org.apache.flink.streaming.runtime.io

Class CheckpointBarrierTracker

java.lang.Object

org.apache.flink.streaming.runtime.io.CheckpointBarrierHandler

org.apache.flink.streaming.runtime.io.CheckpointBarrierTracker

@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 CheckpointBarrierAligner, 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.

Constructor Summary

Constructors

Constructor and Description
CheckpointBarrierTracker(int totalNumberOfInputChannels)
CheckpointBarrierTracker(int totalNumberOfInputChannels, org.apache.flink.runtime.jobgraph.tasks.AbstractInvokable toNotifyOnCheckpoint)

Method Summary

Modifier and Type	Method and Description
void	checkpointSizeLimitExceeded(long maxBufferedBytes)
long	getAlignmentDurationNanos()
long	getLatestCheckpointId()
boolean	isBlocked(int channelIndex) Checks whether the channel with the given index is blocked.
boolean	processBarrier(org.apache.flink.runtime.io.network.api.CheckpointBarrier receivedBarrier, int channelIndex, long bufferedBytes)
boolean	processCancellationBarrier(org.apache.flink.runtime.io.network.api.CancelCheckpointMarker cancelBarrier)
boolean	processEndOfPartition()
void	releaseBlocksAndResetBarriers()

Methods inherited from class org.apache.flink.streaming.runtime.io.CheckpointBarrierHandler

notifyAbort, notifyAbortOnCancellationBarrier, notifyCheckpoint

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

CheckpointBarrierTracker

public CheckpointBarrierTracker(int totalNumberOfInputChannels)

CheckpointBarrierTracker

public CheckpointBarrierTracker(int totalNumberOfInputChannels,
                                @Nullable
                                org.apache.flink.runtime.jobgraph.tasks.AbstractInvokable toNotifyOnCheckpoint)

Method Detail

releaseBlocksAndResetBarriers

public void releaseBlocksAndResetBarriers()

Specified by:

releaseBlocksAndResetBarriers in class CheckpointBarrierHandler

isBlocked

public boolean isBlocked(int channelIndex)

Description copied from class: CheckpointBarrierHandler

Checks whether the channel with the given index is blocked.

Specified by:

isBlocked in class CheckpointBarrierHandler

Parameters:

channelIndex - The channel index to check.

Returns:

True if the channel is blocked, false if not.

processBarrier

public boolean processBarrier(org.apache.flink.runtime.io.network.api.CheckpointBarrier receivedBarrier,
                              int channelIndex,
                              long bufferedBytes)
                       throws Exception

Specified by:

processBarrier in class CheckpointBarrierHandler

Returns:

true if some blocked data should be unblocked/rolled over.

Throws:

Exception

processCancellationBarrier

public boolean processCancellationBarrier(org.apache.flink.runtime.io.network.api.CancelCheckpointMarker cancelBarrier)
                                   throws Exception

Specified by:

processCancellationBarrier in class CheckpointBarrierHandler

Returns:

true if some blocked data should be unblocked/rolled over.

Throws:

Exception

processEndOfPartition

public boolean processEndOfPartition()
                              throws Exception

Specified by:

processEndOfPartition in class CheckpointBarrierHandler

Returns:

true if some blocked data should be unblocked/rolled over.

Throws:

Exception

getLatestCheckpointId

public long getLatestCheckpointId()

Specified by:

getLatestCheckpointId in class CheckpointBarrierHandler

getAlignmentDurationNanos

public long getAlignmentDurationNanos()

Specified by:

getAlignmentDurationNanos in class CheckpointBarrierHandler

checkpointSizeLimitExceeded

public void checkpointSizeLimitExceeded(long maxBufferedBytes)
                                 throws Exception

Specified by:

checkpointSizeLimitExceeded in class CheckpointBarrierHandler

Throws:

Exception