thanks !
On Tue, Aug 6, 2013 at 10:48 AM, Avery Ching <ach...@apache.org> wrote: > The Giraph/Pregel model is based on bulk synchronous parallel computing, > where the programmer is abstracted from the details of how the > parallelization occurs (infrastructure does this for you). Additionally > the APIs are built for graph-processing. Since the computing model is well > defined (BSP), the infrastructure can checkpoint the state of the > application at the appropriate time and also handle failures without user > interaction. > > MPI is a much lower level and generic API, where messages are send to > processes. Users must pack/unpack their own messages and deliver messages > to the appropriate data structures. Users must partition their own data. > As of MPI 2, the state of a failed process leaves the application in an > undefined state (usually dead). > > Hope that helps, > > Avery > > > On 8/6/13 10:19 AM, Yang wrote: > >> it seems that the paradigm offered by Giraph/Pregel is very similar to >> the programming paradim of PVM , and to a lesser degree, MPI. using PVM, we >> often engages in such "iterative cycles" where all the nodes sync on a >> barrier and then enters the next cycle. >> >> so what is the extra features offered by Giraph/Pregel? I can see >> persistence/restarting of tasks, and maybe abstraction of the >> user-code-specific part into the API so that users are not concerned with >> the actual message passing (message passing is done by the framework). >> >> Thanks >> Yang >> > >
