Re: Nested Iterations supported in Flink?

2015-04-17 Thread Stephan Ewen
I think running the program multiple times is a reasonable way to start working on this. I would try and see whether this can be re-written to a non-nested iterations case. Nestes iterations algorithms may have much more overhead to start with. Stephan On Tue, Apr 14, 2015 at 3:53 PM, Benoît Ha

Re: Nested Iterations supported in Flink?

2015-04-14 Thread Benoît Hanotte
Thanks for you quick answers! The algorithm is the following: I've got a spatial set of data and I want to find dense regions. The space is beforehand discretized into "cells" of a fixed size. Then, for each dense cell (1st iteration), starting with the most dense, the algorithm tries to ex

Re: Nested Iterations supported in Flink?

2015-04-14 Thread Stephan Ewen
Hi Benoît! You are right, the nested iterations are currently not supported. The test you found actually checks that the Optimizer gives a good error message when encountering nested iterations. Can you write your program as one iterations (the inner) and start the program multiple times to simu

Re: Nested Iterations supported in Flink?

2015-04-14 Thread Till Rohrmann
If your inner iterations happens to work only on the data of a single partition, then you can also implement this iteration as part of a mapPartition operator. The only problem there would be that you have to keep all the partition's data on the heap, if you need access to it. Cheers, Till On Tu

Nested Iterations supported in Flink?

2015-04-13 Thread Benoît Hanotte
Hello, I'm implementing an algorithm which requires nested iterations, and, from what I understood, this feature was not yet available in Flink [1], and my experiments with 2 nested bulk iterations seem to confirm that. However I came across a Flink unit test [2] using nested iterations, so