Hi, I am wondering how Google implemented the driving directions function in the Maps. More specifically how did they do it that it is so fast. I asked on Google engineer about this and all he told me is just that there are bunch of MapReduce cycles involved in this process but I don't think it is really close to the truth. How it is possible to implement such real-time function in plain MapReduce fashion (from the Hadoop point of view)? The only possibility I can think of right now it that they either execute the MapReduce computation only in the memory (intermediate results as well as Reduce to next Map results are kept only in some-kind of distributed memory) or they use other architecture for this.
In simple words I know there are some tutorials about how to nail down SSSP problem with MapReduce but I can not believe it can produce results in such a quick response I can experience with Google Maps. Any comments, ideas? Thanks, Lukas
