On 29.05.2012 13:13, Paolo Castagna wrote: > Hi Sebastian > > Sebastian Schelter wrote: >> Why do you only recompute the pageRank in each second superstep? Can we >> not use the aggregated value of the dangling nodes from the last superstep? > > I removed the computing of PageRank values every each second superstep. > However, I needed to use a couple of aggregators for the dangling nodes > contribution instead of just one: "dangling-current" and "dangling-previous". > > Each superstep, I need to reset the dangling-current aggregator, at the > same time, I need to know the value of the aggregator at a previous > superstep.
You can save the value from the previous step in a static variable in the WorkerContext before resetting the aggregator. > > I hope it makes sense, let me know if you have a better idea. > >> Overall I think we're on a good way to a robust, real-world PageRank >> implementation, I managed to implement the convergence check with an >> aggregator, will post an updated patch soon. > > I think I've just done it, have a look [1] and let me know if you would have > done it differently. > > Paolo > > [1] > https://github.com/castagna/jena-grande/blob/11f07dd897562f7a4bf8d6e4845128d7f2cdd2ff/src/main/java/org/apache/jena/grande/giraph/pagerank/PageRankVertex.java#L90 > >
