AccumuloProps.getInstance(jobContext); String user = AccumuloProps.getUsername(jobContext); AuthenticationToken password = AccumuloProps.getPassword(jobContext); String table = AccumuloProps.getTablename(jobContext); ArgumentChecker.notNull(instance); ArgumentChecker.notNull(table); //find the files necessary try { AccumuloConfiguration acconf = instance.getConfiguration(); FileSystem fs = FileSystem.get(conf); Connector connector = instance.getConnector(user, password); TableOperations tos = connector.tableOperations(); String tableId = tos.tableIdMap().get(table); String filePrefix = acconf.get(Property.INSTANCE_DFS_DIR) + "/tables/" + tableId; System.out.println(filePrefix); Scanner scanner = connector.createScanner("!METADATA", Constants.NO_AUTHS); //TODO: auths? scanner.setRange(new Range(new Text(tableId + "\u0000"), new Text(tableId + "\uFFFD"))); scanner.fetchColumnFamily(new Text("file")); List<String> files = new ArrayList<String>(); List<InputSplit> fileSplits = new ArrayList<InputSplit>(); Job job = new Job(conf); for (Map.Entry<Key, Value> entry : scanner) { String file = filePrefix + entry.getKey().getColumnQualifier().toString(); files.add(file); Path path = new Path(file); FileStatus fileStatus = fs.getFileStatus(path); long len = fileStatus.getLen(); BlockLocation[] fileBlockLocations = fs.getFileBlockLocations(fileStatus, 0, len); fileSplits.add(new FileSplit(path, 0, len, fileBlockLocations[0].getHosts())); // FileInputFormat.addInputPath(job, path); } System.out.println(files); return fileSplits; // return super.getSplits(job); } catch (Exception e) { throw new IOException(e); } } @Override public RecordReader<Key, Value> createRecordReader(InputSplit inputSplit, TaskAttemptContext taskAttemptContext) throws IOException, InterruptedException { return new RecordReader<Key, Value>() { private FileSKVIterator fileSKVIterator; @Override public void initialize(InputSplit inputSplit, TaskAttemptContext taskAttemptContext) throws IOException, InterruptedException { FileSplit split = (FileSplit) inputSplit; Configuration job = taskAttemptContext.getConfiguration(); Path file = split.getPath(); // long start = split.getStart(); // long length = split.getLength(); FileSystem fs = file.getFileSystem(job); // FSDataInputStream fileIn = fs.open(file); // System.out.println(start); // if (start != 0L) { // fileIn.seek(start); // } Instance instance = AccumuloProps.getInstance(taskAttemptContext); fileSKVIterator = RFileOperations.getInstance().openReader(file.toString(), ALLRANGE, new HashSet<ByteSequence>(), false, fs, job, instance.getConfiguration()); // fileSKVIterator = new RFileOperations2().openReader(fileIn, length - start, job); } @Override public boolean nextKeyValue() throws IOException, InterruptedException { fileSKVIterator.next(); return fileSKVIterator.hasTop(); } @Override public Key getCurrentKey() throws IOException, InterruptedException { return fileSKVIterator.getTopKey(); } @Override public Value getCurrentValue() throws IOException, InterruptedException { return fileSKVIterator.getTopValue(); } @Override public float getProgress() throws IOException, InterruptedException { return 0; } @Override public void close() throws IOException { //To change body of implemented methods use File | Settings | File Templates. } }; } public static void main(String[] args) { try { Job job = new Job(new Configuration()); job.setJarByClass(AccumuloHDFSFileInputFormat.class); Configuration conf = job.getConfiguration(); conf.setBoolean("mapred.map.tasks.speculative.execution", false); conf.setBoolean("mapred.reduce.tasks.speculative.execution", false); AccumuloInputFormat.setConnectorInfo(job, "root", new PasswordToken("secret")); AccumuloInputFormat.setInputTableName(job, "l_spo"); AccumuloInputFormat.setScanAuthorizations(job, Constants.NO_AUTHS); AccumuloInputFormat.setZooKeeperInstance(job, "acu13", "stratus25:2181"); AccumuloInputFormat.setRanges(job, Collections.singleton(ALLRANGE)); job.setMapperClass(NullMapper.class); job.setNumReduceTasks(0); job.setOutputFormatClass(NullOutputFormat.class); if (args.length == 0) { job.setInputFormatClass(AccumuloHDFSFileInputFormat.class); } else { job.setInputFormatClass(AccumuloInputFormat.class); } job.waitForCompletion(true); } catch (Exception e) { e.printStackTrace(); } } @SuppressWarnings("rawtypes") public static class NullMapper extends Mapper { @Override protected void map(Object key, Object value, Context context) throws IOException, InterruptedException { } } }