Hey Gyula, the BlockingBackChannel is only used for data feedback. The synchronization happens with a separate barrier called SuperstepBarrier. (For delta iterations there is also a further SolutionSetUpdateBarrier). But this are more "runtime hacks" (the DAG still looks like a DAG to the execution engine) and you would have to think about how to model this stuff for streams.
Best, Ufuk On 09 Jul 2014, at 10:14, Gyula Fóra <[email protected]> wrote: > Hey, > > So we started digging through the IterativeDataSet and it seems like you > are using the BlockingBackChannel as this special feedback edge. Does it > work as a synchronization barrier would in BSP? If so it is probably not > suitable for processing continuous dataflows is it? > > Gyula > > > > > On Tue, Jul 8, 2014 at 4:33 PM, Stephan Ewen <[email protected]> wrote: > >> Cyclic graphs are a problem for both the scheduler and the >> currently-under-works recovery logic. >> >> General cyclic graphs are a bit of a design problem. >> >> I think what we need in the future is something like a special feedback >> edge that closes the cycle and that is synchronized (in batches / >> generations) to make it transparent to the recovery and scheduling logic. >> >> Stephan >>
