Is it a requirement to use map reduce? Also how does mahout play into this? Potentially you could build mappers that could reference an in memory graph and have an API that pre calculates dijkstra or astar up front. You could then add or remove a node as part of the reduce process that references this graph and recalculates dijkstra or astar in a closed feedback loop. However its not obvious to me that mapreduce is the appropriate tool to do this.
Some more context into the problem and how mahout fits in would be great. Sent from my iPhone On Apr 20, 2012, at 8:56 AM, Mike Spreitzer <mspre...@us.ibm.com> wrote: > I am wondering what is the best way to do this using map-reduce. Both for > the special case of only adding edges, and the general case where edges > may be removed. > > Thanks, > Mike > > > > From: Saikat Kanjilal <sxk1...@hotmail.com> > To: "user@mahout.apache.org" <user@mahout.apache.org> > Date: 04/20/2012 11:46 AM > Subject: Re: shortest-path maintenance > > > > Hi Mike, > Neo4j does this and is meant for this (www.neo4j.org) type of calculation. > Are you looking to solve this within a particular algorithm in mahout? > > Regards > > Sent from my iPhone > > On Apr 20, 2012, at 8:28 AM, Mike Spreitzer <mspre...@us.ibm.com> wrote: > >> Is there something in Mahout that maintains shortest paths (or simply >> distance) from a distinguished vertex in a graph? That is, given a > graph >> in which this problem has been solved, and a small change in that graph, > >> something that will efficiently find the answers for the graph after the > >> small change? >> >> Thanks, >> Mike > >
