Hi, We are trying to parallelize the ant colony optimization algorithm for TSP over hadoop and are facing some issues. We are using TSPLIB as input files. The input is a text file containing eucledian coordinates of the cities - first column is city number and the next two columns contain the x and y coordinates respectively.
What we intend to do is to take input from this single file, send copies of it to multiple mappers (each mapper acts like the ant in the algorithm), each mapper works on its input to find its own TSP solution that it outputs and finally the reducer outputs the smallest tour found by the mappers. Hope we are in the right track. Here are the issues: 1) Since the input file is small, we need to force hadoop to fire up multiple map tasks by replicating the input. How can we make an InputSplit of the whole file and replicate it so that the input can be sent to multiple mappers? 2) the algorithm uses a shared pheromone array and each mapper needs to read and write data from this. How can we share the pheromone data across the mappers. Hope the questions are clear enough. Any help would be greatly appreciated. Thank you Regards Sharat
