Package org.apache.flink.streaming.runtime.tasks

This package contains classes that realize streaming tasks.

See: Description

Interface Summary

Interface	Description
AsyncExceptionHandler	An interface marking a task as capable of handling exceptions thrown by different threads, other than the one executing the task itself.
OperatorChain.WatermarkGaugeExposingOutput<T>	An Output that measures the last emitted watermark with a WatermarkGauge.
ProcessingTimeCallback	Interface for processing-time callbacks that can be registered at a ProcessingTimeService.
ProcessingTimeService	Defines the current processing time and handles all related actions, such as register timers for tasks to be executed in the future.
StreamTaskActionExecutor	Executes Runnable, ThrowingRunnable, or Callable.
TimerService	A common timer service interface with life cycle methods.

Class Summary

Class	Description
AbstractTwoInputStreamTask<IN1,IN2,OUT>	Abstract class for executing a TwoInputStreamOperator.
OneInputStreamTask<IN,OUT>	A StreamTask for executing a OneInputStreamOperator.
OperatorChain<OUT,OP extends StreamOperator<OUT>>	The OperatorChain contains all operators that are executed as one chain within a single StreamTask.
SourceReaderStreamTask<T>	A subclass of StreamTask for executing the SourceReaderOperator.
SourceStreamTask<OUT,SRC extends SourceFunction<OUT>,OP extends StreamSource<OUT,SRC>>	StreamTask for executing a StreamSource.
StreamIterationHead<OUT>	A special StreamTask that is used for executing feedback edges.
StreamIterationTail<IN>	A special StreamTask that is used for executing feedback edges.
StreamTask<OUT,OP extends StreamOperator<OUT>>	Base class for all streaming tasks.
StreamTask.AsyncCheckpointRunnable	This runnable executes the asynchronous parts of all involved backend snapshots for the subtask.
StreamTaskActionExecutor.SynchronizedStreamTaskActionExecutor	Deprecated this class should only be used in SourceStreamTask which exposes the checkpoint lock as part of Public API.
SystemProcessingTimeService	A TimerService which assigns as current processing time the result of calling System.currentTimeMillis() and registers timers using a ScheduledThreadPoolExecutor.
TestProcessingTimeService	This is a TimerService and ProcessingTimeService used strictly for testing the processing time functionality.
TwoInputStreamTask<IN1,IN2,OUT>	A StreamTask for executing a TwoInputStreamOperator and supporting the TwoInputStreamOperator to select input for reading.

Exception Summary

Exception	Description
AsynchronousException	An exception for wrapping exceptions that are thrown by an operator in threads other than the main compute thread of that operator.
ExceptionInChainedOperatorException	A special exception that signifies that the cause exception came from a chained operator.
StreamTaskException	An exception that is thrown by the stream vertices when encountering an illegal condition.
TimerException	RuntimeException for wrapping exceptions that are thrown in the timer callback of the timer service in StreamTask.

Package org.apache.flink.streaming.runtime.tasks Description

This package contains classes that realize streaming tasks. These tasks are executable stream consumers and producers that are scheduled by the distributed dataflow runtime. Each task occupies one execution slot and is run with by an executing thread.

The tasks merely set up the distributed stream coordination and the checkpointing. Internally, the tasks create one or more operators, perform the stream transformations.