Implement Brandes way of calculating betweenness

The main algorithm is based on SimpleShortestPathsComputation for the main algorithm (brande's algorithm) but I needed to store extra values in each node, and as an effect override the message also.

The trick I've thought about for the algorithm to work is provide the input of nodes in ascending value, starting from 1 to number of nodes, and as such, to complete a bfs each time I have to wait for number of nodes supersteps each time. This can easily be done by mod(superstep,nodes_num).

After the end of that phase I do some calculations in each node, and I clear the distance value, in order to continue running the SimpleShortestPaths algorithm but with the next vertex as a source in ascending order.

I was also based on BrachaTouegDeadlockComputation for overriding message and vertex value,

(message is based on BrachaTouegDeadlockMessage and vertex value on BrachaTouegDeadlockVertexValue located in utils on respect.)

The things I had found difficulty so far is not the algorithm by itself that is the brande's algorithm, but integrating the following things.

1. overriding the value of vertex with mine using myVertex.java Overriding the Serialization functions for my implementation according to BrachaTouegDeadlockVertexValue.

2. overriding the message that a node is passing to another with myMessage.java I've added the accessors that I wanted but I dont now what to do with readFields, and write, that the BrachaTouegDeadlockMessage has, for my implementation

Any help on the above matters is very appreciated. Thank you all, and sorry for the long post So this CAN be done! If this algorithm is effective is another topic of conversation. Thanks for your time, and once again sorry for the long post where everyone with an interest can browse and provide insight, as I have been developing for not very long on giraph and I have not the right experience yet.

Todo: -1) Look at the overrides in my Message 0)Wrapper for the sendMessage GetMessage 1)enable Logger Debug Output 2)Find a way to pass a external global Variable to Giraph(number of nodes) org.apache.hadoop.conf.Configuration org.apache.giraph.conf.LongConfOption; 3) As I have bypassed vertex Value, there must be a way to fix the way output is printed after the computation, for example override giraph.io.VertexWriter 4) In order to permit a vertex to have at least two values, I looked at the example of Bracha where they play with org.apache.hadoop.io.Writable; (I have not yet have the proper background to mess with that)

idea -> change BrachaTouegDeadlockVertexValue

1)override value that a node saves by default a number with a class that supports storing extra parameters, for example, predecessor

2. treximo gia osa superstep osa einai to plithos to komvwn etsi wste na exasfalisoume oti exei ginei h bfs anazhthsh

   number_of_phases= nodes_num

   for number_of_phases for super_steps in range(0, nodes_num) //in essence perform bfs, so there must be at least nodes_num supersteps //in order to update the distance of each node do the shortest path compute and update distance and sigma end source_id=next_source_id (I assume that the nodes have ids in range [0,nodes_num] ) end

3. add value isDiscovered

---utils BrachaTouegMessage Converting Bracha

3)vote to halt after 34*34 supersteps have been perfomed

SimpleShortestPathsComputation extend BasicComputation

<vertex id, vertex value, edge value>

----giraph's main vertex org.apache.giraph.graph.Vertex

some probably useful files to see from giraph code

Max Computation Simple Out Degree Computation simplePageRank Computation