Re: About Interplay of Merged Streams, Output Selectors and Checkpoint Barriers (and Watermarks)

2015-05-12 Thread Stephan Ewen
Watermarks also don't need to flush buffers, they can actually simply queue in as special stream records, if we want to. On Tue, May 12, 2015 at 2:53 PM, Gyula Fóra wrote: > Its actually a very different mechanism as watermarks will not block the > computations > > On Tue, May 12, 2015 at 2:48 P

Re: About Interplay of Merged Streams, Output Selectors and Checkpoint Barriers (and Watermarks)

2015-05-12 Thread Aljoscha Krettek
What Stephan mentioned is exactly how I'm planning to implement it, yes. How do the barriers work with chained tasks and OutputSelectorS? Or is there no special-case code required? On Tue, May 12, 2015 at 2:53 PM, Gyula Fóra wrote: > Its actually a very different mechanism as watermarks will not

Re: About Interplay of Merged Streams, Output Selectors and Checkpoint Barriers (and Watermarks)

2015-05-12 Thread Gyula Fóra
Its actually a very different mechanism as watermarks will not block the computations On Tue, May 12, 2015 at 2:48 PM, Matthias J. Sax < mj...@informatik.hu-berlin.de> wrote: > Hi, > > I don't understand why we need the same machnism twice in the code... > Could checkpoing barrieres and low water

Re: About Interplay of Merged Streams, Output Selectors and Checkpoint Barriers (and Watermarks)

2015-05-12 Thread Matthias J. Sax
Hi, I don't understand why we need the same machnism twice in the code... Could checkpoing barrieres and low watermarks be unified (or one build on-top/by-using the other) -Matthias On 05/12/2015 02:47 PM, Gyula Fóra wrote: > Hi, > > Checkpoint barriers are handled directly on top of the netwo

Re: About Interplay of Merged Streams, Output Selectors and Checkpoint Barriers (and Watermarks)

2015-05-12 Thread Stephan Ewen
I would like to refrain from adding additional tasks as much as possible. I agree with Gyula that extending the reader to track watermarks and call a handler whenever the watermark advances would be a nice way to implement this. On Tue, May 12, 2015 at 2:40 PM, Aljoscha Krettek wrote: > Hi Folk

Re: About Interplay of Merged Streams, Output Selectors and Checkpoint Barriers (and Watermarks)

2015-05-12 Thread Gyula Fóra
Hi, Checkpoint barriers are handled directly on top of the network layer and you are right they work similarly, by blocking input channels until it gets the barrier from all of them. A way of implementing this on the operator level would be by adding a way to ask the inputreader the channel index

About Interplay of Merged Streams, Output Selectors and Checkpoint Barriers (and Watermarks)

2015-05-12 Thread Aljoscha Krettek
Hi Folks, as I said in the subject. How will this work? I'm in the process about thinking how to implement low watermarks in Streaming. I'm thinking that the implementation should be quite similar to how the checkpointing barriers will be implemented since they also flush out stuff. Now I'm wonder