Dear Sir： I am a beginner of Flink and very interested in “Exactly-once” Recovery Mechanism. I have a question about processing sequence problem of tuples. For example, in Fig 1, process unit A runs JOIN, and the size of sliding window is 4. At the beginning, the state of sliding windows is shown in Fig 2. Before A failed, Tuples came in the order of 1,2,3,4,and the join results are (1,1),(2,2)(2,2)(3,3)(4,4),but after A failed and the state is reset to Snap(x), tuples came in the order of 3,4,1,2. This time the join results are (3,3)(3,3)(4,4)(2,2)(2,2). [cid:image001.png@01D0EA37.0E67AA00] Fig 1 [cid:image002.png@01D0EA37.0E67AA00] Fig 2 I wonder how Flink’s mechanism guarantees the consistency of results or consistency of tuples’ sequence?
Thank you very much.
