Hi there In my project I have to implement a routing system with good performance; at the beginning this system should be able in giving routes information only for one italian region (Lombardia) but it could be used for the whole Italy (or world....) Let's stop to the Lombardia for now. By reading OSM files I can create my own graph in the best format i can use it; then I need to use Dijkstra (or any other algorithm) in order to propose to the user K possible paths from point A to point B (K becouse i need to show to the customer also the alternatives). I can't use Contraction Herarchy algorithm becouse I need to take care of external events that can modify the weights on my built graph and this implies that I should create the "contracted" graph once again and this can be a very onerous operation
By my experimentations, I saw that by reading the Lombardia OSM file I should create a graph with around 1 million of vertexes and 6 million of edges and I was thinking to use Giraph to solve my issue (I saw this link http://giraph.apache.org/intro.html where you talked about shortestpaths problem I have a couple of question for you giraph/hadoop gurus - does it make sense to use giraph for my scenario? - must i respect some graph format to pass to the giraph algorithm in order to have K shortest paths from point A to point B? If so....which format should I respect? - what would be perfomance by using giraph? I know that Dijstra algorithm problem is that it is slow.....by using giraph will I be able in improving its performances on very large graph? I know these can seem very basic questions, but I'm pretty new to giraph and I'm trying to understand it Thank you Angelo
