For such a small graph, using a single machine graph processing system makes more sense imho. Should be faster and easier to program. Google for cassovary. Am 26.03.2014 10:12 schrieb "Angelo Immediata" <angelo...@gmail.com>:
> 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 >
