I'm trying to implement a graph algorithm that does a form of path searching. Once a certain criteria is met on any path in the graph, I wanted to halt the rest of the iterations. But I can't see how to do that with the Pregel API, since any vertex isn't able to know the state of other arbitrary vertex (if they're not adjacent).
Is there a common pattern for doing something like this? I was thinking of using a custom accumulator where the zero is true and the addInPlace is a boolean or. Each vertex (as part of its vprog) could add to the accumulator, and once a path is found which meets the condition, the accumulator would then have a value of false. But since workers can't read accumulators, I don't see how to use that when knowing whether to iterate again. That is, unless I reimplement the Pregel class with the added check when iterating... Any suggestions? Thanks in advance!
