Hello all, I am planning to work on removing the old BundleBasedDirectRunner, and expand the FnApiRunner to work on streaming as well as batch. Currently, the FnApiRunner orders the processing graph topologically, and "pushes" all the data through each stage in topological order (deferred inputs such as residuals and timers are immediately pushed to the SDK as well). The new design would change from this push-all-data-through-topologically-sorted-stages model to having queues for "bundles", or for elements that are awaiting processing, and routing them to the appropriate bundle processing subgraph.
The design is here: http://s.apache.org/streaming-fn-runner-py I expect I'd appreciate comments and everything : ) Best -P.
