Hi Shivani,

why are you using a vertex-centric iteration to compute the approximate
Adamic-Adar?
It's not an iterative computation :)

In fact, it should be as complex (in terms of operators) as the exact
Adamic-Adar, only more efficient because of the different neighborhood
representation. Are you having the same problem with the exact computation?

Cheers,
Vasia.

On 20 July 2015 at 14:41, Maximilian Michels <[email protected]> wrote:

> Hi Shivani,
>
> The issue is that by the time the Hash Join is executed, the
> MutableHashTable cannot allocate enough memory segments. That means that
> your other operators are occupying them. It is fine that this also occurs
> on Travis because the workers there have limited memory as well.
>
> Till suggested to change the memory fraction through the
> ExuectionEnvironment. Can you try that?
>
> Cheers,
> Max
>
> On Mon, Jul 20, 2015 at 2:23 PM, Shivani Ghatge <[email protected]>
> wrote:
>
>> Hello Maximilian,
>>
>> Thanks for the suggestion. I will use it to check the program. But when I
>> am creating a PR for the same implementation with a Test, I am getting the
>> same error even on Travis build. So for that what would be the solution?
>>
>> Here is my PR https://github.com/apache/flink/pull/923
>> And here is the Travis build status
>> https://travis-ci.org/apache/flink/builds/71695078
>>
>> Also on the IDE it is working fine in Collection execution mode.
>>
>> Thanks and Regards,
>> Shivani
>>
>> On Mon, Jul 20, 2015 at 2:14 PM, Maximilian Michels <[email protected]>
>> wrote:
>>
>>> 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 <[email protected]>
>>> 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?
>>>>
>>>
>>>
>>
>

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