OUT
- The output type of the operator.@PublicEvolving public abstract class AbstractStreamOperator<OUT> extends Object implements StreamOperator<OUT>, SetupableStreamOperator<OUT>, StreamOperatorStateHandler.CheckpointedStreamOperator, Serializable
AbstractUdfStreamOperator
instead (which is a specialized subclass of this class).
For concrete implementations, one of the following two interfaces must also be implemented, to
mark the operator as unary or binary: OneInputStreamOperator
or TwoInputStreamOperator
.
Methods of StreamOperator
are guaranteed not to be called concurrently. Also, if using
the timer service, timer callbacks are also guaranteed not to be called concurrently with methods
on StreamOperator
.
Note, this class is going to be removed and replaced in the future by AbstractStreamOperatorV2
. However as AbstractStreamOperatorV2
is currently experimental,
AbstractStreamOperator
has not been deprecated just yet.
Modifier and Type | Field and Description |
---|---|
protected ChainingStrategy |
chainingStrategy |
protected StreamConfig |
config |
protected LatencyStats |
latencyStats |
protected static org.slf4j.Logger |
LOG
The logger used by the operator class and its subclasses.
|
protected OperatorMetricGroup |
metrics
Metric group for the operator.
|
protected Output<StreamRecord<OUT>> |
output |
protected ProcessingTimeService |
processingTimeService |
Constructor and Description |
---|
AbstractStreamOperator() |
Modifier and Type | Method and Description |
---|---|
void |
close()
This method is called after all records have been added to the operators via the methods
OneInputStreamOperator.processElement(StreamRecord) , or TwoInputStreamOperator.processElement1(StreamRecord) and TwoInputStreamOperator.processElement2(StreamRecord) . |
void |
dispose()
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.
|
ChainingStrategy |
getChainingStrategy() |
StreamTask<?,?> |
getContainingTask() |
Object |
getCurrentKey() |
ExecutionConfig |
getExecutionConfig()
Gets the execution config defined on the execution environment of the job to which this
operator belongs.
|
<K,N> InternalTimerService<N> |
getInternalTimerService(String name,
TypeSerializer<N> namespaceSerializer,
Triggerable<K,N> triggerable)
Returns a
InternalTimerService that can be used to query current processing time and
event time and to set timers. |
<K> KeyedStateBackend<K> |
getKeyedStateBackend() |
KeyedStateStore |
getKeyedStateStore() |
MetricGroup |
getMetricGroup() |
StreamConfig |
getOperatorConfig() |
OperatorID |
getOperatorID() |
protected String |
getOperatorName()
Return the operator name.
|
OperatorStateBackend |
getOperatorStateBackend() |
protected <N,S extends State,T> |
getOrCreateKeyedState(TypeSerializer<N> namespaceSerializer,
StateDescriptor<S,T> stateDescriptor) |
protected <S extends State,N> |
getPartitionedState(N namespace,
TypeSerializer<N> namespaceSerializer,
StateDescriptor<S,?> stateDescriptor)
Creates a partitioned state handle, using the state backend configured for this task.
|
protected <S extends State> |
getPartitionedState(StateDescriptor<S,?> stateDescriptor)
Creates a partitioned state handle, using the state backend configured for this task.
|
ProcessingTimeService |
getProcessingTimeService()
Returns the
ProcessingTimeService responsible for getting the current processing time
and registering timers. |
StreamingRuntimeContext |
getRuntimeContext()
Returns a context that allows the operator to query information about the execution and also
to interact with systems such as broadcast variables and managed state.
|
protected Optional<InternalTimeServiceManager<?>> |
getTimeServiceManager() |
ClassLoader |
getUserCodeClassloader() |
void |
initializeState(StateInitializationContext context)
Stream operators with state which can be restored need to override this hook method.
|
void |
initializeState(StreamTaskStateInitializer streamTaskStateManager)
Provides a context to initialize all state in the operator.
|
protected boolean |
isUsingCustomRawKeyedState()
Indicates whether or not implementations of this class is writing to the raw keyed state
streams on snapshots, using
snapshotState(StateSnapshotContext) . |
void |
notifyCheckpointAborted(long checkpointId)
This method is called as a notification once a distributed checkpoint has been aborted.
|
void |
notifyCheckpointComplete(long checkpointId)
This method is called as a notification once a distributed checkpoint has been completed.
|
int |
numEventTimeTimers() |
int |
numProcessingTimeTimers() |
void |
open()
This method is called immediately before any elements are processed, it should contain the
operator's initialization logic, e.g.
|
void |
prepareSnapshotPreBarrier(long checkpointId)
This method is called when the operator should do a snapshot, before it emits its own
checkpoint barrier.
|
void |
processLatencyMarker(LatencyMarker latencyMarker) |
void |
processLatencyMarker1(LatencyMarker latencyMarker) |
void |
processLatencyMarker2(LatencyMarker latencyMarker) |
void |
processWatermark(Watermark mark) |
void |
processWatermark1(Watermark mark) |
void |
processWatermark2(Watermark mark) |
protected void |
reportOrForwardLatencyMarker(LatencyMarker marker) |
void |
setChainingStrategy(ChainingStrategy strategy) |
void |
setCurrentKey(Object key) |
void |
setKeyContextElement1(StreamRecord record) |
void |
setKeyContextElement2(StreamRecord record) |
void |
setProcessingTimeService(ProcessingTimeService processingTimeService)
Deprecated.
The
ProcessingTimeService instance should be passed by the operator
constructor and this method will be removed along with SetupableStreamOperator . |
void |
setup(StreamTask<?,?> containingTask,
StreamConfig config,
Output<StreamRecord<OUT>> output)
Initializes the operator.
|
OperatorSnapshotFutures |
snapshotState(long checkpointId,
long timestamp,
CheckpointOptions checkpointOptions,
CheckpointStreamFactory factory)
Called to draw a state snapshot from the operator.
|
void |
snapshotState(StateSnapshotContext context)
Stream operators with state, which want to participate in a snapshot need to override this
hook method.
|
protected static final org.slf4j.Logger LOG
protected ChainingStrategy chainingStrategy
protected transient StreamConfig config
protected transient Output<StreamRecord<OUT>> output
protected transient OperatorMetricGroup metrics
protected transient LatencyStats latencyStats
protected transient ProcessingTimeService processingTimeService
public void setup(StreamTask<?,?> containingTask, StreamConfig config, Output<StreamRecord<OUT>> output)
SetupableStreamOperator
setup
in interface SetupableStreamOperator<OUT>
@Deprecated public void setProcessingTimeService(ProcessingTimeService processingTimeService)
ProcessingTimeService
instance should be passed by the operator
constructor and this method will be removed along with SetupableStreamOperator
.public MetricGroup getMetricGroup()
getMetricGroup
in interface StreamOperator<OUT>
public final void initializeState(StreamTaskStateInitializer streamTaskStateManager) throws Exception
StreamOperator
initializeState
in interface StreamOperator<OUT>
Exception
@Internal protected boolean isUsingCustomRawKeyedState()
snapshotState(StateSnapshotContext)
. If yes, subclasses
should override this method to return true
.
Subclasses need to explicitly indicate the use of raw keyed state because, internally, the
AbstractStreamOperator
may attempt to read from it as well to restore heap-based
timers and ultimately fail with read errors. By setting this flag to true
, this
allows the AbstractStreamOperator
to know that the data written in the raw keyed
states were not written by the timer services, and skips the timer restore attempt.
Please refer to FLINK-19741 for further details.
TODO: this method can be removed once all timers are moved to be managed by state backends.
snapshotState(StateSnapshotContext)
.public void open() throws Exception
The default implementation does nothing.
open
in interface StreamOperator<OUT>
Exception
- An exception in this method causes the operator to fail.public void close() throws Exception
OneInputStreamOperator.processElement(StreamRecord)
, or TwoInputStreamOperator.processElement1(StreamRecord)
and TwoInputStreamOperator.processElement2(StreamRecord)
.
The method is expected to flush all remaining buffered data. Exceptions during this flushing of buffered should be propagated, in order to cause the operation to be recognized asa failed, because the last data items are not processed properly.
close
in interface StreamOperator<OUT>
Exception
- An exception in this method causes the operator to fail.public void dispose() throws Exception
This method is expected to make a thorough effort to release all resources that the operator has acquired.
dispose
in interface StreamOperator<OUT>
dispose
in interface Disposable
Exception
- if something goes wrong during disposal.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>
checkpointId
- The ID of the checkpoint.Exception
- Throwing an exception here causes the operator to fail and go into
recovery.public final OperatorSnapshotFutures snapshotState(long checkpointId, long timestamp, CheckpointOptions checkpointOptions, CheckpointStreamFactory factory) throws Exception
StreamOperator
snapshotState
in interface StreamOperator<OUT>
Exception
- exception that happened during snapshotting.public void snapshotState(StateSnapshotContext context) throws Exception
snapshotState
in interface StreamOperatorStateHandler.CheckpointedStreamOperator
context
- context that provides information and means required for taking a snapshotException
public void initializeState(StateInitializationContext context) throws Exception
initializeState
in interface StreamOperatorStateHandler.CheckpointedStreamOperator
context
- context that allows to register different states.Exception
public void notifyCheckpointComplete(long checkpointId) throws Exception
CheckpointListener
Note that any exception during this method will not cause the checkpoint to fail any more.
notifyCheckpointComplete
in interface CheckpointListener
checkpointId
- The ID of the checkpoint that has been completed.Exception
- This method can propagate exceptions, which leads to a failure/recovery for
the task. Not that this will NOT lead to the checkpoint being revoked.public void notifyCheckpointAborted(long checkpointId) throws Exception
CheckpointListener
notifyCheckpointAborted
in interface CheckpointListener
checkpointId
- The ID of the checkpoint that has been aborted.Exception
- This method can propagate exceptions, which leads to a failure/recovery for
the task.public ExecutionConfig getExecutionConfig()
public StreamConfig getOperatorConfig()
public StreamTask<?,?> getContainingTask()
public ClassLoader getUserCodeClassloader()
protected String getOperatorName()
@VisibleForTesting public StreamingRuntimeContext getRuntimeContext()
@VisibleForTesting public <K> KeyedStateBackend<K> getKeyedStateBackend()
@VisibleForTesting public OperatorStateBackend getOperatorStateBackend()
@VisibleForTesting public ProcessingTimeService getProcessingTimeService()
ProcessingTimeService
responsible for getting the current processing time
and registering timers.protected <S extends State> S getPartitionedState(StateDescriptor<S,?> stateDescriptor) throws Exception
IllegalStateException
- Thrown, if the key/value state was already initialized.Exception
- Thrown, if the state backend cannot create the key/value state.protected <N,S extends State,T> S getOrCreateKeyedState(TypeSerializer<N> namespaceSerializer, StateDescriptor<S,T> stateDescriptor) throws Exception
Exception
protected <S extends State,N> S getPartitionedState(N namespace, TypeSerializer<N> namespaceSerializer, StateDescriptor<S,?> stateDescriptor) throws Exception
IllegalStateException
- Thrown, if the key/value state was already initialized.Exception
- Thrown, if the state backend cannot create the key/value state.public void setKeyContextElement1(StreamRecord record) throws Exception
setKeyContextElement1
in interface StreamOperator<OUT>
Exception
public void setKeyContextElement2(StreamRecord record) throws Exception
setKeyContextElement2
in interface StreamOperator<OUT>
Exception
public void setCurrentKey(Object key)
setCurrentKey
in interface KeyContext
public Object getCurrentKey()
getCurrentKey
in interface KeyContext
public KeyedStateStore getKeyedStateStore()
public final void setChainingStrategy(ChainingStrategy strategy)
setChainingStrategy
in interface SetupableStreamOperator<OUT>
public final ChainingStrategy getChainingStrategy()
getChainingStrategy
in interface SetupableStreamOperator<OUT>
public void processLatencyMarker(LatencyMarker latencyMarker) throws Exception
Exception
public void processLatencyMarker1(LatencyMarker latencyMarker) throws Exception
Exception
public void processLatencyMarker2(LatencyMarker latencyMarker) throws Exception
Exception
protected void reportOrForwardLatencyMarker(LatencyMarker marker)
public <K,N> InternalTimerService<N> getInternalTimerService(String name, TypeSerializer<N> namespaceSerializer, Triggerable<K,N> triggerable)
InternalTimerService
that can be used to query current processing time and
event time and to set timers. An operator can have several timer services, where each has its
own namespace serializer. Timer services are differentiated by the string key that is given
when requesting them, if you call this method with the same key multiple times you will get
the same timer service instance in subsequent requests.
Timers are always scoped to a key, the currently active key of a keyed stream operation. When a timer fires, this key will also be set as the currently active key.
Each timer has attached metadata, the namespace. Different timer services can have a
different namespace type. If you don't need namespace differentiation you can use VoidNamespaceSerializer
as the namespace serializer.
N
- The type of the timer namespace.name
- The name of the requested timer service. If no service exists under the given
name a new one will be created and returned.namespaceSerializer
- TypeSerializer
for the timer namespace.triggerable
- The Triggerable
that should be invoked when timers firepublic OperatorID getOperatorID()
getOperatorID
in interface StreamOperator<OUT>
@VisibleForTesting public int numProcessingTimeTimers()
@VisibleForTesting public int numEventTimeTimers()
protected Optional<InternalTimeServiceManager<?>> getTimeServiceManager()
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