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/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.flink.runtime.operators;

import org.apache.flink.api.common.ExecutionConfig;
import org.apache.flink.api.common.accumulators.Accumulator;
import org.apache.flink.api.common.distributions.DataDistribution;
import org.apache.flink.api.common.functions.Function;
import org.apache.flink.api.common.functions.GroupCombineFunction;
import org.apache.flink.api.common.functions.Partitioner;
import org.apache.flink.api.common.functions.util.FunctionUtils;
import org.apache.flink.api.common.typeutils.TypeComparator;
import org.apache.flink.api.common.typeutils.TypeComparatorFactory;
import org.apache.flink.api.common.typeutils.TypeSerializerFactory;
import org.apache.flink.configuration.Configuration;
import org.apache.flink.core.io.IOReadableWritable;
import org.apache.flink.metrics.MetricGroup;
import org.apache.flink.runtime.broadcast.BroadcastVariableMaterialization;
import org.apache.flink.runtime.execution.CancelTaskException;
import org.apache.flink.runtime.execution.Environment;
import org.apache.flink.runtime.io.disk.iomanager.IOManager;
import org.apache.flink.runtime.io.network.api.reader.MutableReader;
import org.apache.flink.runtime.io.network.api.reader.MutableRecordReader;
import org.apache.flink.runtime.io.network.api.writer.ChannelSelector;
import org.apache.flink.runtime.io.network.api.writer.RecordWriter;
import org.apache.flink.runtime.io.network.api.writer.RecordWriterBuilder;
import org.apache.flink.runtime.io.network.partition.consumer.InputGate;
import org.apache.flink.runtime.io.network.partition.consumer.UnionInputGate;
import org.apache.flink.runtime.jobgraph.tasks.AbstractInvokable;
import org.apache.flink.runtime.memory.MemoryManager;
import org.apache.flink.runtime.metrics.groups.OperatorMetricGroup;
import org.apache.flink.runtime.operators.chaining.ChainedDriver;
import org.apache.flink.runtime.operators.chaining.ExceptionInChainedStubException;
import org.apache.flink.runtime.operators.resettable.SpillingResettableMutableObjectIterator;
import org.apache.flink.runtime.operators.shipping.OutputCollector;
import org.apache.flink.runtime.operators.shipping.OutputEmitter;
import org.apache.flink.runtime.operators.shipping.ShipStrategyType;
import org.apache.flink.runtime.operators.sort.CombiningUnilateralSortMerger;
import org.apache.flink.runtime.operators.sort.UnilateralSortMerger;
import org.apache.flink.runtime.operators.util.CloseableInputProvider;
import org.apache.flink.runtime.operators.util.DistributedRuntimeUDFContext;
import org.apache.flink.runtime.operators.util.LocalStrategy;
import org.apache.flink.runtime.operators.util.ReaderIterator;
import org.apache.flink.runtime.operators.util.TaskConfig;
import org.apache.flink.runtime.plugable.DeserializationDelegate;
import org.apache.flink.runtime.plugable.SerializationDelegate;
import org.apache.flink.runtime.taskmanager.TaskManagerRuntimeInfo;
import org.apache.flink.util.Collector;
import org.apache.flink.util.InstantiationUtil;
import org.apache.flink.util.MutableObjectIterator;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;

/**
 * The base class for all batch tasks. Encapsulated common behavior and implements the main life-cycle
 * of the user code.
 */
public class BatchTask extends AbstractInvokable implements TaskContext {

	protected static final Logger LOG = LoggerFactory.getLogger(BatchTask.class);

	// --------------------------------------------------------------------------------------------

	/**
	 * The driver that invokes the user code (the stub implementation). The central driver in this task
	 * (further drivers may be chained behind this driver).
	 */
	protected volatile Driver driver;

	/**
	 * The instantiated user code of this task's main operator (driver). May be null if the operator has no udf.
	 */
	protected S stub;

	/**
	 * The udf's runtime context.
	 */
	protected DistributedRuntimeUDFContext runtimeUdfContext;

	/**
	 * The collector that forwards the user code's results. May forward to a channel or to chained drivers within
	 * this task.
	 */
	protected Collector output;

	/**
	 * 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.
	 */
	protected List> eventualOutputs;

	/**
	 * The input readers of this task.
	 */
	protected MutableReader[] inputReaders;

	/**
	 * The input readers for the configured broadcast variables for this task.
	 */
	protected MutableReader[] broadcastInputReaders;
	
	/**
	 * The inputs reader, wrapped in an iterator. Prior to the local strategies, etc...
	 */
	protected MutableObjectIterator[] inputIterators;

	/**
	 * The indices of the iterative inputs. Empty, if the task is not iterative. 
	 */
	protected int[] iterativeInputs;
	
	/**
	 * The indices of the iterative broadcast inputs. Empty, if non of the inputs is iterative.
	 */
	protected int[] iterativeBroadcastInputs;
	
	/**
	 * The local strategies that are applied on the inputs.
	 */
	protected volatile CloseableInputProvider[] localStrategies;

	/**
	 * The optional temp barriers on the inputs for dead-lock breaking. Are
	 * optionally resettable.
	 */
	protected volatile TempBarrier[] tempBarriers;

	/**
	 * The resettable inputs in the case where no temp barrier is needed.
	 */
	protected volatile SpillingResettableMutableObjectIterator[] resettableInputs;

	/**
	 * The inputs to the operator. Return the readers' data after the application of the local strategy
	 * and the temp-table barrier.
	 */
	protected MutableObjectIterator[] inputs;

	/**
	 * The serializers for the input data type.
	 */
	protected TypeSerializerFactory[] inputSerializers;

	/**
	 * The serializers for the broadcast input data types.
	 */
	protected TypeSerializerFactory[] broadcastInputSerializers;

	/**
	 * The comparators for the central driver.
	 */
	protected TypeComparator[] inputComparators;

	/**
	 * The task configuration with the setup parameters.
	 */
	protected TaskConfig config;

	/**
	 * A list of chained drivers, if there are any.
	 */
	protected ArrayList> chainedTasks;

	/**
	 * Certain inputs may be excluded from resetting. For example, the initial partial solution
	 * in an iteration head must not be reset (it is read through the back channel), when all
	 * others are reset.
	 */
	private boolean[] excludeFromReset;

	/**
	 * Flag indicating for each input whether it is cached and can be reset.
	 */
	private boolean[] inputIsCached;

	/**
	 * flag indicating for each input whether it must be asynchronously materialized.
	 */
	private boolean[] inputIsAsyncMaterialized;

	/**
	 * The amount of memory per input that is dedicated to the materialization.
	 */
	private int[] materializationMemory;

	/**
	 * The flag that tags the task as still running. Checked periodically to abort processing.
	 */
	protected volatile boolean running = true;

	/**
	 * The accumulator map used in the RuntimeContext.
	 */
	protected Map> accumulatorMap;
	private OperatorMetricGroup metrics;

	// --------------------------------------------------------------------------------------------
	//                                  Constructor
	// --------------------------------------------------------------------------------------------

	/**
	 * Create an Invokable task and set its environment.
	 *
	 * @param environment The environment assigned to this invokable.
	 */
	public BatchTask(Environment environment) {
		super(environment);
	}

	// --------------------------------------------------------------------------------------------
	//                                  Task Interface
	// --------------------------------------------------------------------------------------------

	/**
	 * The main work method.
	 */
	@Override
	public void invoke() throws Exception {
		// --------------------------------------------------------------------
		// Initialize
		// --------------------------------------------------------------------
		if (LOG.isDebugEnabled()) {
			LOG.debug(formatLogString("Start registering input and output."));
		}

		// obtain task configuration (including stub parameters)
		Configuration taskConf = getTaskConfiguration();
		this.config = new TaskConfig(taskConf);

		// now get the operator class which drives the operation
		final Class> driverClass = this.config.getDriver();
		this.driver = InstantiationUtil.instantiate(driverClass, Driver.class);

		String headName =  getEnvironment().getTaskInfo().getTaskName().split("->")[0].trim();
		this.metrics = getEnvironment().getMetricGroup()
			.getOrAddOperator(headName.startsWith("CHAIN") ? headName.substring(6) : headName);
		this.metrics.getIOMetricGroup().reuseInputMetricsForTask();
		if (config.getNumberOfChainedStubs() == 0) {
			this.metrics.getIOMetricGroup().reuseOutputMetricsForTask();
		}

		// initialize the readers.
		// this does not yet trigger any stream consuming or processing.
		initInputReaders();
		initBroadcastInputReaders();

		// initialize the writers.
		initOutputs();

		if (LOG.isDebugEnabled()) {
			LOG.debug(formatLogString("Finished registering input and output."));
		}

		// --------------------------------------------------------------------
		// Invoke
		// --------------------------------------------------------------------
		if (LOG.isDebugEnabled()) {
			LOG.debug(formatLogString("Start task code."));
		}

		this.runtimeUdfContext = createRuntimeContext(metrics);

		// whatever happens in this scope, make sure that the local strategies are cleaned up!
		// note that the initialization of the local strategies is in the try-finally block as well,
		// so that the thread that creates them catches its own errors that may happen in that process.
		// this is especially important, since there may be asynchronous closes (such as through canceling).
		try {
			// initialize the remaining data structures on the input and trigger the local processing
			// the local processing includes building the dams / caches
			try {
				int numInputs = driver.getNumberOfInputs();
				int numComparators = driver.getNumberOfDriverComparators();
				int numBroadcastInputs = this.config.getNumBroadcastInputs();
				
				initInputsSerializersAndComparators(numInputs, numComparators);
				initBroadcastInputsSerializers(numBroadcastInputs);
				
				// set the iterative status for inputs and broadcast inputs
				{
					List iterativeInputs = new ArrayList();
					
					for (int i = 0; i < numInputs; i++) {
						final int numberOfEventsUntilInterrupt = getTaskConfig().getNumberOfEventsUntilInterruptInIterativeGate(i);
			
						if (numberOfEventsUntilInterrupt < 0) {
							throw new IllegalArgumentException();
						}
						else if (numberOfEventsUntilInterrupt > 0) {
							this.inputReaders[i].setIterativeReader();
							iterativeInputs.add(i);
				
							if (LOG.isDebugEnabled()) {
								LOG.debug(formatLogString("Input [" + i + "] reads in supersteps with [" +
										+ numberOfEventsUntilInterrupt + "] event(s) till next superstep."));
							}
						}
					}
					this.iterativeInputs = asArray(iterativeInputs);
				}
				
				{
					List iterativeBcInputs = new ArrayList();
					
					for (int i = 0; i < numBroadcastInputs; i++) {
						final int numberOfEventsUntilInterrupt = getTaskConfig().getNumberOfEventsUntilInterruptInIterativeBroadcastGate(i);
						
						if (numberOfEventsUntilInterrupt < 0) {
							throw new IllegalArgumentException();
						}
						else if (numberOfEventsUntilInterrupt > 0) {
							this.broadcastInputReaders[i].setIterativeReader();
							iterativeBcInputs.add(i);
				
							if (LOG.isDebugEnabled()) {
								LOG.debug(formatLogString("Broadcast input [" + i + "] reads in supersteps with [" +
										+ numberOfEventsUntilInterrupt + "] event(s) till next superstep."));
							}
						}
					}
					this.iterativeBroadcastInputs = asArray(iterativeBcInputs);
				}
				
				initLocalStrategies(numInputs);
			}
			catch (Exception e) {
				throw new RuntimeException("Initializing the input processing failed" +
						(e.getMessage() == null ? "." : ": " + e.getMessage()), e);
			}

			if (!this.running) {
				if (LOG.isDebugEnabled()) {
					LOG.debug(formatLogString("Task cancelled before task code was started."));
				}
				return;
			}

			// pre main-function initialization
			initialize();

			// read the broadcast variables. they will be released in the finally clause 
			for (int i = 0; i < this.config.getNumBroadcastInputs(); i++) {
				final String name = this.config.getBroadcastInputName(i);
				readAndSetBroadcastInput(i, name, this.runtimeUdfContext, 1 /* superstep one for the start */);
			}

			// the work goes here
			run();
		}
		finally {
			// clean up in any case!
			closeLocalStrategiesAndCaches();

			clearReaders(inputReaders);
			clearWriters(eventualOutputs);

		}

		if (this.running) {
			if (LOG.isDebugEnabled()) {
				LOG.debug(formatLogString("Finished task code."));
			}
		} else {
			if (LOG.isDebugEnabled()) {
				LOG.debug(formatLogString("Task code cancelled."));
			}
		}
	}

	@Override
	public void cancel() throws Exception {
		this.running = false;

		if (LOG.isDebugEnabled()) {
			LOG.debug(formatLogString("Cancelling task code"));
		}

		try {
			if (this.driver != null) {
				this.driver.cancel();
			}
		} finally {
			closeLocalStrategiesAndCaches();
		}
	}

	// --------------------------------------------------------------------------------------------
	//                                  Main Work Methods
	// --------------------------------------------------------------------------------------------

	protected void initialize() throws Exception {
		// create the operator
		try {
			this.driver.setup(this);
		}
		catch (Throwable t) {
			throw new Exception("The driver setup for '" + this.getEnvironment().getTaskInfo().getTaskName() +
				"' , caused an error: " + t.getMessage(), t);
		}
		
		// instantiate the UDF
		try {
			final Class userCodeFunctionType = this.driver.getStubType();
			// if the class is null, the driver has no user code
			if (userCodeFunctionType != null) {
				this.stub = initStub(userCodeFunctionType);
			}
		} catch (Exception e) {
			throw new RuntimeException("Initializing the UDF" +
					(e.getMessage() == null ? "." : ": " + e.getMessage()), e);
		}
	}
	
	protected  void readAndSetBroadcastInput(int inputNum, String bcVarName, DistributedRuntimeUDFContext context, int superstep) throws IOException {
		
		if (LOG.isDebugEnabled()) {
			LOG.debug(formatLogString("Setting broadcast variable '" + bcVarName + "'" + 
				(superstep > 1 ? ", superstep " + superstep : "")));
		}
		
		@SuppressWarnings("unchecked")
		final TypeSerializerFactory serializerFactory =  (TypeSerializerFactory) this.broadcastInputSerializers[inputNum];
		
		final MutableReader reader = this.broadcastInputReaders[inputNum];

		BroadcastVariableMaterialization variable = getEnvironment().getBroadcastVariableManager().materializeBroadcastVariable(bcVarName, superstep, this, reader, serializerFactory);
		context.setBroadcastVariable(bcVarName, variable);
	}
	
	protected void releaseBroadcastVariables(String bcVarName, int superstep, DistributedRuntimeUDFContext context) {
		if (LOG.isDebugEnabled()) {
			LOG.debug(formatLogString("Releasing broadcast variable '" + bcVarName + "'" + 
				(superstep > 1 ? ", superstep " + superstep : "")));
		}
		
		getEnvironment().getBroadcastVariableManager().releaseReference(bcVarName, superstep, this);
		context.clearBroadcastVariable(bcVarName);
	}
	

	protected void run() throws Exception {
		// ---------------------------- Now, the actual processing starts ------------------------
		// check for asynchronous canceling
		if (!this.running) {
			return;
		}

		boolean stubOpen = false;

		try {
			// run the data preparation
			try {
				this.driver.prepare();
			}
			catch (Throwable t) {
				// if the preparation caused an error, clean up
				// errors during clean-up are swallowed, because we have already a root exception
				throw new Exception("The data preparation for task '" + this.getEnvironment().getTaskInfo().getTaskName() +
					"' , caused an error: " + t.getMessage(), t);
			}

			// check for canceling
			if (!this.running) {
				return;
			}

			// start all chained tasks
			BatchTask.openChainedTasks(this.chainedTasks, this);

			// open stub implementation
			if (this.stub != null) {
				try {
					Configuration stubConfig = this.config.getStubParameters();
					FunctionUtils.openFunction(this.stub, stubConfig);
					stubOpen = true;
				}
				catch (Throwable t) {
					throw new Exception("The user defined 'open()' method caused an exception: " + t.getMessage(), t);
				}
			}

			// run the user code
			this.driver.run();

			// close. We close here such that a regular close throwing an exception marks a task as failed.
			if (this.running && this.stub != null) {
				FunctionUtils.closeFunction(this.stub);
				stubOpen = false;
			}

			// close all chained tasks letting them report failure
			BatchTask.closeChainedTasks(this.chainedTasks, this);

			// close the output collector
			this.output.close();
		}
		catch (Exception ex) {
			// close the input, but do not report any exceptions, since we already have another root cause
			if (stubOpen) {
				try {
					FunctionUtils.closeFunction(this.stub);
				}
				catch (Throwable t) {
					// do nothing
				}
			}
			
			// if resettable driver invoke teardown
			if (this.driver instanceof ResettableDriver) {
				final ResettableDriver resDriver = (ResettableDriver) this.driver;
				try {
					resDriver.teardown();
				} catch (Throwable t) {
					throw new Exception("Error while shutting down an iterative operator: " + t.getMessage(), t);
				}
			}

			BatchTask.cancelChainedTasks(this.chainedTasks);

			ex = ExceptionInChainedStubException.exceptionUnwrap(ex);

			if (ex instanceof CancelTaskException) {
				// forward canceling exception
				throw ex;
			}
			else if (this.running) {
				// throw only if task was not cancelled. in the case of canceling, exceptions are expected 
				BatchTask.logAndThrowException(ex, this);
			}
		}
		finally {
			this.driver.cleanup();
		}
	}

	protected void closeLocalStrategiesAndCaches() {
		
		// make sure that all broadcast variable references held by this task are released
		if (LOG.isDebugEnabled()) {
			LOG.debug(formatLogString("Releasing all broadcast variables."));
		}
		
		getEnvironment().getBroadcastVariableManager().releaseAllReferencesFromTask(this);
		if (runtimeUdfContext != null) {
			runtimeUdfContext.clearAllBroadcastVariables();
		}
		
		// clean all local strategies and caches/pipeline breakers. 
		
		if (this.localStrategies != null) {
			for (int i = 0; i < this.localStrategies.length; i++) {
				if (this.localStrategies[i] != null) {
					try {
						this.localStrategies[i].close();
					} catch (Throwable t) {
						LOG.error("Error closing local strategy for input " + i, t);
					}
				}
			}
		}
		if (this.tempBarriers != null) {
			for (int i = 0; i < this.tempBarriers.length; i++) {
				if (this.tempBarriers[i] != null) {
					try {
						this.tempBarriers[i].close();
					} catch (Throwable t) {
						LOG.error("Error closing temp barrier for input " + i, t);
					}
				}
			}
		}
		if (this.resettableInputs != null) {
			for (int i = 0; i < this.resettableInputs.length; i++) {
				if (this.resettableInputs[i] != null) {
					try {
						this.resettableInputs[i].close();
					} catch (Throwable t) {
						LOG.error("Error closing cache for input " + i, t);
					}
				}
			}
		}
	}

	// --------------------------------------------------------------------------------------------
	//                                 Task Setup and Teardown
	// --------------------------------------------------------------------------------------------

	/**
	 * @return the last output collector in the collector chain
	 */
	@SuppressWarnings("unchecked")
	protected Collector getLastOutputCollector() {
		int numChained = this.chainedTasks.size();
		return (numChained == 0) ? output : (Collector) chainedTasks.get(numChained - 1).getOutputCollector();
	}

	/**
	 * Sets the last output {@link Collector} of the collector chain of this {@link BatchTask}.
	 * 

* In case of chained tasks, the output collector of the last {@link ChainedDriver} is set. Otherwise it is the * single collector of the {@link BatchTask}. * * @param newOutputCollector new output collector to set as last collector */ protected void setLastOutputCollector(Collector newOutputCollector) { int numChained = this.chainedTasks.size(); if (numChained == 0) { output = newOutputCollector; return; } chainedTasks.get(numChained - 1).setOutputCollector(newOutputCollector); } public TaskConfig getLastTasksConfig() { int numChained = this.chainedTasks.size(); return (numChained == 0) ? config : chainedTasks.get(numChained - 1).getTaskConfig(); } protected S initStub(Class stubSuperClass) throws Exception { try { ClassLoader userCodeClassLoader = getUserCodeClassLoader(); S stub = config.getStubWrapper(userCodeClassLoader).getUserCodeObject(stubSuperClass, userCodeClassLoader); // check if the class is a subclass, if the check is required if (stubSuperClass != null && !stubSuperClass.isAssignableFrom(stub.getClass())) { throw new RuntimeException("The class '" + stub.getClass().getName() + "' is not a subclass of '" + stubSuperClass.getName() + "' as is required."); } FunctionUtils.setFunctionRuntimeContext(stub, this.runtimeUdfContext); return stub; } catch (ClassCastException ccex) { throw new Exception("The stub class is not a proper subclass of " + stubSuperClass.getName(), ccex); } } /** * Creates the record readers for the number of inputs as defined by {@link #getNumTaskInputs()}. * * This method requires that the task configuration, the driver, and the user-code class loader are set. */ protected void initInputReaders() throws Exception { final int numInputs = getNumTaskInputs(); final MutableReader[] inputReaders = new MutableReader[numInputs]; int currentReaderOffset = 0; for (int i = 0; i < numInputs; i++) { // ---------------- create the input readers --------------------- // in case where a logical input unions multiple physical inputs, create a union reader final int groupSize = this.config.getGroupSize(i); if (groupSize == 1) { // non-union case inputReaders[i] = new MutableRecordReader( getEnvironment().getInputGate(currentReaderOffset), getEnvironment().getTaskManagerInfo().getTmpDirectories()); } else if (groupSize > 1){ // union case InputGate[] readers = new InputGate[groupSize]; for (int j = 0; j < groupSize; ++j) { readers[j] = getEnvironment().getInputGate(currentReaderOffset + j); } inputReaders[i] = new MutableRecordReader( new UnionInputGate(readers), getEnvironment().getTaskManagerInfo().getTmpDirectories()); } else { throw new Exception("Illegal input group size in task configuration: " + groupSize); } currentReaderOffset += groupSize; } this.inputReaders = inputReaders; // final sanity check if (currentReaderOffset != this.config.getNumInputs()) { throw new Exception("Illegal configuration: Number of input gates and group sizes are not consistent."); } } /** * Creates the record readers for the extra broadcast inputs as configured by {@link TaskConfig#getNumBroadcastInputs()}. * * This method requires that the task configuration, the driver, and the user-code class loader are set. */ protected void initBroadcastInputReaders() throws Exception { final int numBroadcastInputs = this.config.getNumBroadcastInputs(); final MutableReader[] broadcastInputReaders = new MutableReader[numBroadcastInputs]; int currentReaderOffset = config.getNumInputs(); for (int i = 0; i < this.config.getNumBroadcastInputs(); i++) { // ---------------- create the input readers --------------------- // in case where a logical input unions multiple physical inputs, create a union reader final int groupSize = this.config.getBroadcastGroupSize(i); if (groupSize == 1) { // non-union case broadcastInputReaders[i] = new MutableRecordReader( getEnvironment().getInputGate(currentReaderOffset), getEnvironment().getTaskManagerInfo().getTmpDirectories()); } else if (groupSize > 1){ // union case InputGate[] readers = new InputGate[groupSize]; for (int j = 0; j < groupSize; ++j) { readers[j] = getEnvironment().getInputGate(currentReaderOffset + j); } broadcastInputReaders[i] = new MutableRecordReader( new UnionInputGate(readers), getEnvironment().getTaskManagerInfo().getTmpDirectories()); } else { throw new Exception("Illegal input group size in task configuration: " + groupSize); } currentReaderOffset += groupSize; } this.broadcastInputReaders = broadcastInputReaders; } /** * Creates all the serializers and comparators. */ protected void initInputsSerializersAndComparators(int numInputs, int numComparators) throws Exception { this.inputSerializers = new TypeSerializerFactory[numInputs]; this.inputComparators = numComparators > 0 ? new TypeComparator[numComparators] : null; this.inputIterators = new MutableObjectIterator[numInputs]; ClassLoader userCodeClassLoader = getUserCodeClassLoader(); for (int i = 0; i < numInputs; i++) { final TypeSerializerFactory serializerFactory = this.config.getInputSerializer(i, userCodeClassLoader); this.inputSerializers[i] = serializerFactory; this.inputIterators[i] = createInputIterator(this.inputReaders[i], this.inputSerializers[i]); } // ---------------- create the driver's comparators --------------------- for (int i = 0; i < numComparators; i++) { if (this.inputComparators != null) { final TypeComparatorFactory comparatorFactory = this.config.getDriverComparator(i, userCodeClassLoader); this.inputComparators[i] = comparatorFactory.createComparator(); } } } /** * Creates all the serializers and iterators for the broadcast inputs. */ protected void initBroadcastInputsSerializers(int numBroadcastInputs) throws Exception { this.broadcastInputSerializers = new TypeSerializerFactory[numBroadcastInputs]; ClassLoader userCodeClassLoader = getUserCodeClassLoader(); for (int i = 0; i < numBroadcastInputs; i++) { // ---------------- create the serializer first --------------------- final TypeSerializerFactory serializerFactory = this.config.getBroadcastInputSerializer(i, userCodeClassLoader); this.broadcastInputSerializers[i] = serializerFactory; } } /** * * NOTE: This method must be invoked after the invocation of {@code #initInputReaders()} and * {@code #initInputSerializersAndComparators(int)}! */ protected void initLocalStrategies(int numInputs) throws Exception { final MemoryManager memMan = getMemoryManager(); final IOManager ioMan = getIOManager(); this.localStrategies = new CloseableInputProvider[numInputs]; this.inputs = new MutableObjectIterator[numInputs]; this.excludeFromReset = new boolean[numInputs]; this.inputIsCached = new boolean[numInputs]; this.inputIsAsyncMaterialized = new boolean[numInputs]; this.materializationMemory = new int[numInputs]; // set up the local strategies first, such that the can work before any temp barrier is created for (int i = 0; i < numInputs; i++) { initInputLocalStrategy(i); } // we do another loop over the inputs, because we want to instantiate all // sorters, etc before requesting the first input (as this call may block) // we have two types of materialized inputs, and both are replayable (can act as a cache) // The first variant materializes in a different thread and hence // acts as a pipeline breaker. this one should only be there, if a pipeline breaker is needed. // the second variant spills to the side and will not read unless the result is also consumed // in a pipelined fashion. this.resettableInputs = new SpillingResettableMutableObjectIterator[numInputs]; this.tempBarriers = new TempBarrier[numInputs]; for (int i = 0; i < numInputs; i++) { final int memoryPages; final boolean async = this.config.isInputAsynchronouslyMaterialized(i); final boolean cached = this.config.isInputCached(i); this.inputIsAsyncMaterialized[i] = async; this.inputIsCached[i] = cached; if (async || cached) { memoryPages = memMan.computeNumberOfPages(this.config.getRelativeInputMaterializationMemory(i)); if (memoryPages <= 0) { throw new Exception("Input marked as materialized/cached, but no memory for materialization provided."); } this.materializationMemory[i] = memoryPages; } else { memoryPages = 0; } if (async) { @SuppressWarnings({ "unchecked", "rawtypes" }) TempBarrier barrier = new TempBarrier(this, getInput(i), this.inputSerializers[i], memMan, ioMan, memoryPages); barrier.startReading(); this.tempBarriers[i] = barrier; this.inputs[i] = null; } else if (cached) { @SuppressWarnings({ "unchecked", "rawtypes" }) SpillingResettableMutableObjectIterator iter = new SpillingResettableMutableObjectIterator( getInput(i), this.inputSerializers[i].getSerializer(), getMemoryManager(), getIOManager(), memoryPages, this); this.resettableInputs[i] = iter; this.inputs[i] = iter; } } } protected void resetAllInputs() throws Exception { // first we need to make sure that caches consume remaining data // NOTE: we need to do this before closing the local strategies for (int i = 0; i < this.inputs.length; i++) { if (this.inputIsCached[i] && this.resettableInputs[i] != null) { this.resettableInputs[i].consumeAndCacheRemainingData(); } } // close all local-strategies. they will either get re-initialized, or we have // read them now and their data is cached for (int i = 0; i < this.localStrategies.length; i++) { if (this.localStrategies[i] != null) { this.localStrategies[i].close(); this.localStrategies[i] = null; } } final MemoryManager memMan = getMemoryManager(); final IOManager ioMan = getIOManager(); // reset the caches, or re-run the input local strategy for (int i = 0; i < this.inputs.length; i++) { if (this.excludeFromReset[i]) { if (this.tempBarriers[i] != null) { this.tempBarriers[i].close(); this.tempBarriers[i] = null; } else if (this.resettableInputs[i] != null) { this.resettableInputs[i].close(); this.resettableInputs[i] = null; } } else { // make sure the input is not available directly, but are lazily fetched again this.inputs[i] = null; if (this.inputIsCached[i]) { if (this.tempBarriers[i] != null) { this.inputs[i] = this.tempBarriers[i].getIterator(); } else if (this.resettableInputs[i] != null) { this.resettableInputs[i].reset(); this.inputs[i] = this.resettableInputs[i]; } else { throw new RuntimeException("Found a resettable input, but no temp barrier and no resettable iterator."); } } else { // close the async barrier if there is one if (this.tempBarriers[i] != null) { this.tempBarriers[i].close(); this.tempBarriers[i] = null; } // recreate the local strategy initInputLocalStrategy(i); if (this.inputIsAsyncMaterialized[i]) { final int pages = this.materializationMemory[i]; @SuppressWarnings({ "unchecked", "rawtypes" }) TempBarrier barrier = new TempBarrier(this, getInput(i), this.inputSerializers[i], memMan, ioMan, pages); barrier.startReading(); this.tempBarriers[i] = barrier; this.inputs[i] = null; } } } } } protected void excludeFromReset(int inputNum) { this.excludeFromReset[inputNum] = true; } private void initInputLocalStrategy(int inputNum) throws Exception { // check if there is already a strategy if (this.localStrategies[inputNum] != null) { throw new IllegalStateException(); } // now set up the local strategy final LocalStrategy localStrategy = this.config.getInputLocalStrategy(inputNum); if (localStrategy != null) { switch (localStrategy) { case NONE: // the input is as it is this.inputs[inputNum] = this.inputIterators[inputNum]; break; case SORT: @SuppressWarnings({ "rawtypes", "unchecked" }) UnilateralSortMerger sorter = new UnilateralSortMerger(getMemoryManager(), getIOManager(), this.inputIterators[inputNum], this, this.inputSerializers[inputNum], getLocalStrategyComparator(inputNum), this.config.getRelativeMemoryInput(inputNum), this.config.getFilehandlesInput(inputNum), this.config.getSpillingThresholdInput(inputNum), this.config.getUseLargeRecordHandler(), this.getExecutionConfig().isObjectReuseEnabled()); // set the input to null such that it will be lazily fetched from the input strategy this.inputs[inputNum] = null; this.localStrategies[inputNum] = sorter; break; case COMBININGSORT: // sanity check this special case! // this still breaks a bit of the abstraction! // we should have nested configurations for the local strategies to solve that if (inputNum != 0) { throw new IllegalStateException("Performing combining sort outside a (group)reduce task!"); } // instantiate ourselves a combiner. we should not use the stub, because the sort and the // subsequent (group)reduce would otherwise share it multi-threaded final Class userCodeFunctionType = this.driver.getStubType(); if (userCodeFunctionType == null) { throw new IllegalStateException("Performing combining sort outside a reduce task!"); } final S localStub; try { localStub = initStub(userCodeFunctionType); } catch (Exception e) { throw new RuntimeException("Initializing the user code and the configuration failed" + (e.getMessage() == null ? "." : ": " + e.getMessage()), e); } if (!(localStub instanceof GroupCombineFunction)) { throw new IllegalStateException("Performing combining sort outside a reduce task!"); } @SuppressWarnings({ "rawtypes", "unchecked" }) CombiningUnilateralSortMerger cSorter = new CombiningUnilateralSortMerger( (GroupCombineFunction) localStub, getMemoryManager(), getIOManager(), this.inputIterators[inputNum], this, this.inputSerializers[inputNum], getLocalStrategyComparator(inputNum), this.config.getRelativeMemoryInput(inputNum), this.config.getFilehandlesInput(inputNum), this.config.getSpillingThresholdInput(inputNum), this.getTaskConfig().getUseLargeRecordHandler(), this.getExecutionConfig().isObjectReuseEnabled()); cSorter.setUdfConfiguration(this.config.getStubParameters()); // set the input to null such that it will be lazily fetched from the input strategy this.inputs[inputNum] = null; this.localStrategies[inputNum] = cSorter; break; default: throw new Exception("Unrecognized local strategy provided: " + localStrategy.name()); } } else { // no local strategy in the config this.inputs[inputNum] = this.inputIterators[inputNum]; } } private TypeComparator getLocalStrategyComparator(int inputNum) throws Exception { TypeComparatorFactory compFact = this.config.getInputComparator(inputNum, getUserCodeClassLoader()); if (compFact == null) { throw new Exception("Missing comparator factory for local strategy on input " + inputNum); } return compFact.createComparator(); } protected MutableObjectIterator createInputIterator(MutableReader inputReader, TypeSerializerFactory serializerFactory) { @SuppressWarnings("unchecked") MutableReader> reader = (MutableReader>) inputReader; @SuppressWarnings({ "unchecked", "rawtypes" }) final MutableObjectIterator iter = new ReaderIterator(reader, serializerFactory.getSerializer()); return iter; } protected int getNumTaskInputs() { return this.driver.getNumberOfInputs(); } /** * 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. */ protected void initOutputs() throws Exception { this.chainedTasks = new ArrayList>(); this.eventualOutputs = new ArrayList>(); ClassLoader userCodeClassLoader = getUserCodeClassLoader(); this.accumulatorMap = getEnvironment().getAccumulatorRegistry().getUserMap(); this.output = initOutputs(this, userCodeClassLoader, this.config, this.chainedTasks, this.eventualOutputs, this.getExecutionConfig(), this.accumulatorMap); } public DistributedRuntimeUDFContext createRuntimeContext(MetricGroup metrics) { Environment env = getEnvironment(); return new DistributedRuntimeUDFContext(env.getTaskInfo(), getUserCodeClassLoader(), getExecutionConfig(), env.getDistributedCacheEntries(), this.accumulatorMap, metrics); } // -------------------------------------------------------------------------------------------- // Task Context Signature // ------------------------------------------------------------------------------------------- @Override public TaskConfig getTaskConfig() { return this.config; } @Override public TaskManagerRuntimeInfo getTaskManagerInfo() { return getEnvironment().getTaskManagerInfo(); } @Override public MemoryManager getMemoryManager() { return getEnvironment().getMemoryManager(); } @Override public IOManager getIOManager() { return getEnvironment().getIOManager(); } @Override public S getStub() { return this.stub; } @Override public Collector getOutputCollector() { return this.output; } @Override public AbstractInvokable getContainingTask() { return this; } @Override public String formatLogString(String message) { return constructLogString(message, getEnvironment().getTaskInfo().getTaskName(), this); } @Override public OperatorMetricGroup getMetricGroup() { return metrics; } @Override public MutableObjectIterator getInput(int index) { if (index < 0 || index > this.driver.getNumberOfInputs()) { throw new IndexOutOfBoundsException(); } // check for lazy assignment from input strategies if (this.inputs[index] != null) { @SuppressWarnings("unchecked") MutableObjectIterator in = (MutableObjectIterator) this.inputs[index]; return in; } else { final MutableObjectIterator in; try { if (this.tempBarriers[index] != null) { @SuppressWarnings("unchecked") MutableObjectIterator iter = (MutableObjectIterator) this.tempBarriers[index].getIterator(); in = iter; } else if (this.localStrategies[index] != null) { @SuppressWarnings("unchecked") MutableObjectIterator iter = (MutableObjectIterator) this.localStrategies[index].getIterator(); in = iter; } else { throw new RuntimeException("Bug: null input iterator, null temp barrier, and null local strategy."); } this.inputs[index] = in; return in; } catch (InterruptedException iex) { throw new RuntimeException("Interrupted while waiting for input " + index + " to become available."); } catch (IOException ioex) { throw new RuntimeException("An I/O Exception occurred while obtaining input " + index + "."); } } } @Override public TypeSerializerFactory getInputSerializer(int index) { if (index < 0 || index >= this.driver.getNumberOfInputs()) { throw new IndexOutOfBoundsException(); } @SuppressWarnings("unchecked") final TypeSerializerFactory serializerFactory = (TypeSerializerFactory) this.inputSerializers[index]; return serializerFactory; } @Override public TypeComparator getDriverComparator(int index) { if (this.inputComparators == null) { throw new IllegalStateException("Comparators have not been created!"); } else if (index < 0 || index >= this.driver.getNumberOfDriverComparators()) { throw new IndexOutOfBoundsException(); } @SuppressWarnings("unchecked") final TypeComparator comparator = (TypeComparator) this.inputComparators[index]; return comparator; } // ============================================================================================ // Static Utilities // // Utilities are consolidated here to ensure a uniform way of running, // logging, exception handling, and error messages. // ============================================================================================ // -------------------------------------------------------------------------------------------- // Logging // -------------------------------------------------------------------------------------------- /** * 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. * * @param message The main message for the log. * @param taskName The name of the task. * @param parent The task that contains the code producing the message. * * @return The string for logging. */ public static String constructLogString(String message, String taskName, AbstractInvokable parent) { return message + ": " + taskName + " (" + (parent.getEnvironment().getTaskInfo().getIndexOfThisSubtask() + 1) + '/' + parent.getEnvironment().getTaskInfo().getNumberOfParallelSubtasks() + ')'; } /** * Prints an error message and throws the given exception. If the exception is of the type * {@link ExceptionInChainedStubException} then the chain of contained exceptions is followed * until an exception of a different type is found. * * @param ex The exception to be thrown. * @param parent The parent task, whose information is included in the log message. * @throws Exception Always thrown. */ public static void logAndThrowException(Exception ex, AbstractInvokable parent) throws Exception { String taskName; if (ex instanceof ExceptionInChainedStubException) { do { ExceptionInChainedStubException cex = (ExceptionInChainedStubException) ex; taskName = cex.getTaskName(); ex = cex.getWrappedException(); } while (ex instanceof ExceptionInChainedStubException); } else { taskName = parent.getEnvironment().getTaskInfo().getTaskName(); } if (LOG.isErrorEnabled()) { LOG.error(constructLogString("Error in task code", taskName, parent), ex); } throw ex; } // -------------------------------------------------------------------------------------------- // Result Shipping and Chained Tasks // -------------------------------------------------------------------------------------------- /** * Creates the {@link 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 the partitioning as described in the configuration. * * @param task The task that the output collector is created for. * @param config The configuration describing the output shipping strategies. * @param cl The classloader used to load user defined types. * @param eventualOutputs The output writers that this task forwards to the next task for each output. * @param outputOffset The offset to start to get the writers for the outputs * @param numOutputs The number of outputs described in the configuration. * * @return The OutputCollector that data produced in this task is submitted to. */ public static Collector getOutputCollector(AbstractInvokable task, TaskConfig config, ClassLoader cl, List> eventualOutputs, int outputOffset, int numOutputs) throws Exception { if (numOutputs == 0) { return null; } // get the factory for the serializer final TypeSerializerFactory serializerFactory = config.getOutputSerializer(cl); final List>> writers = new ArrayList<>(numOutputs); // create a writer for each output for (int i = 0; i < numOutputs; i++) { // create the OutputEmitter from output ship strategy final ShipStrategyType strategy = config.getOutputShipStrategy(i); final int indexInSubtaskGroup = task.getIndexInSubtaskGroup(); final TypeComparatorFactory compFactory = config.getOutputComparator(i, cl); final ChannelSelector> oe; if (compFactory == null) { oe = new OutputEmitter(strategy, indexInSubtaskGroup); } else { final DataDistribution dataDist = config.getOutputDataDistribution(i, cl); final Partitioner partitioner = config.getOutputPartitioner(i, cl); final TypeComparator comparator = compFactory.createComparator(); oe = new OutputEmitter(strategy, indexInSubtaskGroup, comparator, partitioner, dataDist); } final RecordWriter> recordWriter = new RecordWriterBuilder() .setChannelSelector(oe) .setTaskName(task.getEnvironment().getTaskInfo().getTaskName()) .build(task.getEnvironment().getWriter(outputOffset + i)); recordWriter.setMetricGroup(task.getEnvironment().getMetricGroup().getIOMetricGroup()); writers.add(recordWriter); } if (eventualOutputs != null) { eventualOutputs.addAll(writers); } return new OutputCollector(writers, serializerFactory.getSerializer()); } /** * Creates a writer for each output. Creates an OutputCollector which forwards its input to all writers. * The output collector applies the configured shipping strategy. */ @SuppressWarnings("unchecked") public static Collector initOutputs(AbstractInvokable containingTask, ClassLoader cl, TaskConfig config, List> chainedTasksTarget, List> eventualOutputs, ExecutionConfig executionConfig, Map> accumulatorMap) throws Exception { final int numOutputs = config.getNumOutputs(); // check whether we got any chained tasks final int numChained = config.getNumberOfChainedStubs(); if (numChained > 0) { // got chained stubs. that means that this one may only have a single forward connection if (numOutputs != 1 || config.getOutputShipStrategy(0) != ShipStrategyType.FORWARD) { throw new RuntimeException("Plan Generation Bug: Found a chained stub that is not connected via an only forward connection."); } // instantiate each task @SuppressWarnings("rawtypes") Collector previous = null; for (int i = numChained - 1; i >= 0; --i) { // get the task first final ChainedDriver ct; try { Class> ctc = config.getChainedTask(i); ct = ctc.newInstance(); } catch (Exception ex) { throw new RuntimeException("Could not instantiate chained task driver.", ex); } // get the configuration for the task final TaskConfig chainedStubConf = config.getChainedStubConfig(i); final String taskName = config.getChainedTaskName(i); if (i == numChained - 1) { // last in chain, instantiate the output collector for this task previous = getOutputCollector(containingTask, chainedStubConf, cl, eventualOutputs, 0, chainedStubConf.getNumOutputs()); } ct.setup(chainedStubConf, taskName, previous, containingTask, cl, executionConfig, accumulatorMap); chainedTasksTarget.add(0, ct); if (i == numChained - 1) { ct.getIOMetrics().reuseOutputMetricsForTask(); } previous = ct; } // the collector of the first in the chain is the collector for the task return (Collector) previous; } // else // instantiate the output collector the default way from this configuration return getOutputCollector(containingTask , config, cl, eventualOutputs, 0, numOutputs); } // -------------------------------------------------------------------------------------------- // User Code LifeCycle // -------------------------------------------------------------------------------------------- /** * Opens the given stub using its {@link org.apache.flink.api.common.functions.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. * * @param stub The user code instance to be opened. * @param parameters The parameters supplied to the user code. * * @throws Exception Thrown, if the user code's open method produces an exception. */ public static void openUserCode(Function stub, Configuration parameters) throws Exception { try { FunctionUtils.openFunction(stub, parameters); } catch (Throwable t) { throw new Exception("The user defined 'open(Configuration)' method in " + stub.getClass().toString() + " caused an exception: " + t.getMessage(), t); } } /** * Closes the given stub using its {@link org.apache.flink.api.common.functions.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. * * @param stub The user code instance to be closed. * * @throws Exception Thrown, if the user code's close method produces an exception. */ public static void closeUserCode(Function stub) throws Exception { try { FunctionUtils.closeFunction(stub); } catch (Throwable t) { throw new Exception("The user defined 'close()' method caused an exception: " + t.getMessage(), t); } } // -------------------------------------------------------------------------------------------- // Chained Task LifeCycle // -------------------------------------------------------------------------------------------- /** * Opens all chained tasks, in the order as they are stored in the array. The opening process * creates a standardized log info message. * * @param tasks The tasks to be opened. * @param parent The parent task, used to obtain parameters to include in the log message. * @throws Exception Thrown, if the opening encounters an exception. */ public static void openChainedTasks(List> tasks, AbstractInvokable parent) throws Exception { // start all chained tasks for (int i = 0; i < tasks.size(); i++) { final ChainedDriver task = tasks.get(i); if (LOG.isDebugEnabled()) { LOG.debug(constructLogString("Start task code", task.getTaskName(), parent)); } task.openTask(); } } /** * Closes all chained tasks, in the order as they are stored in the array. The closing process * creates a standardized log info message. * * @param tasks The tasks to be closed. * @param parent The parent task, used to obtain parameters to include in the log message. * @throws Exception Thrown, if the closing encounters an exception. */ public static void closeChainedTasks(List> tasks, AbstractInvokable parent) throws Exception { for (int i = 0; i < tasks.size(); i++) { final ChainedDriver task = tasks.get(i); task.closeTask(); if (LOG.isDebugEnabled()) { LOG.debug(constructLogString("Finished task code", task.getTaskName(), parent)); } } } /** * Cancels all tasks via their {@link ChainedDriver#cancelTask()} method. Any occurring exception * and error is suppressed, such that the canceling method of every task is invoked in all cases. * * @param tasks The tasks to be canceled. */ public static void cancelChainedTasks(List> tasks) { for (int i = 0; i < tasks.size(); i++) { try { tasks.get(i).cancelTask(); } catch (Throwable t) { // do nothing } } } // -------------------------------------------------------------------------------------------- // Miscellaneous Utilities // -------------------------------------------------------------------------------------------- /** * 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. * * @param The generic type of the user code class. * @param config The task configuration containing the class description. * @param cl The class loader to be used to load the class. * @param superClass The super class that the user code class extends or implements, for type checking. * * @return An instance of the user code class. */ public static T instantiateUserCode(TaskConfig config, ClassLoader cl, Class superClass) { try { T stub = config.getStubWrapper(cl).getUserCodeObject(superClass, cl); // check if the class is a subclass, if the check is required if (superClass != null && !superClass.isAssignableFrom(stub.getClass())) { throw new RuntimeException("The class '" + stub.getClass().getName() + "' is not a subclass of '" + superClass.getName() + "' as is required."); } return stub; } catch (ClassCastException ccex) { throw new RuntimeException("The UDF class is not a proper subclass of " + superClass.getName(), ccex); } } private static int[] asArray(List list) { int[] a = new int[list.size()]; int i = 0; for (int val : list) { a[i++] = val; } return a; } public static void clearWriters(List> writers) { for (RecordWriter writer : writers) { writer.clearBuffers(); } } public static void clearReaders(MutableReader[] readers) { for (MutableReader reader : readers) { reader.clearBuffers(); } } }