Nope, you can think about Giraph as MapReduce for graphs. Probably neo4j & C is the way to go for you.
On Wed, Mar 26, 2014 at 3:18 PM, Angelo Immediata <angelo...@gmail.com>wrote: > hi Sebastian > > OK...I got it....I was thinking I could use it for an online scenario...... > Thank you > > Angelo > > > 2014-03-26 14:52 GMT+01:00 Sebastian Schelter <s...@apache.org>: > > Hi Angelo, >> >> It very much depends on your use case. Do you want to precompute paths >> offline in batch or are you looking for a system that answers online? >> Giraph has been built for the first scenario. >> >> --sebastian >> >> >> On 03/26/2014 02:48 PM, Angelo Immediata wrote: >> >>> 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 >>>> >>>> >>>> >>> >> > -- Claudio Martella
