Class CheckpointBarrierTracker

java.lang.Object
org.apache.flink.streaming.runtime.io.checkpointing.CheckpointBarrierHandler
org.apache.flink.streaming.runtime.io.checkpointing.CheckpointBarrierTracker
All Implemented Interfaces:
Closeable, AutoCloseable

@Internal public class CheckpointBarrierTracker extends CheckpointBarrierHandler
The CheckpointBarrierTracker keeps track of what checkpoint barriers have been received from which input channels. Once it has observed all checkpoint barriers for a checkpoint ID, it notifies its listener of a completed checkpoint.

Unlike the SingleCheckpointBarrierHandler, the BarrierTracker does not block the input channels that have sent barriers, so it cannot be used to gain "exactly-once" processing guarantees. It can, however, be used to gain "at least once" processing guarantees.

NOTE: This implementation strictly assumes that newer checkpoints have higher checkpoint IDs.