K
- The type of the key in the bundle mapV
- The type of the value in the bundle mapIN
- Input type for the operator.OUT
- Output type for the operator.public abstract class AbstractMapBundleOperator<K,V,IN,OUT> extends AbstractStreamOperator<OUT> implements OneInputStreamOperator<IN,OUT>, BundleTriggerCallback
AbstractMapBundleOperator
simply used a java Map to store the input elements in
key-value form. The map key is typically the same with the state key, so we can do some
optimizations before accessing states, like pre aggregate values for each key. And we will only
need to access state every key we have, but not every element we processed.
NOTES: if all elements we processed have different keys, such operator will only increase memory footprint, and will not have any performance improvement.
chainingStrategy, config, latencyStats, LOG, metrics, output, processingTimeService
Modifier and Type | Method and Description |
---|---|
void |
close()
This method is called at the very end of the operator's life, both in the case of a
successful completion of the operation, and in the case of a failure and canceling.
|
void |
finish()
This method is called at the end of data processing.
|
void |
finishBundle()
This method is invoked to finish current bundle and start a new one when the trigger was
fired.
|
protected abstract K |
getKey(IN input)
Get the key for current processing element, which will be used as the map bundle's key.
|
void |
open()
This method is called immediately before any elements are processed, it should contain the
operator's initialization logic, e.g. state initialization.
|
void |
prepareSnapshotPreBarrier(long checkpointId)
This method is called when the operator should do a snapshot, before it emits its own
checkpoint barrier.
|
void |
processElement(StreamRecord<IN> element)
Processes one element that arrived on this input of the
MultipleInputStreamOperator . |
void |
processWatermark(Watermark mark)
Processes a
Watermark that arrived on the first input of this two-input operator. |
getChainingStrategy, getContainingTask, getCurrentKey, getExecutionConfig, getInternalTimerService, getKeyedStateBackend, getKeyedStateStore, getMetricGroup, getOperatorConfig, getOperatorID, getOperatorName, getOperatorStateBackend, getOrCreateKeyedState, getPartitionedState, getPartitionedState, getProcessingTimeService, getRuntimeContext, getTimeServiceManager, getUserCodeClassloader, hasKeyContext1, hasKeyContext2, initializeState, initializeState, isUsingCustomRawKeyedState, notifyCheckpointAborted, notifyCheckpointComplete, processLatencyMarker, processLatencyMarker1, processLatencyMarker2, processWatermark1, processWatermark2, processWatermarkStatus, processWatermarkStatus1, processWatermarkStatus2, reportOrForwardLatencyMarker, setChainingStrategy, setCurrentKey, setKeyContextElement1, setKeyContextElement2, setProcessingTimeService, setup, snapshotState, snapshotState
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
setKeyContextElement
getMetricGroup, getOperatorID, initializeState, setKeyContextElement1, setKeyContextElement2, snapshotState
notifyCheckpointAborted, notifyCheckpointComplete
getCurrentKey, setCurrentKey
processLatencyMarker, processWatermarkStatus
hasKeyContext
public void open() throws Exception
AbstractStreamOperator
The default implementation does nothing.
open
in interface StreamOperator<OUT>
open
in class AbstractStreamOperator<OUT>
Exception
- An exception in this method causes the operator to fail.public void processElement(StreamRecord<IN> element) throws Exception
Input
MultipleInputStreamOperator
.
This method is guaranteed to not be called concurrently with other methods of the operator.processElement
in interface Input<IN>
Exception
protected abstract K getKey(IN input) throws Exception
Exception
public void finishBundle() throws Exception
BundleTriggerCallback
finishBundle
in interface BundleTriggerCallback
Exception
- This method may throw exceptions. Throwing an exception will cause the
operation to fail and may trigger recovery.public void processWatermark(Watermark mark) throws Exception
Input
Watermark
that arrived on the first input of this two-input operator.
This method is guaranteed to not be called concurrently with other methods of the operator.processWatermark
in interface Input<IN>
processWatermark
in class AbstractStreamOperator<OUT>
Exception
Watermark
public void prepareSnapshotPreBarrier(long checkpointId) throws Exception
StreamOperator
This method is intended not for any actual state persistence, but only for emitting some data before emitting the checkpoint barrier. Operators that maintain some small transient state that is inefficient to checkpoint (especially when it would need to be checkpointed in a re-scalable way) but can simply be sent downstream before the checkpoint. An example are opportunistic pre-aggregation operators, which have small the pre-aggregation state that is frequently flushed downstream.
Important: This method should not be used for any actual state snapshot logic, because it will inherently be within the synchronous part of the operator's checkpoint. If heavy work is done within this method, it will affect latency and downstream checkpoint alignments.
prepareSnapshotPreBarrier
in interface StreamOperator<OUT>
prepareSnapshotPreBarrier
in class AbstractStreamOperator<OUT>
checkpointId
- The ID of the checkpoint.Exception
- Throwing an exception here causes the operator to fail and go into
recovery.public void finish() throws Exception
StreamOperator
The method is expected to flush all remaining buffered data. Exceptions during this flushing of buffered data should be propagated, in order to cause the operation to be recognized as failed, because the last data items are not processed properly.
After this method is called, no more records can be produced for the downstream operators.
WARNING: It is not safe to use this method to commit any transactions or other side
effects! You can use this method to flush any buffered data that can later on be committed
e.g. in a CheckpointListener.notifyCheckpointComplete(long)
.
NOTE:This method does not need to close any resources. You should release external
resources in the StreamOperator.close()
method.
finish
in interface StreamOperator<OUT>
finish
in class AbstractStreamOperator<OUT>
Exception
- An exception in this method causes the operator to fail.public void close() throws Exception
StreamOperator
This method is expected to make a thorough effort to release all resources that the operator has acquired.
NOTE:It can not emit any records! If you need to emit records at the end of
processing, do so in the StreamOperator.finish()
method.
close
in interface StreamOperator<OUT>
close
in class AbstractStreamOperator<OUT>
Exception
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