hi Claudio so, if I understood correctly, it has no sense to use Giraph for shortest path calculation in my scenario
Am I right? 2014-03-26 13:27 GMT+01:00 Claudio Martella <claudio.marte...@gmail.com>: > It looks like you're expecting to use Giraph in an online fashion, such as > you would use a database to answer queries within milliseconds or seconds. > Giraph is an offline batch processing system. > > > On Wed, Mar 26, 2014 at 11:11 AM, Angelo Immediata <angelo...@gmail.com>wrote: > >> 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 >> > > > > -- > Claudio Martella > >
