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Posted to commits@flink.apache.org by va...@apache.org on 2016/03/21 19:11:14 UTC
[4/7] flink git commit: [FLINK-3207] [gelly] add a pregel SSSP
example with combiner
[FLINK-3207] [gelly] add a pregel SSSP example with combiner
Project: http://git-wip-us.apache.org/repos/asf/flink/repo
Commit: http://git-wip-us.apache.org/repos/asf/flink/commit/77eb4f0c
Tree: http://git-wip-us.apache.org/repos/asf/flink/tree/77eb4f0c
Diff: http://git-wip-us.apache.org/repos/asf/flink/diff/77eb4f0c
Branch: refs/heads/master
Commit: 77eb4f0c41fe45d3ad4efc8c54f21394cd973cb5
Parents: c5ffb5d
Author: vasia <va...@apache.org>
Authored: Tue Feb 2 12:41:51 2016 +0100
Committer: vasia <va...@apache.org>
Committed: Mon Mar 21 19:10:29 2016 +0100
----------------------------------------------------------------------
.../examples/GSASingleSourceShortestPaths.java | 3 +-
.../SingleSourceShortestPathsITCase.java | 8 +
.../main/java/org/apache/flink/graph/Graph.java | 45 +++++
.../apache/flink/graph/example/PregelSSSP.java | 194 +++++++++++++++++++
4 files changed, 249 insertions(+), 1 deletion(-)
----------------------------------------------------------------------
http://git-wip-us.apache.org/repos/asf/flink/blob/77eb4f0c/flink-libraries/flink-gelly-examples/src/main/java/org/apache/flink/graph/examples/GSASingleSourceShortestPaths.java
----------------------------------------------------------------------
diff --git a/flink-libraries/flink-gelly-examples/src/main/java/org/apache/flink/graph/examples/GSASingleSourceShortestPaths.java b/flink-libraries/flink-gelly-examples/src/main/java/org/apache/flink/graph/examples/GSASingleSourceShortestPaths.java
index 1732016..35f07b0 100755
--- a/flink-libraries/flink-gelly-examples/src/main/java/org/apache/flink/graph/examples/GSASingleSourceShortestPaths.java
+++ b/flink-libraries/flink-gelly-examples/src/main/java/org/apache/flink/graph/examples/GSASingleSourceShortestPaths.java
@@ -36,7 +36,8 @@ import org.apache.flink.graph.utils.Tuple3ToEdgeMap;
* This example shows how to use Gelly's Gather-Sum-Apply iterations.
*
* It is an implementation of the Single-Source-Shortest-Paths algorithm.
- * For a vertex-centric implementation of the same algorithm, please refer to {@link SingleSourceShortestPaths}.
+ * For a scatter-gather implementation of the same algorithm, please refer to {@link SingleSourceShortestPaths}
+ * and for a vertex-centric implementation, see {@link PregelSSSP}.
*
* The input file is a plain text file and must be formatted as follows:
* Edges are represented by tuples of srcVertexId, trgVertexId, distance which are
http://git-wip-us.apache.org/repos/asf/flink/blob/77eb4f0c/flink-libraries/flink-gelly-examples/src/test/java/org/apache/flink/graph/test/examples/SingleSourceShortestPathsITCase.java
----------------------------------------------------------------------
diff --git a/flink-libraries/flink-gelly-examples/src/test/java/org/apache/flink/graph/test/examples/SingleSourceShortestPathsITCase.java b/flink-libraries/flink-gelly-examples/src/test/java/org/apache/flink/graph/test/examples/SingleSourceShortestPathsITCase.java
index faf92c0..258ed16 100644
--- a/flink-libraries/flink-gelly-examples/src/test/java/org/apache/flink/graph/test/examples/SingleSourceShortestPathsITCase.java
+++ b/flink-libraries/flink-gelly-examples/src/test/java/org/apache/flink/graph/test/examples/SingleSourceShortestPathsITCase.java
@@ -24,6 +24,7 @@ import com.google.common.io.Files;
import org.apache.flink.graph.examples.GSASingleSourceShortestPaths;
import org.apache.flink.graph.examples.SingleSourceShortestPaths;
import org.apache.flink.graph.examples.data.SingleSourceShortestPathsData;
+import org.apache.flink.graph.example.PregelSSSP;
import org.apache.flink.test.util.MultipleProgramsTestBase;
import org.apache.flink.test.util.TestBaseUtils;
import org.junit.After;
@@ -75,6 +76,13 @@ public class SingleSourceShortestPathsITCase extends MultipleProgramsTestBase {
expected = SingleSourceShortestPathsData.RESULTED_SINGLE_SOURCE_SHORTEST_PATHS;
}
+ @Test
+ public void testPregelSSSPExample() throws Exception {
+ PregelSSSP.main(new String[]{SingleSourceShortestPathsData.SRC_VERTEX_ID + "",
+ edgesPath, resultPath, 10 + ""});
+ expected = SingleSourceShortestPathsData.RESULTED_SINGLE_SOURCE_SHORTEST_PATHS;
+ }
+
@After
public void after() throws Exception {
TestBaseUtils.compareResultsByLinesInMemory(expected, resultPath);
http://git-wip-us.apache.org/repos/asf/flink/blob/77eb4f0c/flink-libraries/flink-gelly/src/main/java/org/apache/flink/graph/Graph.java
----------------------------------------------------------------------
diff --git a/flink-libraries/flink-gelly/src/main/java/org/apache/flink/graph/Graph.java b/flink-libraries/flink-gelly/src/main/java/org/apache/flink/graph/Graph.java
index ce8e895..f2b5b22 100755
--- a/flink-libraries/flink-gelly/src/main/java/org/apache/flink/graph/Graph.java
+++ b/flink-libraries/flink-gelly/src/main/java/org/apache/flink/graph/Graph.java
@@ -51,6 +51,10 @@ import org.apache.flink.graph.gsa.GSAConfiguration;
import org.apache.flink.graph.gsa.GatherFunction;
import org.apache.flink.graph.gsa.GatherSumApplyIteration;
import org.apache.flink.graph.gsa.SumFunction;
+import org.apache.flink.graph.pregel.ComputeFunction;
+import org.apache.flink.graph.pregel.MessageCombiner;
+import org.apache.flink.graph.pregel.VertexCentricConfiguration;
+import org.apache.flink.graph.pregel.VertexCentricIteration;
import org.apache.flink.graph.spargel.MessagingFunction;
import org.apache.flink.graph.spargel.ScatterGatherConfiguration;
import org.apache.flink.graph.spargel.ScatterGatherIteration;
@@ -1680,6 +1684,47 @@ public class Graph<K, VV, EV> {
}
/**
+ * Runs a VertexCentric iteration on the graph.
+ * No configuration options are provided.
+ *
+ * @param computeFunction the vertex update function
+ * @param combiner an optional message combiner
+ * @param maximumNumberOfIterations maximum number of iterations to perform
+ *
+ * @return the updated Graph after the vertex-centric iteration has converged or
+ * after maximumNumberOfIterations.
+ */
+ public <M> Graph<K, VV, EV> runVertexCentricIteration(
+ ComputeFunction<K, VV, EV, M> computeFunction,
+ MessageCombiner<K, M> combiner, int maximumNumberOfIterations) {
+
+ return this.runVertexCentricIteration(computeFunction, combiner, maximumNumberOfIterations, null);
+ }
+
+ /**
+ * Runs a VetexCentric iteration on the graph with configuration options.
+ *
+ * @param computeFunction the vertex update function
+ * @param combiner an optional message combiner
+ * @param maximumNumberOfIterations maximum number of iterations to perform
+ * @param parameters the iteration configuration parameters
+ *
+ * @return the updated Graph after the vertex-centric iteration has converged or
+ * after maximumNumberOfIterations.
+ */
+ public <M> Graph<K, VV, EV> runVertexCentricIteration(
+ ComputeFunction<K, VV, EV, M> computeFunction,
+ MessageCombiner<K, M> combiner, int maximumNumberOfIterations,
+ VertexCentricConfiguration parameters) {
+
+ VertexCentricIteration<K, VV, EV, M> iteration = VertexCentricIteration.withEdges(
+ edges, computeFunction, maximumNumberOfIterations);
+ iteration.configure(parameters);
+ DataSet<Vertex<K, VV>> newVertices = this.getVertices().runOperation(iteration);
+ return new Graph<K, VV, EV>(newVertices, this.edges, this.context);
+ }
+
+ /**
* @param algorithm the algorithm to run on the Graph
* @param <T> the return type
* @return the result of the graph algorithm
http://git-wip-us.apache.org/repos/asf/flink/blob/77eb4f0c/flink-libraries/flink-gelly/src/main/java/org/apache/flink/graph/example/PregelSSSP.java
----------------------------------------------------------------------
diff --git a/flink-libraries/flink-gelly/src/main/java/org/apache/flink/graph/example/PregelSSSP.java b/flink-libraries/flink-gelly/src/main/java/org/apache/flink/graph/example/PregelSSSP.java
new file mode 100644
index 0000000..93cc360
--- /dev/null
+++ b/flink-libraries/flink-gelly/src/main/java/org/apache/flink/graph/example/PregelSSSP.java
@@ -0,0 +1,194 @@
+/*
+ * 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.flink.graph.example;
+
+import org.apache.flink.api.common.ProgramDescription;
+import org.apache.flink.api.common.functions.MapFunction;
+import org.apache.flink.api.java.DataSet;
+import org.apache.flink.api.java.ExecutionEnvironment;
+import org.apache.flink.graph.Edge;
+import org.apache.flink.graph.Graph;
+import org.apache.flink.graph.Vertex;
+import org.apache.flink.graph.example.utils.SingleSourceShortestPathsData;
+import org.apache.flink.graph.pregel.ComputeFunction;
+import org.apache.flink.graph.pregel.MessageCombiner;
+import org.apache.flink.graph.pregel.MessageIterator;
+import org.apache.flink.graph.utils.Tuple3ToEdgeMap;
+
+/**
+ * This example shows how to use Gelly's Vertex-Centric iterations.
+ *
+ * It is an implementation of the Single-Source-Shortest-Paths algorithm.
+ * For a scatter-gather implementation of the same algorithm, please refer to {@link SingleSourceShortestPaths}
+ * and for a gather-sum-apply implementation see {@link GSASingleSourceShortestPaths}.
+ *
+ * The input file is a plain text file and must be formatted as follows:
+ * Edges are represented by tuples of srcVertexId, trgVertexId, distance which are
+ * separated by tabs. Edges themselves are separated by newlines.
+ * For example: <code>1\t2\t0.1\n1\t3\t1.4\n</code> defines two edges,
+ * edge 1-2 with distance 0.1, and edge 1-3 with distance 1.4.
+ *
+ * If no parameters are provided, the program is run with default data from
+ * {@link org.apache.flink.graph.example.utils.SingleSourceShortestPathsData}
+ */
+public class PregelSSSP implements ProgramDescription {
+
+ public static void main(String[] args) throws Exception {
+
+ if (!parseParameters(args)) {
+ return;
+ }
+
+ ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
+
+ DataSet<Edge<Long, Double>> edges = getEdgesDataSet(env);
+
+ Graph<Long, Double, Double> graph = Graph.fromDataSet(edges, new InitVertices(), env);
+
+ // Execute the vertex-centric iteration
+ Graph<Long, Double, Double> result = graph.runVertexCentricIteration(
+ new SSSPComputeFunction(srcVertexId), new SSSPCombiner(),
+ maxIterations);
+
+ // Extract the vertices as the result
+ DataSet<Vertex<Long, Double>> singleSourceShortestPaths = result.getVertices();
+
+ // emit result
+ if (fileOutput) {
+ singleSourceShortestPaths.writeAsCsv(outputPath, "\n", ",");
+ env.execute("Pregel Single Source Shortest Paths Example");
+ } else {
+ singleSourceShortestPaths.print();
+ }
+
+ }
+
+ // --------------------------------------------------------------------------------------------
+ // Single Source Shortest Path UDFs
+ // --------------------------------------------------------------------------------------------
+
+ @SuppressWarnings("serial")
+ private static final class InitVertices implements MapFunction<Long, Double> {
+
+ public Double map(Long id) { return Double.POSITIVE_INFINITY; }
+ }
+
+ /**
+ * The compute function for SSSP
+ */
+ @SuppressWarnings("serial")
+ public static final class SSSPComputeFunction extends ComputeFunction<Long, Double, Double, Double> {
+
+ private final long srcId;
+
+ public SSSPComputeFunction(long src) {
+ this.srcId = src;
+ }
+
+ public void compute(Vertex<Long, Double> vertex, MessageIterator<Double> messages) {
+
+ double minDistance = (vertex.getId().equals(srcId)) ? 0d : Double.POSITIVE_INFINITY;
+
+ for (Double msg : messages) {
+ minDistance = Math.min(minDistance, msg);
+ }
+
+ if (minDistance < vertex.getValue()) {
+ setNewVertexValue(minDistance);
+ for (Edge<Long, Double> e: getEdges()) {
+ sendMessageTo(e.getTarget(), minDistance + e.getValue());
+ }
+ }
+ }
+ }
+
+ /**
+ * The messages combiner.
+ * Out of all messages destined to a target vertex, only the minimum distance is propagated.
+ */
+ @SuppressWarnings("serial")
+ public static final class SSSPCombiner extends MessageCombiner<Long, Double> {
+
+ public void combineMessages(MessageIterator<Double> messages) {
+
+ double minMessage = Double.POSITIVE_INFINITY;
+ for (Double msg: messages) {
+ minMessage = Math.min(minMessage, msg);
+ }
+ sendCombinedMessage(minMessage);
+ }
+ }
+
+ // ******************************************************************************************************************
+ // UTIL METHODS
+ // ******************************************************************************************************************
+
+ private static boolean fileOutput = false;
+
+ private static Long srcVertexId = 1l;
+
+ private static String edgesInputPath = null;
+
+ private static String outputPath = null;
+
+ private static int maxIterations = 5;
+
+ private static boolean parseParameters(String[] args) {
+
+ if(args.length > 0) {
+ if(args.length != 4) {
+ System.err.println("Usage: PregelSSSP <source vertex id>" +
+ " <input edges path> <output path> <num iterations>");
+ return false;
+ }
+
+ fileOutput = true;
+ srcVertexId = Long.parseLong(args[0]);
+ edgesInputPath = args[1];
+ outputPath = args[2];
+ maxIterations = Integer.parseInt(args[3]);
+ } else {
+ System.out.println("Executing Pregel Single Source Shortest Paths example "
+ + "with default parameters and built-in default data.");
+ System.out.println(" Provide parameters to read input data from files.");
+ System.out.println(" See the documentation for the correct format of input files.");
+ System.out.println("Usage: PregelSSSP <source vertex id>" +
+ " <input edges path> <output path> <num iterations>");
+ }
+ return true;
+ }
+
+ private static DataSet<Edge<Long, Double>> getEdgesDataSet(ExecutionEnvironment env) {
+ if (fileOutput) {
+ return env.readCsvFile(edgesInputPath)
+ .lineDelimiter("\n")
+ .fieldDelimiter("\t")
+ .ignoreComments("%")
+ .types(Long.class, Long.class, Double.class)
+ .map(new Tuple3ToEdgeMap<Long, Double>());
+ } else {
+ return SingleSourceShortestPathsData.getDefaultEdgeDataSet(env);
+ }
+ }
+
+ @Override
+ public String getDescription() {
+ return "Vertex-centric Single Source Shortest Paths";
+ }
+}
\ No newline at end of file