Re: Too few memory segments provided exception

Posted by Maximilian Michels on
URL: http://deprecated-apache-flink-user-mailing-list-archive.369.s1.nabble.com/Too-few-memory-segments-provided-exception-tp2176p2177.html

Hi Shivani,

Flink doesn't have enough memory to perform a hash join. You need to provide Flink with more memory. You can either increase the "taskmanager.heap.mb" config variable or set "taskmanager.memory.fraction" to some value greater than 0.7 and smaller then 1.0. The first config variable allocates more overall memory for Flink; the latter changes the ratio between Flink managed memory (e.g. for hash join) and user memory (for you functions and Gelly's code).

If you run this inside an IDE, the memory is configured automatically and you don't have control over that at the moment. You could, however, start a local cluster (./bin/start-local) after you adjusted your flink-conf.yaml and run your programs against that configured cluster. You can do that either through your IDE using a RemoteEnvironment or by submitting the packaged JAR to the local cluster using the command-line tool (./bin/flink).

Hope that helps.

Cheers,

Max

On Mon, Jul 20, 2015 at 2:04 PM, Shivani Ghatge <[hidden email]> wrote:

Hello,

 I am working on a problem which implements Adamic Adar Algorithm using Gelly.

I am running into this exception for all the Joins (including the one that are part of the reduceOnNeighbors function)

Too few memory segments provided. Hash Join needs at least 33 memory segments.

The problem persists even when I comment out some of the joins.

Even after using edg = edg.join(graph.getEdges(), JoinOperatorBase.JoinHint.BROADCAST_HASH_SECOND).where(0,1).equalTo(0,1).with(new JoinEdge());

as suggested by @AndraLungu the problem persists.

The code is


DataSet<Tuple2<Long, Long>> degrees = graph.getDegrees();

        //get neighbors of each vertex in the HashSet for it's value
        computedNeighbors = graph.reduceOnNeighbors(new GatherNeighbors(), EdgeDirection.ALL);
       
        //get vertices with updated values for the final Graph which will be used to get Adamic Edges
        Vertices = computedNeighbors.join(degrees, JoinOperatorBase.JoinHint.BROADCAST_HASH_FIRST).where(0).equalTo(0).with(new JoinNeighborDegrees());

        Graph<Long, Tuple3<Double, HashSet<Long>, List<Tuple3<Long, Long, Double>>>, Double> updatedGraph =
                Graph.fromDataSet(Vertices, edges, env);
       
        //configure Vertex Centric Iteration
        VertexCentricConfiguration parameters = new VertexCentricConfiguration();

        parameters.setName("Find Adamic Adar Edge Weights");

        parameters.setDirection(EdgeDirection.ALL);
       
        //run Vertex Centric Iteration to get the Adamic Adar Edges into the vertex Value
        updatedGraph = updatedGraph.runVertexCentricIteration(new GetAdamicAdarEdges<Long>(), new NeighborsMessenger<Long>(), 1, parameters);
       
        //Extract Vertices of the updated graph
        DataSet<Vertex<Long, Tuple3<Double, HashSet<Long>, List<Tuple3<Long, Long, Double>>>>> vertices = updatedGraph.getVertices();
       
        //Extract the list of Edges from the vertex values
        DataSet<Tuple3<Long, Long, Double>> edg = vertices.flatMap(new GetAdamicList());
       
        //Partial weights for the edges are added
        edg = edg.groupBy(0,1).reduce(new AdamGroup());

        //Graph is updated with the Adamic Adar Edges
        edg = edg.join(graph.getEdges(), JoinOperatorBase.JoinHint.BROADCAST_HASH_SECOND).where(0,1).equalTo(0,1).with(new JoinEdge());

Any idea how I could tackle this Exception?