On Fri, Feb 7, 2014 at 2:30 PM, Claudio Martella <claudio.marte...@gmail.com > wrote:
> > > > On Fri, Feb 7, 2014 at 9:44 AM, Alexander Frolov <alexndr.fro...@gmail.com > > wrote: > >> Thank you, I will try to do this. As I understood I should set number >>> of threads manually through Giraph API. >>> >>> BTW, what is conceptual difference between running multiple workers on >>> the TaskTracker and running single worker and multiple threads? In terms of >>> vertex fetching, memory sharing etc. >>> >> > Basically, better usage of resources: one single JVM, no duplication of > core data structures, less netty threads and communication points, more > locality (less messages over the network), less actors accessing zookeeper > etc. > > >> >>> Also I would like to ask how message transfer between vertices is >> implemented in terms of Hadoop primitives? Source code reference will be >> enough. >> > > Communication does not happen via Hadoop primitives, but ad-hoc via netty. > Ok. It seams that Hadoop has minimalistic influence on Giraph application execution after graph is loaded into memory (that is mapping is done).
