In Flink, the checkpoint mechanism can ensure that when the application fails during operation, it recovers from a certain checkpoint. During this process, stream snapshots are created sequentially…

Question

Options

• ATrue
• BFalse

• A
  76% (25)
• B
  24% (8)

Explanation

Option A is correct because Flink's checkpoint mechanism uses checkpoint barriers - special markers injected into the data stream that flow downstream in the exact same order as the incoming data records. When a checkpoint is triggered, these barriers travel through the stream sequentially, causing each operator to snapshot its state only after processing all records that arrived before the barrier, preserving strict data-order consistency.

Since the barriers respect the inflow order of data, the resulting snapshots capture a globally consistent state aligned with that order - meaning recovery replays data from a well-defined, ordered point, not an arbitrary one. Option B (False) is incorrect because it would imply snapshots could be taken in arbitrary or out-of-order fashion, which would break consistency guarantees and make recovery unreliable.

Memory tip: Think of a checkpoint barrier like a "timestamp flag" racing through a conveyor belt of data - it never overtakes the items ahead of it, so every snapshot is always taken in line with the data flow order.

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