| /* |
| * 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.giraph.examples; |
| |
| import org.apache.giraph.graph.BasicComputation; |
| import org.apache.giraph.examples.SimpleSuperstepComputation.SimpleSuperstepVertexInputFormat; |
| import org.apache.giraph.graph.Vertex; |
| import org.apache.giraph.job.GiraphJob; |
| import org.apache.giraph.worker.WorkerContext; |
| import org.apache.hadoop.conf.Configuration; |
| import org.apache.hadoop.fs.FileSystem; |
| import org.apache.hadoop.fs.Path; |
| import org.apache.hadoop.io.DoubleWritable; |
| import org.apache.hadoop.io.FloatWritable; |
| import org.apache.hadoop.io.IntWritable; |
| import org.apache.hadoop.io.LongWritable; |
| import org.apache.hadoop.mapreduce.Mapper.Context; |
| import org.apache.hadoop.util.Tool; |
| import org.apache.hadoop.util.ToolRunner; |
| |
| import java.io.DataOutputStream; |
| import java.io.IOException; |
| |
| /** |
| * Fully runnable example of how to |
| * emit worker data to HDFS during a graph |
| * computation. |
| */ |
| public class SimpleVertexWithWorkerContext implements Tool { |
| /** Directory name of where to write. */ |
| public static final String OUTPUTDIR = "svwwc.outputdir"; |
| /** Halting condition for the number of supersteps */ |
| private static final int TESTLENGTH = 30; |
| /** Configuration */ |
| private Configuration conf; |
| |
| @Override |
| public void setConf(Configuration conf) { |
| this.conf = conf; |
| } |
| |
| @Override |
| public Configuration getConf() { |
| return conf; |
| } |
| |
| /** |
| * Actual vetex implementation |
| */ |
| public static class SimpleComputation extends BasicComputation<LongWritable, |
| IntWritable, FloatWritable, DoubleWritable> { |
| @Override |
| public void compute( |
| Vertex<LongWritable, IntWritable, FloatWritable> vertex, |
| Iterable<DoubleWritable> messages) throws IOException { |
| |
| long superstep = getSuperstep(); |
| |
| if (superstep < TESTLENGTH) { |
| EmitterWorkerContext emitter = getWorkerContext(); |
| emitter.emit("vertexId=" + vertex.getId() + |
| " superstep=" + superstep + "\n"); |
| } else { |
| vertex.voteToHalt(); |
| } |
| } |
| } |
| |
| /** |
| * Example worker context to emit data as part of a superstep. |
| */ |
| @SuppressWarnings("rawtypes") |
| public static class EmitterWorkerContext extends WorkerContext { |
| /** File name prefix */ |
| private static final String FILENAME = "emitter_"; |
| /** Output stream to dump the strings. */ |
| private DataOutputStream out; |
| |
| @Override |
| public void preApplication() { |
| Context context = getContext(); |
| FileSystem fs; |
| |
| try { |
| fs = FileSystem.get(context.getConfiguration()); |
| |
| String p = context.getConfiguration() |
| .get(SimpleVertexWithWorkerContext.OUTPUTDIR); |
| if (p == null) { |
| throw new IllegalArgumentException( |
| SimpleVertexWithWorkerContext.OUTPUTDIR + |
| " undefined!"); |
| } |
| |
| Path path = new Path(p); |
| if (!fs.exists(path)) { |
| throw new IllegalArgumentException(path + |
| " doesn't exist"); |
| } |
| |
| Path outF = new Path(path, FILENAME + |
| context.getTaskAttemptID()); |
| if (fs.exists(outF)) { |
| throw new IllegalArgumentException(outF + |
| " aready exists"); |
| } |
| |
| out = fs.create(outF); |
| } catch (IOException e) { |
| throw new RuntimeException( |
| "can't initialize WorkerContext", e); |
| } |
| } |
| |
| @Override |
| public void postApplication() { |
| if (out != null) { |
| try { |
| out.flush(); |
| out.close(); |
| } catch (IOException e) { |
| throw new RuntimeException( |
| "can't finalize WorkerContext", e); |
| } |
| out = null; |
| } |
| } |
| |
| @Override |
| public void preSuperstep() { } |
| |
| @Override |
| public void postSuperstep() { } |
| |
| /** |
| * Write this string to the output stream. |
| * |
| * @param s String to dump. |
| */ |
| public void emit(String s) { |
| try { |
| out.writeUTF(s); |
| } catch (IOException e) { |
| throw new RuntimeException("can't emit", e); |
| } |
| } |
| } |
| |
| @Override |
| public int run(String[] args) throws Exception { |
| if (args.length != 2) { |
| throw new IllegalArgumentException( |
| "run: Must have 2 arguments <output path> <# of workers>"); |
| } |
| GiraphJob job = new GiraphJob(getConf(), getClass().getName()); |
| job.getConfiguration().setComputationClass(SimpleComputation.class); |
| job.getConfiguration().setVertexInputFormatClass( |
| SimpleSuperstepVertexInputFormat.class); |
| job.getConfiguration().setWorkerContextClass(EmitterWorkerContext.class); |
| job.getConfiguration().set( |
| SimpleVertexWithWorkerContext.OUTPUTDIR, args[0]); |
| job.getConfiguration().setWorkerConfiguration(Integer.parseInt(args[1]), |
| Integer.parseInt(args[1]), |
| 100.0f); |
| if (job.run(true)) { |
| return 0; |
| } else { |
| return -1; |
| } |
| } |
| |
| /** |
| * Executable from the command line. |
| * |
| * @param args Command line arguments. |
| * @throws Exception |
| */ |
| public static void main(String[] args) throws Exception { |
| System.exit(ToolRunner.run(new SimpleVertexWithWorkerContext(), args)); |
| } |
| } |