org.apache.flink.runtime.operators

Class RegularPactTask<S extends Function,OT>

java.lang.Object

org.apache.flink.runtime.jobgraph.tasks.AbstractInvokable

org.apache.flink.runtime.operators.RegularPactTask<S,OT>

All Implemented Interfaces:

PactTaskContext<S,OT>

Direct Known Subclasses:

AbstractIterativePactTask

public class RegularPactTask<S extends Function,OT>
extends AbstractInvokable
implements PactTaskContext<S,OT>

The abstract base class for all tasks. Encapsulated common behavior and implements the main life-cycle of the user code.

Field Summary

Fields

Modifier and Type	Field and Description
protected MutableReader<?>[]	broadcastInputReaders The input readers for the configured broadcast variables for this task.
protected TypeSerializerFactory<?>[]	broadcastInputSerializers The serializers for the broadcast input data types.
protected ArrayList<ChainedDriver<?,?>>	chainedTasks A list of chained drivers, if there are any.
protected TaskConfig	config The task configuration with the setup parameters.
protected PactDriver<S,OT>	driver The driver that invokes the user code (the stub implementation).
protected List<BufferWriter>	eventualOutputs The output writers for the data that this task forwards to the next task.
protected TypeComparator<?>[]	inputComparators The comparators for the central driver.
protected MutableObjectIterator<?>[]	inputIterators The inputs reader, wrapped in an iterator.
protected MutableReader<?>[]	inputReaders The input readers to this task.
protected MutableObjectIterator<?>[]	inputs The inputs to the operator.
protected TypeSerializerFactory<?>[]	inputSerializers The serializers for the input data type.
protected int[]	iterativeBroadcastInputs The indices of the iterative broadcast inputs.
protected int[]	iterativeInputs The indices of the iterative inputs.
protected CloseableInputProvider<?>[]	localStrategies The local strategies that are applied on the inputs.
protected static org.slf4j.Logger	LOG
protected Collector<OT>	output The collector that forwards the user code's results.
protected SpillingResettableMutableObjectIterator<?>[]	resettableInputs The resettable inputs in the case where no temp barrier is needed.
protected boolean	running The flag that tags the task as still running.
protected DistributedRuntimeUDFContext	runtimeUdfContext The udf's runtime context.
protected S	stub The instantiated user code of this task's main operator (driver).
protected TempBarrier<?>[]	tempBarriers The optional temp barriers on the inputs for dead-lock breaking.

Constructor Summary

Constructors

Constructor and Description
RegularPactTask()

Method Summary

Methods

Modifier and Type	Method and Description
void	cancel() This method is called when a task is canceled either as a result of a user abort or an execution failure.
static void	cancelChainedTasks(List<ChainedDriver<?,?>> tasks) Cancels all tasks via their ChainedDriver.cancelTask() method.
static void	closeChainedTasks(List<ChainedDriver<?,?>> tasks, AbstractInvokable parent) Closes all chained tasks, in the order as they are stored in the array.
protected void	closeLocalStrategiesAndCaches()
static void	closeUserCode(Function stub) Closes the given stub using its RichFunction.close() method.
static String	constructLogString(String message, String taskName, AbstractInvokable parent) Utility function that composes a string for logging purposes.
protected MutableObjectIterator<?>	createInputIterator(MutableReader<?> inputReader, TypeSerializerFactory<?> serializerFactory)
DistributedRuntimeUDFContext	createRuntimeContext(String taskName)
protected void	excludeFromReset(int inputNum)
String	formatLogString(String message)
<X> TypeComparator<X>	getDriverComparator(int index)
<X> MutableObjectIterator<X>	getInput(int index)
<X> TypeSerializerFactory<X>	getInputSerializer(int index)
IOManager	getIOManager()
protected Collector<OT>	getLastOutputCollector()
TaskConfig	getLastTasksConfig()
MemoryManager	getMemoryManager()
protected int	getNumTaskInputs()
Collector<OT>	getOutputCollector()
static <T> Collector<T>	getOutputCollector(AbstractInvokable task, TaskConfig config, ClassLoader cl, List<BufferWriter> eventualOutputs, int numOutputs) Creates the Collector for the given task, as described by the given configuration.
AbstractInvokable	getOwningNepheleTask()
S	getStub()
TaskConfig	getTaskConfig()
protected void	initBroadcastInputReaders() Creates the record readers for the extra broadcast inputs as configured by TaskConfig.getNumBroadcastInputs().
protected void	initBroadcastInputsSerializers(int numBroadcastInputs) Creates all the serializers and iterators for the broadcast inputs.
protected void	initialize()
protected void	initInputReaders() Creates the record readers for the number of inputs as defined by getNumTaskInputs().
protected void	initInputsSerializersAndComparators(int numInputs, int numComparators) Creates all the serializers and comparators.
protected void	initLocalStrategies(int numInputs) NOTE: This method must be invoked after the invocation of #initInputReaders() and #initInputSerializersAndComparators(int)!
protected void	initOutputs() Creates a writer for each output.
static <T> Collector<T>	initOutputs(AbstractInvokable nepheleTask, ClassLoader cl, TaskConfig config, List<ChainedDriver<?,?>> chainedTasksTarget, List<BufferWriter> eventualOutputs) Creates a writer for each output.
static void	initOutputWriters(List<BufferWriter> writers)
protected S	initStub(Class<? super S> stubSuperClass)
static <T> T	instantiateUserCode(TaskConfig config, ClassLoader cl, Class<? super T> superClass) Instantiates a user code class from is definition in the task configuration.
void	invoke() The main work method.
static void	logAndThrowException(Exception ex, AbstractInvokable parent) Prints an error message and throws the given exception.
static void	openChainedTasks(List<ChainedDriver<?,?>> tasks, AbstractInvokable parent) Opens all chained tasks, in the order as they are stored in the array.
static void	openUserCode(Function stub, Configuration parameters) Opens the given stub using its RichFunction.open(Configuration) method.
protected <X> void	readAndSetBroadcastInput(int inputNum, String bcVarName, DistributedRuntimeUDFContext context, int superstep)
void	registerInputOutput() Initialization method.
protected void	releaseBroadcastVariables(String bcVarName, int superstep, DistributedRuntimeUDFContext context)
protected static void	reportAndClearAccumulators(Environment env, Map<String,Accumulator<?,?>> accumulators, ArrayList<ChainedDriver<?,?>> chainedTasks) This method is called at the end of a task, receiving the accumulators of the task and the chained tasks.
protected void	resetAllInputs()
protected void	run()
protected void	setLastOutputCollector(Collector<OT> newOutputCollector) Sets the last output Collector of the collector chain of this RegularPactTask.

Methods inherited from class org.apache.flink.runtime.jobgraph.tasks.AbstractInvokable

getCurrentNumberOfSubtasks, getEnvironment, getIndexInSubtaskGroup, getJobConfiguration, getTaskConfiguration, getUserCodeClassLoader, setEnvironment

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.flink.runtime.operators.PactTaskContext

getUserCodeClassLoader

Field Detail

LOG

protected static final org.slf4j.Logger LOG

driver

protected volatile PactDriver<S extends Function,OT> driver

The driver that invokes the user code (the stub implementation). The central driver in this task (further drivers may be chained behind this driver).

stub

protected S extends Function stub

The instantiated user code of this task's main operator (driver). May be null if the operator has no udf.

runtimeUdfContext

protected DistributedRuntimeUDFContext runtimeUdfContext

The udf's runtime context.

output

protected Collector<OT> output

The collector that forwards the user code's results. May forward to a channel or to chained drivers within this task.

eventualOutputs

protected List<BufferWriter> eventualOutputs

The output writers for the data that this task forwards to the next task. The latest driver (the central, if no chained drivers exist, otherwise the last chained driver) produces its output to these writers.

inputReaders

protected MutableReader<?>[] inputReaders

The input readers to this task.

broadcastInputReaders

protected MutableReader<?>[] broadcastInputReaders

The input readers for the configured broadcast variables for this task.

inputIterators

protected MutableObjectIterator<?>[] inputIterators

The inputs reader, wrapped in an iterator. Prior to the local strategies, etc...

iterativeInputs

protected int[] iterativeInputs

The indices of the iterative inputs. Empty, if the task is not iterative.

iterativeBroadcastInputs

protected int[] iterativeBroadcastInputs

The indices of the iterative broadcast inputs. Empty, if non of the inputs is iteratve.

localStrategies

protected volatile CloseableInputProvider<?>[] localStrategies

The local strategies that are applied on the inputs.

tempBarriers

protected volatile TempBarrier<?>[] tempBarriers

The optional temp barriers on the inputs for dead-lock breaking. Are optionally resettable.

resettableInputs

protected volatile SpillingResettableMutableObjectIterator<?>[] resettableInputs

The resettable inputs in the case where no temp barrier is needed.

inputs

protected MutableObjectIterator<?>[] inputs

The inputs to the operator. Return the readers' data after the application of the local strategy and the temp-table barrier.

inputSerializers

protected TypeSerializerFactory<?>[] inputSerializers

The serializers for the input data type.

broadcastInputSerializers

protected TypeSerializerFactory<?>[] broadcastInputSerializers

The serializers for the broadcast input data types.

inputComparators

protected TypeComparator<?>[] inputComparators

The comparators for the central driver.

config

protected TaskConfig config

The task configuration with the setup parameters.

chainedTasks

protected ArrayList<ChainedDriver<?,?>> chainedTasks

A list of chained drivers, if there are any.

running

protected volatile boolean running

The flag that tags the task as still running. Checked periodically to abort processing.

Constructor Detail

RegularPactTask

public RegularPactTask()

Method Detail

registerInputOutput

public void registerInputOutput()

Initialization method. Runs in the execution graph setup phase in the JobManager and as a setup method on the TaskManager.

Specified by:

registerInputOutput in class AbstractInvokable

invoke

public void invoke()
            throws Exception

The main work method.

Specified by:

invoke in class AbstractInvokable

Throws:

Exception - thrown if any exception occurs during the execution of the tasks

cancel

public void cancel()
            throws Exception

Description copied from class: AbstractInvokable

This method is called when a task is canceled either as a result of a user abort or an execution failure. It can be overwritten to respond to shut down the user code properly.

Overrides:

cancel in class AbstractInvokable

Throws:

Exception - thrown if any exception occurs during the execution of the user code

initialize

protected void initialize()
                   throws Exception

Throws:

Exception

readAndSetBroadcastInput

protected <X> void readAndSetBroadcastInput(int inputNum,
                                String bcVarName,
                                DistributedRuntimeUDFContext context,
                                int superstep)
                                 throws IOException

Throws:

IOException

releaseBroadcastVariables

protected void releaseBroadcastVariables(String bcVarName,
                             int superstep,
                             DistributedRuntimeUDFContext context)

run

protected void run()
            throws Exception

Throws:

Exception

reportAndClearAccumulators

protected static void reportAndClearAccumulators(Environment env,
                              Map<String,Accumulator<?,?>> accumulators,
                              ArrayList<ChainedDriver<?,?>> chainedTasks)

This method is called at the end of a task, receiving the accumulators of the task and the chained tasks. It merges them into a single map of accumulators and sends them to the JobManager.

Parameters:

chainedTasks - Each chained task might have accumulators which will be merged with the accumulators of the stub.

closeLocalStrategiesAndCaches

protected void closeLocalStrategiesAndCaches()

getLastOutputCollector

protected Collector<OT> getLastOutputCollector()

Returns:

the last output collector in the collector chain

setLastOutputCollector

protected void setLastOutputCollector(Collector<OT> newOutputCollector)

Sets the last output Collector of the collector chain of this RegularPactTask.

In case of chained tasks, the output collector of the last ChainedDriver is set. Otherwise it is the single collector of the RegularPactTask.

Parameters:

newOutputCollector - new output collector to set as last collector

getLastTasksConfig

public TaskConfig getLastTasksConfig()

initStub

protected S initStub(Class<? super S> stubSuperClass)
                               throws Exception

Throws:

Exception

initInputReaders

protected void initInputReaders()
                         throws Exception

Creates the record readers for the number of inputs as defined by getNumTaskInputs(). This method requires that the task configuration, the driver, and the user-code class loader are set.

Throws:

Exception

initBroadcastInputReaders

protected void initBroadcastInputReaders()
                                  throws Exception

Creates the record readers for the extra broadcast inputs as configured by TaskConfig.getNumBroadcastInputs(). This method requires that the task configuration, the driver, and the user-code class loader are set.

Throws:

Exception

initInputsSerializersAndComparators

protected void initInputsSerializersAndComparators(int numInputs,
                                       int numComparators)
                                            throws Exception

Creates all the serializers and comparators.

Throws:

Exception

initBroadcastInputsSerializers

protected void initBroadcastInputsSerializers(int numBroadcastInputs)
                                       throws Exception

Creates all the serializers and iterators for the broadcast inputs.

Throws:

Exception

initLocalStrategies

protected void initLocalStrategies(int numInputs)
                            throws Exception

NOTE: This method must be invoked after the invocation of #initInputReaders() and #initInputSerializersAndComparators(int)!

Parameters:

numInputs -

Throws:

Exception

resetAllInputs

protected void resetAllInputs()
                       throws Exception

Throws:

Exception

excludeFromReset

protected void excludeFromReset(int inputNum)

createInputIterator

protected MutableObjectIterator<?> createInputIterator(MutableReader<?> inputReader,
                                           TypeSerializerFactory<?> serializerFactory)

getNumTaskInputs

protected int getNumTaskInputs()

initOutputs

protected void initOutputs()
                    throws Exception

Creates a writer for each output. Creates an OutputCollector which forwards its input to all writers. The output collector applies the configured shipping strategies for each writer.

Throws:

Exception

createRuntimeContext

public DistributedRuntimeUDFContext createRuntimeContext(String taskName)

getTaskConfig

public TaskConfig getTaskConfig()

Specified by:

getTaskConfig in interface PactTaskContext<S extends Function,OT>

getMemoryManager

public MemoryManager getMemoryManager()

Specified by:

getMemoryManager in interface PactTaskContext<S extends Function,OT>

getIOManager

public IOManager getIOManager()

Specified by:

getIOManager in interface PactTaskContext<S extends Function,OT>

getStub

public S getStub()

Specified by:

getStub in interface PactTaskContext<S extends Function,OT>

getOutputCollector

public Collector<OT> getOutputCollector()

Specified by:

getOutputCollector in interface PactTaskContext<S extends Function,OT>

getOwningNepheleTask

public AbstractInvokable getOwningNepheleTask()

Specified by:

getOwningNepheleTask in interface PactTaskContext<S extends Function,OT>

formatLogString

public String formatLogString(String message)

Specified by:

formatLogString in interface PactTaskContext<S extends Function,OT>

getInput

public <X> MutableObjectIterator<X> getInput(int index)

Specified by:

getInput in interface PactTaskContext<S extends Function,OT>

getInputSerializer

public <X> TypeSerializerFactory<X> getInputSerializer(int index)

Specified by:

getInputSerializer in interface PactTaskContext<S extends Function,OT>

getDriverComparator

public <X> TypeComparator<X> getDriverComparator(int index)

Specified by:

getDriverComparator in interface PactTaskContext<S extends Function,OT>

constructLogString

public static String constructLogString(String message,
                        String taskName,
                        AbstractInvokable parent)

Utility function that composes a string for logging purposes. The string includes the given message, the given name of the task and the index in its subtask group as well as the number of instances that exist in its subtask group.

Parameters:

message - The main message for the log.

taskName - The name of the task.

parent - The nephele task that contains the code producing the message.

Returns:

The string for logging.

logAndThrowException

public static void logAndThrowException(Exception ex,
                        AbstractInvokable parent)
                                 throws Exception

Prints an error message and throws the given exception. If the exception is of the type ExceptionInChainedStubException then the chain of contained exceptions is followed until an exception of a different type is found.

Parameters:

ex - The exception to be thrown.

parent - The parent task, whose information is included in the log message.

Throws:

Exception - Always thrown.

getOutputCollector

public static <T> Collector<T> getOutputCollector(AbstractInvokable task,
                                  TaskConfig config,
                                  ClassLoader cl,
                                  List<BufferWriter> eventualOutputs,
                                  int numOutputs)
                                       throws Exception

Creates the Collector for the given task, as described by the given configuration. The output collector contains the writers that forward the data to the different tasks that the given task is connected to. Each writer applies a the partitioning as described in the configuration.

Parameters:

task - The task that the output collector is created for.

config - The configuration describing the output shipping strategies.

cl - The classloader used to load user defined types.

numOutputs - The number of outputs described in the configuration.

Returns:

The OutputCollector that data produced in this task is submitted to.

Throws:

Exception

initOutputs

public static <T> Collector<T> initOutputs(AbstractInvokable nepheleTask,
                           ClassLoader cl,
                           TaskConfig config,
                           List<ChainedDriver<?,?>> chainedTasksTarget,
                           List<BufferWriter> eventualOutputs)
                                throws Exception

Creates a writer for each output. Creates an OutputCollector which forwards its input to all writers. The output collector applies the configured shipping strategy.

Throws:

Exception

initOutputWriters

public static void initOutputWriters(List<BufferWriter> writers)

openUserCode

public static void openUserCode(Function stub,
                Configuration parameters)
                         throws Exception

Opens the given stub using its RichFunction.open(Configuration) method. If the open call produces an exception, a new exception with a standard error message is created, using the encountered exception as its cause.

Parameters:

stub - The user code instance to be opened.

parameters - The parameters supplied to the user code.

Throws:

Exception - Thrown, if the user code's open method produces an exception.

closeUserCode

public static void closeUserCode(Function stub)
                          throws Exception

Closes the given stub using its RichFunction.close() method. If the close call produces an exception, a new exception with a standard error message is created, using the encountered exception as its cause.

Parameters:

stub - The user code instance to be closed.

Throws:

Exception - Thrown, if the user code's close method produces an exception.

openChainedTasks

public static void openChainedTasks(List<ChainedDriver<?,?>> tasks,
                    AbstractInvokable parent)
                             throws Exception

Opens all chained tasks, in the order as they are stored in the array. The opening process creates a standardized log info message.

Parameters:

tasks - The tasks to be opened.

parent - The parent task, used to obtain parameters to include in the log message.

Throws:

Exception - Thrown, if the opening encounters an exception.

closeChainedTasks

public static void closeChainedTasks(List<ChainedDriver<?,?>> tasks,
                     AbstractInvokable parent)
                              throws Exception

Closes all chained tasks, in the order as they are stored in the array. The closing process creates a standardized log info message.

Parameters:

tasks - The tasks to be closed.

parent - The parent task, used to obtain parameters to include in the log message.

Throws:

Exception - Thrown, if the closing encounters an exception.

cancelChainedTasks

public static void cancelChainedTasks(List<ChainedDriver<?,?>> tasks)

Cancels all tasks via their ChainedDriver.cancelTask() method. Any occurring exception and error is suppressed, such that the canceling method of every task is invoked in all cases.

Parameters:

tasks - The tasks to be canceled.

instantiateUserCode

public static <T> T instantiateUserCode(TaskConfig config,
                        ClassLoader cl,
                        Class<? super T> superClass)

Instantiates a user code class from is definition in the task configuration. The class is instantiated without arguments using the null-ary constructor. Instantiation will fail if this constructor does not exist or is not public.

Type Parameters:

T - The generic type of the user code class.

Parameters:

config - The task configuration containing the class description.

cl - The class loader to be used to load the class.

superClass - The super class that the user code class extends or implements, for type checking.

Returns:

An instance of the user code class.