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ASF GitHub Bot commented on FLINK-1514: --------------------------------------- Github user vasia commented on a diff in the pull request: https://github.com/apache/flink/pull/408#discussion_r28645507 --- Diff: flink-staging/flink-gelly/src/main/java/org/apache/flink/graph/example/GSAConnectedComponentsExample.java --- @@ -0,0 +1,190 @@ +/* + * 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.FlatMapFunction; +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.api.java.tuple.Tuple2; +import org.apache.flink.graph.Edge; +import org.apache.flink.graph.Graph; +import org.apache.flink.graph.Vertex; +import org.apache.flink.graph.gsa.ApplyFunction; +import org.apache.flink.graph.gsa.GatherFunction; +import org.apache.flink.graph.gsa.SumFunction; +import org.apache.flink.graph.gsa.RichEdge; +import org.apache.flink.types.NullValue; +import org.apache.flink.util.Collector; + +/** + * This is an implementation of the Connected Components algorithm, using a gather-sum-apply iteration + */ +public class GSAConnectedComponentsExample implements ProgramDescription { + + // -------------------------------------------------------------------------------------------- + // Program + // -------------------------------------------------------------------------------------------- + + public static void main(String[] args) throws Exception { + + if (!parseParameters(args)) { + return; + } + + ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment(); + + DataSet<Edge<Long, NullValue>> edges = getEdgeDataSet(env); + DataSet<Vertex<Long, Long>> vertices = edges.flatMap(new InitVerticesMapper()).distinct(); + + Graph<Long, Long, NullValue> graph = Graph.fromDataSet(vertices, edges, env); + + // Simply return the vertex value of each vertex + GatherFunction<Long, NullValue, Long> gather = new ConnectedComponentsGather(); + + // Select the lower value among neighbors + SumFunction<Long, NullValue, Long> sum = new ConnectedComponentsSum(); + + // Set the lower value for each vertex + ApplyFunction<Long, NullValue, Long> apply = new ConnectedComponentsApply(); + + // Execute the GSA iteration + Graph<Long, Long, NullValue> result = + graph.runGatherSumApplyIteration(gather, sum, apply, maxIterations); + + // Extract the vertices as the result + DataSet<Vertex<Long, Long>> greedyGraphColoring = result.getVertices(); --- End diff -- greedyGraphColoring? > [Gelly] Add a Gather-Sum-Apply iteration method > ----------------------------------------------- > > Key: FLINK-1514 > URL: https://issues.apache.org/jira/browse/FLINK-1514 > Project: Flink > Issue Type: New Feature > Components: Gelly > Affects Versions: 0.9 > Reporter: Vasia Kalavri > Assignee: Daniel Bali > > This will be a method that implements the GAS computation model, but without > the "scatter" step. The phases can be mapped into the following steps inside > a delta iteration: > gather: a map on each < srcVertex, edge, trgVertex > that produces a partial > value > sum: a reduce that combines the partial values > apply: join with vertex set to update the vertex values using the results of > sum and the previous state. -- This message was sent by Atlassian JIRA (v6.3.4#6332)