Java tutorial
/*********************************************************************************************************************** * Copyright (C) 2010-2013 by the Stratosphere project (http://stratosphere.eu) * * Licensed 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 eu.stratosphere.compiler; import java.io.IOException; import java.net.InetSocketAddress; import java.util.ArrayDeque; import java.util.ArrayList; import java.util.Deque; import java.util.HashMap; import java.util.HashSet; import java.util.Iterator; import java.util.List; import java.util.Map; import java.util.Set; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import eu.stratosphere.api.common.Plan; import eu.stratosphere.api.common.operators.Operator; import eu.stratosphere.api.common.operators.Union; import eu.stratosphere.api.common.operators.base.BulkIterationBase; import eu.stratosphere.api.common.operators.base.BulkIterationBase.PartialSolutionPlaceHolder; import eu.stratosphere.api.common.operators.base.CoGroupOperatorBase; import eu.stratosphere.api.common.operators.base.CollectorMapOperatorBase; import eu.stratosphere.api.common.operators.base.CrossOperatorBase; import eu.stratosphere.api.common.operators.base.DeltaIterationBase; import eu.stratosphere.api.common.operators.base.DeltaIterationBase.SolutionSetPlaceHolder; import eu.stratosphere.api.common.operators.base.DeltaIterationBase.WorksetPlaceHolder; import eu.stratosphere.api.common.operators.base.FilterOperatorBase; import eu.stratosphere.api.common.operators.base.FlatMapOperatorBase; import eu.stratosphere.api.common.operators.base.GenericDataSinkBase; import eu.stratosphere.api.common.operators.base.GenericDataSourceBase; import eu.stratosphere.api.common.operators.base.GroupReduceOperatorBase; import eu.stratosphere.api.common.operators.base.JoinOperatorBase; import eu.stratosphere.api.common.operators.base.MapOperatorBase; import eu.stratosphere.api.common.operators.base.ReduceOperatorBase; import eu.stratosphere.compiler.costs.CostEstimator; import eu.stratosphere.compiler.costs.DefaultCostEstimator; import eu.stratosphere.compiler.dag.BinaryUnionNode; import eu.stratosphere.compiler.dag.BulkIterationNode; import eu.stratosphere.compiler.dag.BulkPartialSolutionNode; import eu.stratosphere.compiler.dag.CoGroupNode; import eu.stratosphere.compiler.dag.CollectorMapNode; import eu.stratosphere.compiler.dag.CrossNode; import eu.stratosphere.compiler.dag.DataSinkNode; import eu.stratosphere.compiler.dag.DataSourceNode; import eu.stratosphere.compiler.dag.FilterNode; import eu.stratosphere.compiler.dag.FlatMapNode; import eu.stratosphere.compiler.dag.GroupReduceNode; import eu.stratosphere.compiler.dag.IterationNode; import eu.stratosphere.compiler.dag.MapNode; import eu.stratosphere.compiler.dag.MatchNode; import eu.stratosphere.compiler.dag.OptimizerNode; import eu.stratosphere.compiler.dag.PactConnection; import eu.stratosphere.compiler.dag.ReduceNode; import eu.stratosphere.compiler.dag.SinkJoiner; import eu.stratosphere.compiler.dag.SolutionSetNode; import eu.stratosphere.compiler.dag.TempMode; import eu.stratosphere.compiler.dag.WorksetIterationNode; import eu.stratosphere.compiler.dag.WorksetNode; import eu.stratosphere.compiler.deadlockdetect.DeadlockPreventer; import eu.stratosphere.compiler.plan.BinaryUnionPlanNode; import eu.stratosphere.compiler.plan.BulkIterationPlanNode; import eu.stratosphere.compiler.plan.BulkPartialSolutionPlanNode; import eu.stratosphere.compiler.plan.Channel; import eu.stratosphere.compiler.plan.IterationPlanNode; import eu.stratosphere.compiler.plan.NAryUnionPlanNode; import eu.stratosphere.compiler.plan.OptimizedPlan; import eu.stratosphere.compiler.plan.PlanNode; import eu.stratosphere.compiler.plan.SinkJoinerPlanNode; import eu.stratosphere.compiler.plan.SinkPlanNode; import eu.stratosphere.compiler.plan.SolutionSetPlanNode; import eu.stratosphere.compiler.plan.SourcePlanNode; import eu.stratosphere.compiler.plan.WorksetIterationPlanNode; import eu.stratosphere.compiler.plan.WorksetPlanNode; import eu.stratosphere.compiler.postpass.OptimizerPostPass; import eu.stratosphere.configuration.ConfigConstants; import eu.stratosphere.configuration.Configuration; import eu.stratosphere.configuration.GlobalConfiguration; import eu.stratosphere.nephele.instance.InstanceType; import eu.stratosphere.nephele.instance.InstanceTypeDescription; import eu.stratosphere.nephele.ipc.RPC; import eu.stratosphere.nephele.net.NetUtils; import eu.stratosphere.nephele.protocols.ExtendedManagementProtocol; import eu.stratosphere.pact.runtime.shipping.ShipStrategyType; import eu.stratosphere.pact.runtime.task.util.LocalStrategy; import eu.stratosphere.util.InstantiationUtil; import eu.stratosphere.util.Visitor; /** * The optimizer that takes the user specified program plan and creates an optimized plan that contains * exact descriptions about how the physical execution will take place. It first translates the user * program into an internal optimizer representation and then chooses between different alternatives * for shipping strategies and local strategies. * <p> * The basic principle is taken from optimizer works in systems such as Volcano/Cascades and Selinger/System-R/DB2. The * optimizer walks from the sinks down, generating interesting properties, and ascends from the sources generating * alternative plans, pruning against the interesting properties. * <p> * The optimizer also assigns the memory to the individual tasks. This is currently done in a very simple fashion: All * sub-tasks that need memory (e.g. reduce or join) are given an equal share of memory. */ public class PactCompiler { // ------------------------------------------------------------------------ // Constants // ------------------------------------------------------------------------ /** * Compiler hint key for the input channel's shipping strategy. This String is a key to the operator's stub * parameters. The corresponding value tells the compiler which shipping strategy to use for the input channel. * If the operator has two input channels, the shipping strategy is applied to both input channels. */ public static final String HINT_SHIP_STRATEGY = "INPUT_SHIP_STRATEGY"; /** * Compiler hint key for the <b>first</b> input channel's shipping strategy. This String is a key to * the operator's stub parameters. The corresponding value tells the compiler which shipping strategy * to use for the <b>first</b> input channel. Only applicable to operators with two inputs. */ public static final String HINT_SHIP_STRATEGY_FIRST_INPUT = "INPUT_LEFT_SHIP_STRATEGY"; /** * Compiler hint key for the <b>second</b> input channel's shipping strategy. This String is a key to * the operator's stub parameters. The corresponding value tells the compiler which shipping strategy * to use for the <b>second</b> input channel. Only applicable to operators with two inputs. */ public static final String HINT_SHIP_STRATEGY_SECOND_INPUT = "INPUT_RIGHT_SHIP_STRATEGY"; /** * Value for the shipping strategy compiler hint that enforces a <b>Forward</b> strategy on the * input channel, i.e. no redistribution of any kind. * * @see #HINT_SHIP_STRATEGY * @see #HINT_SHIP_STRATEGY_FIRST_INPUT * @see #HINT_SHIP_STRATEGY_SECOND_INPUT */ public static final String HINT_SHIP_STRATEGY_FORWARD = "SHIP_FORWARD"; /** * Value for the shipping strategy compiler hint that enforces a random repartition strategy. * * @see #HINT_SHIP_STRATEGY * @see #HINT_SHIP_STRATEGY_FIRST_INPUT * @see #HINT_SHIP_STRATEGY_SECOND_INPUT */ public static final String HINT_SHIP_STRATEGY_REPARTITION = "SHIP_REPARTITION"; /** * Value for the shipping strategy compiler hint that enforces a hash-partition strategy. * * @see #HINT_SHIP_STRATEGY * @see #HINT_SHIP_STRATEGY_FIRST_INPUT * @see #HINT_SHIP_STRATEGY_SECOND_INPUT */ public static final String HINT_SHIP_STRATEGY_REPARTITION_HASH = "SHIP_REPARTITION_HASH"; /** * Value for the shipping strategy compiler hint that enforces a range-partition strategy. * * @see #HINT_SHIP_STRATEGY * @see #HINT_SHIP_STRATEGY_FIRST_INPUT * @see #HINT_SHIP_STRATEGY_SECOND_INPUT */ public static final String HINT_SHIP_STRATEGY_REPARTITION_RANGE = "SHIP_REPARTITION_RANGE"; /** * Value for the shipping strategy compiler hint that enforces a <b>broadcast</b> strategy on the * input channel. * * @see #HINT_SHIP_STRATEGY * @see #HINT_SHIP_STRATEGY_FIRST_INPUT * @see #HINT_SHIP_STRATEGY_SECOND_INPUT */ public static final String HINT_SHIP_STRATEGY_BROADCAST = "SHIP_BROADCAST"; /** * Compiler hint key for the operator's local strategy. This String is a key to the operator's stub * parameters. The corresponding value tells the compiler which local strategy to use to process the * data inside one partition. * <p> * This hint is ignored by operators that do not have a local strategy (such as <i>Map</i>), or by operators that * have no choice in their local strategy (such as <i>Cross</i>). */ public static final String HINT_LOCAL_STRATEGY = "LOCAL_STRATEGY"; /** * Value for the local strategy compiler hint that enforces a <b>sort based</b> local strategy. * For example, a <i>Reduce</i> operator will sort the data to group it. * * @see #HINT_LOCAL_STRATEGY */ public static final String HINT_LOCAL_STRATEGY_SORT = "LOCAL_STRATEGY_SORT"; /** * Value for the local strategy compiler hint that enforces a <b>sort based</b> local strategy. * During sorting a combine method is repeatedly applied to reduce the data volume. * For example, a <i>Reduce</i> operator will sort the data to group it. * * @see #HINT_LOCAL_STRATEGY */ public static final String HINT_LOCAL_STRATEGY_COMBINING_SORT = "LOCAL_STRATEGY_COMBINING_SORT"; /** * Value for the local strategy compiler hint that enforces a <b>sort merge based</b> local strategy on both * inputs with subsequent merging of inputs. * For example, a <i>Match</i> or <i>CoGroup</i> operator will use a sort-merge strategy to find pairs * of matching keys. * * @see #HINT_LOCAL_STRATEGY */ public static final String HINT_LOCAL_STRATEGY_SORT_BOTH_MERGE = "LOCAL_STRATEGY_SORT_BOTH_MERGE"; /** * Value for the local strategy compiler hint that enforces a <b>sort merge based</b> local strategy. * The the first input is sorted, the second input is assumed to be sorted. After sorting both inputs are merged. * For example, a <i>Match</i> or <i>CoGroup</i> operator will use a sort-merge strategy to find pairs * of matching keys. * * @see #HINT_LOCAL_STRATEGY */ public static final String HINT_LOCAL_STRATEGY_SORT_FIRST_MERGE = "LOCAL_STRATEGY_SORT_FIRST_MERGE"; /** * Value for the local strategy compiler hint that enforces a <b>sort merge based</b> local strategy. * The the second input is sorted, the first input is assumed to be sorted. After sorting both inputs are merged. * For example, a <i>Match</i> or <i>CoGroup</i> operator will use a sort-merge strategy to find pairs * of matching keys. * * @see #HINT_LOCAL_STRATEGY */ public static final String HINT_LOCAL_STRATEGY_SORT_SECOND_MERGE = "LOCAL_STRATEGY_SORT_SECOND_MERGE"; /** * Value for the local strategy compiler hint that enforces a <b>merge based</b> local strategy. * Both inputs are assumed to be sorted and are merged. * For example, a <i>Match</i> or <i>CoGroup</i> operator will use a merge strategy to find pairs * of matching keys. * * @see #HINT_LOCAL_STRATEGY */ public static final String HINT_LOCAL_STRATEGY_MERGE = "LOCAL_STRATEGY_MERGE"; /** * Value for the local strategy compiler hint that enforces a <b>hash based</b> local strategy. * For example, a <i>Match</i> operator will use a hybrid-hash-join strategy to find pairs of * matching keys. The <b>first</b> input will be used to build the hash table, the second input will be * used to probe the table. * * @see #HINT_LOCAL_STRATEGY */ public static final String HINT_LOCAL_STRATEGY_HASH_BUILD_FIRST = "LOCAL_STRATEGY_HASH_BUILD_FIRST"; /** * Value for the local strategy compiler hint that enforces a <b>hash based</b> local strategy. * For example, a <i>Match</i> operator will use a hybrid-hash-join strategy to find pairs of * matching keys. The <b>second</b> input will be used to build the hash table, the first input will be * used to probe the table. * * @see #HINT_LOCAL_STRATEGY */ public static final String HINT_LOCAL_STRATEGY_HASH_BUILD_SECOND = "LOCAL_STRATEGY_HASH_BUILD_SECOND"; /** * Value for the local strategy compiler hint that chooses the outer side of the <b>nested-loop</b> local strategy. * A <i>Cross</i> operator will process the data of the <b>first</b> input in the outer-loop of the nested loops. * Hence, the data of the first input will be is streamed though, while the data of the second input is stored on * disk * and repeatedly read. * * @see #HINT_LOCAL_STRATEGY */ public static final String HINT_LOCAL_STRATEGY_NESTEDLOOP_STREAMED_OUTER_FIRST = "LOCAL_STRATEGY_NESTEDLOOP_STREAMED_OUTER_FIRST"; /** * Value for the local strategy compiler hint that chooses the outer side of the <b>nested-loop</b> local strategy. * A <i>Cross</i> operator will process the data of the <b>second</b> input in the outer-loop of the nested loops. * Hence, the data of the second input will be is streamed though, while the data of the first input is stored on * disk * and repeatedly read. * * @see #HINT_LOCAL_STRATEGY */ public static final String HINT_LOCAL_STRATEGY_NESTEDLOOP_STREAMED_OUTER_SECOND = "LOCAL_STRATEGY_NESTEDLOOP_STREAMED_OUTER_SECOND"; /** * Value for the local strategy compiler hint that chooses the outer side of the <b>nested-loop</b> local strategy. * A <i>Cross</i> operator will process the data of the <b>first</b> input in the outer-loop of the nested loops. * Further more, the first input, being the outer side, will be processed in blocks, and for each block, the second * input, * being the inner side, will read repeatedly from disk. * * @see #HINT_LOCAL_STRATEGY */ public static final String HINT_LOCAL_STRATEGY_NESTEDLOOP_BLOCKED_OUTER_FIRST = "LOCAL_STRATEGY_NESTEDLOOP_BLOCKED_OUTER_FIRST"; /** * Value for the local strategy compiler hint that chooses the outer side of the <b>nested-loop</b> local strategy. * A <i>Cross</i> operator will process the data of the <b>second</b> input in the outer-loop of the nested loops. * Further more, the second input, being the outer side, will be processed in blocks, and for each block, the first * input, * being the inner side, will read repeatedly from disk. * * @see #HINT_LOCAL_STRATEGY */ public static final String HINT_LOCAL_STRATEGY_NESTEDLOOP_BLOCKED_OUTER_SECOND = "LOCAL_STRATEGY_NESTEDLOOP_BLOCKED_OUTER_SECOND"; /** * The log handle that is used by the compiler to log messages. */ public static final Log LOG = LogFactory.getLog(PactCompiler.class); // ------------------------------------------------------------------------ // Members // ------------------------------------------------------------------------ /** * The statistics object used to obtain statistics, such as input sizes, * for the cost estimation process. */ private final DataStatistics statistics; /** * The cost estimator used by the compiler. */ private final CostEstimator costEstimator; /** * The connection used to connect to the job-manager. */ private final InetSocketAddress jobManagerAddress; /** * The maximum number of machines (instances) to use, per the configuration. */ private int maxMachines; /** * The default degree of parallelism for jobs compiled by this compiler. */ private int defaultDegreeOfParallelism; /** * The maximum number of subtasks that should share an instance. */ private int maxIntraNodeParallelism; // ------------------------------------------------------------------------ // Constructor & Setup // ------------------------------------------------------------------------ /** * Creates a new compiler instance. The compiler has no access to statistics about the * inputs and can hence not determine any properties. It will perform all optimization with * unknown sizes and default to the most robust execution strategies. The * compiler also uses conservative default estimates for the operator costs, since * it has no access to another cost estimator. * <p> * The address of the job manager (to obtain system characteristics) is determined via the global configuration. */ public PactCompiler() { this(null, new DefaultCostEstimator()); } /** * Creates a new compiler instance that uses the statistics object to determine properties about the input. * Given those statistics, the compiler can make better choices for the execution strategies. * as if no filesystem was given. The compiler uses conservative default estimates for the operator costs, since * it has no access to another cost estimator. * <p> * The address of the job manager (to obtain system characteristics) is determined via the global configuration. * * @param stats * The statistics to be used to determine the input properties. */ public PactCompiler(DataStatistics stats) { this(stats, new DefaultCostEstimator()); } /** * Creates a new compiler instance. The compiler has no access to statistics about the * inputs and can hence not determine any properties. It will perform all optimization with * unknown sizes and default to the most robust execution strategies. It uses * however the given cost estimator to compute the costs of the individual operations. * <p> * The address of the job manager (to obtain system characteristics) is determined via the global configuration. * * @param estimator * The <tt>CostEstimator</tt> to use to cost the individual operations. */ public PactCompiler(CostEstimator estimator) { this(null, estimator); } /** * Creates a new compiler instance that uses the statistics object to determine properties about the input. * Given those statistics, the compiler can make better choices for the execution strategies. * as if no filesystem was given. It uses the given cost estimator to compute the costs of the individual * operations. * <p> * The address of the job manager (to obtain system characteristics) is determined via the global configuration. * * @param stats * The statistics to be used to determine the input properties. * @param estimator * The <tt>CostEstimator</tt> to use to cost the individual operations. */ public PactCompiler(DataStatistics stats, CostEstimator estimator) { this(stats, estimator, null); } /** * Creates a new compiler instance that uses the statistics object to determine properties about the input. * Given those statistics, the compiler can make better choices for the execution strategies. * as if no filesystem was given. It uses the given cost estimator to compute the costs of the individual * operations. * <p> * The given socket-address is used to connect to the job manager to obtain system characteristics, like available * memory. If that parameter is null, then the address is obtained from the global configuration. * * @param stats * The statistics to be used to determine the input properties. * @param estimator * The <tt>CostEstimator</tt> to use to cost the individual operations. * @param jobManagerConnection * The address of the job manager that is queried for system characteristics. */ public PactCompiler(DataStatistics stats, CostEstimator estimator, InetSocketAddress jobManagerConnection) { this.statistics = stats; this.costEstimator = estimator; Configuration config = GlobalConfiguration.getConfiguration(); // determine the maximum number of instances to use this.maxMachines = -1; // determine the default parallelization degree this.defaultDegreeOfParallelism = config.getInteger(ConfigConstants.DEFAULT_PARALLELIZATION_DEGREE_KEY, ConfigConstants.DEFAULT_PARALLELIZATION_DEGREE); // determine the default intra-node parallelism int maxInNodePar = config.getInteger(ConfigConstants.PARALLELIZATION_MAX_INTRA_NODE_DEGREE_KEY, ConfigConstants.DEFAULT_MAX_INTRA_NODE_PARALLELIZATION_DEGREE); if (maxInNodePar == 0 || maxInNodePar < -1) { LOG.error( "Invalid maximum degree of intra-node parallelism: " + maxInNodePar + ". Ignoring parameter."); maxInNodePar = ConfigConstants.DEFAULT_MAX_INTRA_NODE_PARALLELIZATION_DEGREE; } this.maxIntraNodeParallelism = maxInNodePar; // assign the connection to the job-manager if (jobManagerConnection != null) { this.jobManagerAddress = jobManagerConnection; } else { final String address = config.getString(ConfigConstants.JOB_MANAGER_IPC_ADDRESS_KEY, null); if (address == null) { throw new CompilerException( "Cannot find address to job manager's RPC service in the global configuration."); } final int port = GlobalConfiguration.getInteger(ConfigConstants.JOB_MANAGER_IPC_PORT_KEY, ConfigConstants.DEFAULT_JOB_MANAGER_IPC_PORT); if (port < 0) { throw new CompilerException( "Cannot find port to job manager's RPC service in the global configuration."); } this.jobManagerAddress = new InetSocketAddress(address, port); } } // ------------------------------------------------------------------------ // Getters / Setters // ------------------------------------------------------------------------ public int getMaxMachines() { return maxMachines; } public void setMaxMachines(int maxMachines) { if (maxMachines == -1 || maxMachines > 0) { this.maxMachines = maxMachines; } else { throw new IllegalArgumentException(); } } public int getDefaultDegreeOfParallelism() { return defaultDegreeOfParallelism; } public void setDefaultDegreeOfParallelism(int defaultDegreeOfParallelism) { if (defaultDegreeOfParallelism == -1 || defaultDegreeOfParallelism > 0) { this.defaultDegreeOfParallelism = defaultDegreeOfParallelism; } else { throw new IllegalArgumentException(); } } public int getMaxIntraNodeParallelism() { return maxIntraNodeParallelism; } public void setMaxIntraNodeParallelism(int maxIntraNodeParallelism) { if (maxIntraNodeParallelism == -1 || maxIntraNodeParallelism > 0) { this.maxIntraNodeParallelism = maxIntraNodeParallelism; } else { throw new IllegalArgumentException(); } } // ------------------------------------------------------------------------ // Compilation // ------------------------------------------------------------------------ /** * Translates the given plan in to an OptimizedPlan, where all nodes have their local strategy assigned * and all channels have a shipping strategy assigned. The compiler connects to the job manager to obtain information * about the available instances and their memory and then chooses an instance type to schedule the execution on. * <p> * The compilation process itself goes through several phases: * <ol> * <li>Create an optimizer data flow representation of the program, assign parallelism and compute size estimates.</li> * <li>Compute interesting properties and auxiliary structures.</li> * <li>Enumerate plan alternatives. This cannot be done in the same step as the interesting property computation (as * opposed to the Database approaches), because we support plans that are not trees.</li> * </ol> * * @param program The program to be translated. * @return The optimized plan. * @throws CompilerException * Thrown, if the plan is invalid or the optimizer encountered an inconsistent * situation during the compilation process. */ public OptimizedPlan compile(Plan program) throws CompilerException { // -------------------- try to get the connection to the job manager ---------------------- // --------------------------to obtain instance information -------------------------------- final OptimizerPostPass postPasser = getPostPassFromPlan(program); return compile(program, getInstanceTypeInfo(), postPasser); } public OptimizedPlan compile(Plan program, InstanceTypeDescription type) throws CompilerException { final OptimizerPostPass postPasser = getPostPassFromPlan(program); return compile(program, type, postPasser); } /** * Translates the given pact plan in to an OptimizedPlan, where all nodes have their local strategy assigned * and all channels have a shipping strategy assigned. The process goes through several phases: * <ol> * <li>Create <tt>OptimizerNode</tt> representations of the PACTs, assign parallelism and compute size estimates.</li> * <li>Compute interesting properties and auxiliary structures.</li> * <li>Enumerate plan alternatives. This cannot be done in the same step as the interesting property computation (as * opposed to the Database approaches), because we support plans that are not trees.</li> * </ol> * * @param program The program to be translated. * @param type The instance type to schedule the execution on. Used also to determine the amount of memory * available to the tasks. * @param postPasser The function to be used for post passing the optimizer's plan and setting the * data type specific serialization routines. * @return The optimized plan. * * @throws CompilerException * Thrown, if the plan is invalid or the optimizer encountered an inconsistent * situation during the compilation process. */ private OptimizedPlan compile(Plan program, InstanceTypeDescription type, OptimizerPostPass postPasser) throws CompilerException { if (program == null || type == null || postPasser == null) { throw new NullPointerException(); } if (LOG.isDebugEnabled()) { LOG.debug("Beginning compilation of program '" + program.getJobName() + '\''); } final String instanceName = type.getInstanceType().getIdentifier(); // we subtract some percentage of the memory to accommodate for rounding errors final long memoryPerInstance = (long) (type.getHardwareDescription().getSizeOfFreeMemory() * 0.96f); final int numInstances = type.getMaximumNumberOfAvailableInstances(); // determine the maximum number of machines to use int maxMachinesJob = program.getMaxNumberMachines(); if (maxMachinesJob < 1) { maxMachinesJob = this.maxMachines; } else if (this.maxMachines >= 1) { // check if the program requested more than the global config allowed if (maxMachinesJob > this.maxMachines && LOG.isWarnEnabled()) { LOG.warn("Maximal number of machines specified in program (" + maxMachinesJob + ") exceeds the maximum number in the global configuration (" + this.maxMachines + "). Using the global configuration value."); } maxMachinesJob = Math.min(maxMachinesJob, this.maxMachines); } // adjust the maximum number of machines the the number of available instances if (maxMachinesJob < 1) { maxMachinesJob = numInstances; } else if (maxMachinesJob > numInstances) { maxMachinesJob = numInstances; if (LOG.isInfoEnabled()) { LOG.info("Maximal number of machines decreased to " + maxMachinesJob + " because no more instances are available."); } } // set the default degree of parallelism int defaultParallelism = program.getDefaultParallelism() > 0 ? program.getDefaultParallelism() : this.defaultDegreeOfParallelism; if (this.maxIntraNodeParallelism > 0) { if (defaultParallelism < 1) { defaultParallelism = maxMachinesJob * this.maxIntraNodeParallelism; } else if (defaultParallelism > maxMachinesJob * this.maxIntraNodeParallelism) { int oldParallelism = defaultParallelism; defaultParallelism = maxMachinesJob * this.maxIntraNodeParallelism; if (LOG.isInfoEnabled()) { LOG.info("Decreasing default degree of parallelism from " + oldParallelism + " to " + defaultParallelism + " to fit a maximum number of " + maxMachinesJob + " instances with a intra-parallelism of " + this.maxIntraNodeParallelism); } } } else if (defaultParallelism < 1) { defaultParallelism = maxMachinesJob; if (LOG.isInfoEnabled()) { LOG.info("No default parallelism specified. Using default parallelism of " + defaultParallelism + " (One task per instance)"); } } // log the output if (LOG.isDebugEnabled()) { LOG.debug("Using a default degree of parallelism of " + defaultParallelism + ", a maximum intra-node parallelism of " + this.maxIntraNodeParallelism + '.'); if (this.maxMachines > 0) { LOG.debug("The execution is limited to a maximum number of " + maxMachinesJob + " machines."); } } // the first step in the compilation is to create the optimizer plan representation // this step does the following: // 1) It creates an optimizer plan node for each operator // 2) It connects them via channels // 3) It looks for hints about local strategies and channel types and // sets the types and strategies accordingly // 4) It makes estimates about the data volume of the data sources and // propagates those estimates through the plan GraphCreatingVisitor graphCreator = new GraphCreatingVisitor(maxMachinesJob, defaultParallelism); program.accept(graphCreator); // if we have a plan with multiple data sinks, add logical optimizer nodes that have two data-sinks as children // each until we have only a single root node. This allows to transparently deal with the nodes with // multiple outputs OptimizerNode rootNode; if (graphCreator.sinks.size() == 1) { rootNode = graphCreator.sinks.get(0); } else if (graphCreator.sinks.size() > 1) { Iterator<DataSinkNode> iter = graphCreator.sinks.iterator(); rootNode = iter.next(); while (iter.hasNext()) { rootNode = new SinkJoiner(rootNode, iter.next()); } } else { throw new CompilerException("Bug: The optimizer plan representation has no sinks."); } // now that we have all nodes created and recorded which ones consume memory, tell the nodes their minimal // guaranteed memory, for further cost estimations. we assume an equal distribution of memory among consumer tasks rootNode.accept( new IdAndMemoryAndEstimatesVisitor(this.statistics, graphCreator.getMemoryConsumerCount() == 0 ? 0 : memoryPerInstance / graphCreator.getMemoryConsumerCount())); // Now that the previous step is done, the next step is to traverse the graph again for the two // steps that cannot directly be performed during the plan enumeration, because we are dealing with DAGs // rather than a trees. That requires us to deviate at some points from the classical DB optimizer algorithms. // // 1) propagate the interesting properties top-down through the graph // 2) Track information about nodes with multiple outputs that are later on reconnected in a node with // multiple inputs. InterestingPropertyVisitor propsVisitor = new InterestingPropertyVisitor(this.costEstimator); rootNode.accept(propsVisitor); BranchesVisitor branchingVisitor = new BranchesVisitor(); rootNode.accept(branchingVisitor); // perform a sanity check: the root may not have any unclosed branches if (rootNode.getOpenBranches() != null && rootNode.getOpenBranches().size() > 0) { throw new CompilerException( "Bug: Logic for branching plans (non-tree plans) has an error, and does not " + "track the re-joining of branches correctly."); } // the final step is now to generate the actual plan alternatives List<PlanNode> bestPlan = rootNode.getAlternativePlans(this.costEstimator); if (bestPlan.size() != 1) { throw new CompilerException("Error in compiler: more than one best plan was created!"); } // check if the best plan's root is a data sink (single sink plan) // if so, directly take it. if it is a sink joiner node, get its contained sinks PlanNode bestPlanRoot = bestPlan.get(0); List<SinkPlanNode> bestPlanSinks = new ArrayList<SinkPlanNode>(4); if (bestPlanRoot instanceof SinkPlanNode) { bestPlanSinks.add((SinkPlanNode) bestPlanRoot); } else if (bestPlanRoot instanceof SinkJoinerPlanNode) { ((SinkJoinerPlanNode) bestPlanRoot).getDataSinks(bestPlanSinks); } DeadlockPreventer dp = new DeadlockPreventer(); dp.resolveDeadlocks(bestPlanSinks); // finalize the plan OptimizedPlan plan = new PlanFinalizer().createFinalPlan(bestPlanSinks, program.getJobName(), program, memoryPerInstance); plan.setInstanceTypeName(instanceName); // swap the binary unions for n-ary unions. this changes no strategies or memory consumers whatsoever, so // we can do this after the plan finalization plan.accept(new BinaryUnionReplacer()); // post pass the plan. this is the phase where the serialization and comparator code is set postPasser.postPass(plan); return plan; } /** * This function performs only the first step to the compilation process - the creation of the optimizer * representation of the plan. No estimations or enumerations of alternatives are done here. * * @param program The plan to generate the optimizer representation for. * @return The optimizer representation of the plan, as a collection of all data sinks * from the plan can be traversed. */ public static List<DataSinkNode> createPreOptimizedPlan(Plan program) { GraphCreatingVisitor graphCreator = new GraphCreatingVisitor(-1, 1); program.accept(graphCreator); return graphCreator.sinks; } // ------------------------------------------------------------------------ // Visitors for Compilation Traversals // ------------------------------------------------------------------------ /** * This utility class performs the translation from the user specified program to the optimizer plan. * It works as a visitor that walks the user's job in a depth-first fashion. During the descend, it creates * an optimizer node for each operator, respectively data source or -sink. During the ascend, it connects * the nodes to the full graph. * <p> * This translator relies on the <code>setInputs</code> method in the nodes. As that method implements the size * estimation and the awareness for optimizer hints, the sizes will be properly estimated and the translated plan * already respects all optimizer hints. */ private static final class GraphCreatingVisitor implements Visitor<Operator<?>> { private final Map<Operator<?>, OptimizerNode> con2node; // map from the operator objects to their // corresponding optimizer nodes private final List<DataSourceNode> sources; // all data source nodes in the optimizer plan private final List<DataSinkNode> sinks; // all data sink nodes in the optimizer plan private final int maxMachines; // the maximum number of machines to use private final int defaultParallelism; // the default degree of parallelism private int numMemoryConsumers; private final GraphCreatingVisitor parent; // reference to enclosing creator, in case of a recursive translation private final boolean forceDOP; private GraphCreatingVisitor(int maxMachines, int defaultParallelism) { this(null, false, maxMachines, defaultParallelism, null); } private GraphCreatingVisitor(GraphCreatingVisitor parent, boolean forceDOP, int maxMachines, int defaultParallelism, HashMap<Operator<?>, OptimizerNode> closure) { if (closure == null) { con2node = new HashMap<Operator<?>, OptimizerNode>(); } else { con2node = closure; } this.sources = new ArrayList<DataSourceNode>(4); this.sinks = new ArrayList<DataSinkNode>(2); this.maxMachines = maxMachines; this.defaultParallelism = defaultParallelism; this.parent = parent; this.forceDOP = forceDOP; } @Override public boolean preVisit(Operator<?> c) { // check if we have been here before if (this.con2node.containsKey(c)) { return false; } final OptimizerNode n; // create a node for the operator (or sink or source) if we have not been here before if (c instanceof GenericDataSinkBase) { DataSinkNode dsn = new DataSinkNode((GenericDataSinkBase<?>) c); this.sinks.add(dsn); n = dsn; } else if (c instanceof GenericDataSourceBase) { DataSourceNode dsn = new DataSourceNode((GenericDataSourceBase<?, ?>) c); this.sources.add(dsn); n = dsn; } else if (c instanceof MapOperatorBase) { n = new MapNode((MapOperatorBase<?, ?, ?>) c); } else if (c instanceof CollectorMapOperatorBase) { n = new CollectorMapNode((CollectorMapOperatorBase<?, ?, ?>) c); } else if (c instanceof FlatMapOperatorBase) { n = new FlatMapNode((FlatMapOperatorBase<?, ?, ?>) c); } else if (c instanceof FilterOperatorBase) { n = new FilterNode((FilterOperatorBase<?, ?>) c); } else if (c instanceof ReduceOperatorBase) { n = new ReduceNode((ReduceOperatorBase<?, ?>) c); } else if (c instanceof GroupReduceOperatorBase) { n = new GroupReduceNode((GroupReduceOperatorBase<?, ?, ?>) c); } else if (c instanceof JoinOperatorBase) { n = new MatchNode((JoinOperatorBase<?, ?, ?, ?>) c); } else if (c instanceof CoGroupOperatorBase) { n = new CoGroupNode((CoGroupOperatorBase<?, ?, ?, ?>) c); } else if (c instanceof CrossOperatorBase) { n = new CrossNode((CrossOperatorBase<?, ?, ?, ?>) c); } else if (c instanceof BulkIterationBase) { n = new BulkIterationNode((BulkIterationBase<?>) c); } else if (c instanceof DeltaIterationBase) { n = new WorksetIterationNode((DeltaIterationBase<?, ?>) c); } else if (c instanceof Union) { n = new BinaryUnionNode((Union<?>) c); } else if (c instanceof PartialSolutionPlaceHolder) { final PartialSolutionPlaceHolder<?> holder = (PartialSolutionPlaceHolder<?>) c; final BulkIterationBase<?> enclosingIteration = holder.getContainingBulkIteration(); final BulkIterationNode containingIterationNode = (BulkIterationNode) this.parent.con2node .get(enclosingIteration); // catch this for the recursive translation of step functions BulkPartialSolutionNode p = new BulkPartialSolutionNode(holder, containingIterationNode); p.setDegreeOfParallelism(containingIterationNode.getDegreeOfParallelism()); p.setSubtasksPerInstance(containingIterationNode.getSubtasksPerInstance()); n = p; } else if (c instanceof WorksetPlaceHolder) { final WorksetPlaceHolder<?> holder = (WorksetPlaceHolder<?>) c; final DeltaIterationBase<?, ?> enclosingIteration = holder.getContainingWorksetIteration(); final WorksetIterationNode containingIterationNode = (WorksetIterationNode) this.parent.con2node .get(enclosingIteration); // catch this for the recursive translation of step functions WorksetNode p = new WorksetNode(holder, containingIterationNode); p.setDegreeOfParallelism(containingIterationNode.getDegreeOfParallelism()); p.setSubtasksPerInstance(containingIterationNode.getSubtasksPerInstance()); n = p; } else if (c instanceof SolutionSetPlaceHolder) { final SolutionSetPlaceHolder<?> holder = (SolutionSetPlaceHolder<?>) c; final DeltaIterationBase<?, ?> enclosingIteration = holder.getContainingWorksetIteration(); final WorksetIterationNode containingIterationNode = (WorksetIterationNode) this.parent.con2node .get(enclosingIteration); // catch this for the recursive translation of step functions SolutionSetNode p = new SolutionSetNode(holder, containingIterationNode); p.setDegreeOfParallelism(containingIterationNode.getDegreeOfParallelism()); p.setSubtasksPerInstance(containingIterationNode.getSubtasksPerInstance()); n = p; } else { throw new IllegalArgumentException("Unknown operator type: " + c.getClass() + " " + c); } this.con2node.put(c, n); // record the potential memory consumption this.numMemoryConsumers += n.isMemoryConsumer() ? 1 : 0; // set the parallelism only if it has not been set before. some nodes have a fixed DOP, such as the // key-less reducer (all-reduce) if (n.getDegreeOfParallelism() < 1) { // set the degree of parallelism int par = c.getDegreeOfParallelism(); if (par > 0) { if (this.forceDOP && par != this.defaultParallelism) { par = this.defaultParallelism; LOG.warn( "The degree-of-parallelism of nested Dataflows (such as step functions in iterations) is " + "currently fixed to the degree-of-parallelism of the surrounding operator (the iteration)."); } } else { par = this.defaultParallelism; } n.setDegreeOfParallelism(par); } // check if we need to set the instance sharing accordingly such that // the maximum number of machines is not exceeded if (n.getSubtasksPerInstance() < 1) { int tasksPerInstance = 1; if (this.maxMachines > 0) { int p = n.getDegreeOfParallelism(); tasksPerInstance = (p / this.maxMachines) + (p % this.maxMachines == 0 ? 0 : 1); } // we group together n tasks per machine, depending on config and the above computed // value required to obey the maximum number of machines n.setSubtasksPerInstance(tasksPerInstance); } return true; } @Override public void postVisit(Operator<?> c) { OptimizerNode n = this.con2node.get(c); // first connect to the predecessors n.setInput(this.con2node); n.setBroadcastInputs(this.con2node); // if the node represents a bulk iteration, we recursively translate the data flow now if (n instanceof BulkIterationNode) { final BulkIterationNode iterNode = (BulkIterationNode) n; final BulkIterationBase<?> iter = iterNode.getIterationContract(); // calculate closure of the anonymous function HashMap<Operator<?>, OptimizerNode> closure = new HashMap<Operator<?>, OptimizerNode>(con2node); // first, recursively build the data flow for the step function final GraphCreatingVisitor recursiveCreator = new GraphCreatingVisitor(this, true, this.maxMachines, iterNode.getDegreeOfParallelism(), closure); BulkPartialSolutionNode partialSolution = null; iter.getNextPartialSolution().accept(recursiveCreator); partialSolution = (BulkPartialSolutionNode) recursiveCreator.con2node .get(iter.getPartialSolution()); OptimizerNode rootOfStepFunction = recursiveCreator.con2node.get(iter.getNextPartialSolution()); if (partialSolution == null) { throw new CompilerException( "Error: The step functions result does not depend on the partial solution."); } OptimizerNode terminationCriterion = null; if (iter.getTerminationCriterion() != null) { terminationCriterion = recursiveCreator.con2node.get(iter.getTerminationCriterion()); // no intermediate node yet, traverse from the termination criterion to build the missing parts if (terminationCriterion == null) { iter.getTerminationCriterion().accept(recursiveCreator); terminationCriterion = recursiveCreator.con2node.get(iter.getTerminationCriterion()); } } iterNode.setNextPartialSolution(rootOfStepFunction, terminationCriterion); iterNode.setPartialSolution(partialSolution); // account for the nested memory consumers this.numMemoryConsumers += recursiveCreator.numMemoryConsumers; // go over the contained data flow and mark the dynamic path nodes StaticDynamicPathIdentifier identifier = new StaticDynamicPathIdentifier(iterNode.getCostWeight()); rootOfStepFunction.accept(identifier); if (terminationCriterion != null) { terminationCriterion.accept(identifier); } } else if (n instanceof WorksetIterationNode) { final WorksetIterationNode iterNode = (WorksetIterationNode) n; final DeltaIterationBase<?, ?> iter = iterNode.getIterationContract(); // calculate the closure of the anonymous function HashMap<Operator<?>, OptimizerNode> closure = new HashMap<Operator<?>, OptimizerNode>(con2node); // first, recursively build the data flow for the step function final GraphCreatingVisitor recursiveCreator = new GraphCreatingVisitor(this, true, this.maxMachines, iterNode.getDegreeOfParallelism(), closure); // descend from the solution set delta. check that it depends on both the workset // and the solution set. If it does depend on both, this descend should create both nodes iter.getSolutionSetDelta().accept(recursiveCreator); final SolutionSetNode solutionSetNode = (SolutionSetNode) recursiveCreator.con2node .get(iter.getSolutionSet()); final WorksetNode worksetNode = (WorksetNode) recursiveCreator.con2node.get(iter.getWorkset()); if (worksetNode == null) { throw new CompilerException( "In the given plan, the solution set delta does not depend on the workset. This is a prerequisite in workset iterations."); } iter.getNextWorkset().accept(recursiveCreator); if (solutionSetNode == null || solutionSetNode.getOutgoingConnections() == null || solutionSetNode.getOutgoingConnections().isEmpty()) { throw new CompilerException("Error: The step function does not reference the solution set."); } else { for (PactConnection conn : solutionSetNode.getOutgoingConnections()) { OptimizerNode successor = conn.getTarget(); if (successor.getClass() == MatchNode.class) { // find out which input to the match the solution set is MatchNode mn = (MatchNode) successor; if (mn.getFirstPredecessorNode() == solutionSetNode) { mn.makeJoinWithSolutionSet(0); } else if (mn.getSecondPredecessorNode() == solutionSetNode) { mn.makeJoinWithSolutionSet(1); } else { throw new CompilerException(); } } else if (successor.getClass() == CoGroupNode.class) { CoGroupNode cg = (CoGroupNode) successor; if (cg.getFirstPredecessorNode() == solutionSetNode) { cg.makeCoGroupWithSolutionSet(0); } else if (cg.getSecondPredecessorNode() == solutionSetNode) { cg.makeCoGroupWithSolutionSet(1); } else { throw new CompilerException(); } } else { throw new CompilerException( "Error: The solution set may only be joined with through a Join or a CoGroup function."); } } } final OptimizerNode nextWorksetNode = recursiveCreator.con2node.get(iter.getNextWorkset()); final OptimizerNode solutionSetDeltaNode = recursiveCreator.con2node .get(iter.getSolutionSetDelta()); // set the step function nodes to the iteration node iterNode.setPartialSolution(solutionSetNode, worksetNode); iterNode.setNextPartialSolution(solutionSetDeltaNode, nextWorksetNode); // account for the nested memory consumers this.numMemoryConsumers += recursiveCreator.numMemoryConsumers; // go over the contained data flow and mark the dynamic path nodes StaticDynamicPathIdentifier pathIdentifier = new StaticDynamicPathIdentifier( iterNode.getCostWeight()); nextWorksetNode.accept(pathIdentifier); iterNode.getSolutionSetDelta().accept(pathIdentifier); } } int getMemoryConsumerCount() { return this.numMemoryConsumers; } }; private static final class StaticDynamicPathIdentifier implements Visitor<OptimizerNode> { private final Set<OptimizerNode> seenBefore = new HashSet<OptimizerNode>(); private final int costWeight; private StaticDynamicPathIdentifier(int costWeight) { this.costWeight = costWeight; } @Override public boolean preVisit(OptimizerNode visitable) { return this.seenBefore.add(visitable); } @Override public void postVisit(OptimizerNode visitable) { visitable.identifyDynamicPath(this.costWeight); } } /** * Simple visitor that sets the minimal guaranteed memory per task based on the amount of available memory, * the number of memory consumers, and on the task's degree of parallelism. */ private static final class IdAndMemoryAndEstimatesVisitor implements Visitor<OptimizerNode> { private final DataStatistics statistics; private final long memoryPerTaskPerInstance; private int id = 1; private IdAndMemoryAndEstimatesVisitor(DataStatistics statistics, long memoryPerTaskPerInstance) { this.statistics = statistics; this.memoryPerTaskPerInstance = memoryPerTaskPerInstance; } @Override public boolean preVisit(OptimizerNode visitable) { if (visitable.getId() != -1) { // been here before return false; } // assign minimum memory share, for lower bound estimates final long mem = visitable.isMemoryConsumer() ? this.memoryPerTaskPerInstance / visitable.getSubtasksPerInstance() : 0; visitable.setMinimalMemoryPerSubTask(mem); return true; } @Override public void postVisit(OptimizerNode visitable) { // the node ids visitable.initId(this.id++); // connections need to figure out their maximum path depths for (PactConnection conn : visitable.getIncomingConnections()) { conn.initMaxDepth(); } for (PactConnection conn : visitable.getBroadcastConnections()) { conn.initMaxDepth(); } // the estimates visitable.computeOutputEstimates(this.statistics); // if required, recurse into the step function if (visitable instanceof IterationNode) { ((IterationNode) visitable).acceptForStepFunction(this); } } } /** * Visitor that computes the interesting properties for each node in the plan. On its recursive * depth-first descend, it propagates all interesting properties top-down. */ public static final class InterestingPropertyVisitor implements Visitor<OptimizerNode> { private CostEstimator estimator; // the cost estimator for maximal costs of an interesting property /** * Creates a new visitor that computes the interesting properties for all nodes in the plan. * It uses the given cost estimator used to compute the maximal costs for an interesting property. * * @param estimator * The cost estimator to estimate the maximal costs for interesting properties. */ public InterestingPropertyVisitor(CostEstimator estimator) { this.estimator = estimator; } @Override public boolean preVisit(OptimizerNode node) { // The interesting properties must be computed on the descend. In case a node has multiple outputs, // that computation must happen during the last descend. if (node.getInterestingProperties() == null && node.haveAllOutputConnectionInterestingProperties()) { node.computeUnionOfInterestingPropertiesFromSuccessors(); node.computeInterestingPropertiesForInputs(this.estimator); return true; } else { return false; } } @Override public void postVisit(OptimizerNode visitable) { } } /** * On its re-ascend (post visit) this visitor, computes auxiliary maps that are needed to support plans * that are not a minimally connected DAG (Such plans are not trees, but at least one node feeds its * output into more than one other node). */ private static final class BranchesVisitor implements Visitor<OptimizerNode> { @Override public boolean preVisit(OptimizerNode node) { return node.getOpenBranches() == null; } @Override public void postVisit(OptimizerNode node) { if (node instanceof IterationNode) { ((IterationNode) node).acceptForStepFunction(this); } node.computeUnclosedBranchStack(); } }; /** * Utility class that traverses a plan to collect all nodes and add them to the OptimizedPlan. * Besides collecting all nodes, this traversal assigns the memory to the nodes. */ private static final class PlanFinalizer implements Visitor<PlanNode> { private final Set<PlanNode> allNodes; // a set of all nodes in the optimizer plan private final List<SourcePlanNode> sources; // all data source nodes in the optimizer plan private final List<SinkPlanNode> sinks; // all data sink nodes in the optimizer plan private final Deque<IterationPlanNode> stackOfIterationNodes; private long memoryPerInstance; // the amount of memory per instance private int memoryConsumerWeights; // a counter of all memory consumers /** * Creates a new plan finalizer. */ private PlanFinalizer() { this.allNodes = new HashSet<PlanNode>(); this.sources = new ArrayList<SourcePlanNode>(); this.sinks = new ArrayList<SinkPlanNode>(); this.stackOfIterationNodes = new ArrayDeque<IterationPlanNode>(); } private OptimizedPlan createFinalPlan(List<SinkPlanNode> sinks, String jobName, Plan originalPlan, long memPerInstance) { if (LOG.isDebugEnabled()) { LOG.debug("Available memory per instance: " + memPerInstance); } this.memoryPerInstance = memPerInstance; this.memoryConsumerWeights = 0; // traverse the graph for (SinkPlanNode node : sinks) { node.accept(this); } // assign the memory to each node if (this.memoryConsumerWeights > 0) { final long memoryPerInstanceAndWeight = this.memoryPerInstance / this.memoryConsumerWeights; if (LOG.isDebugEnabled()) { LOG.debug("Memory per consumer weight: " + memoryPerInstanceAndWeight); } for (PlanNode node : this.allNodes) { // assign memory to the driver strategy of the node final int consumerWeight = node.getMemoryConsumerWeight(); if (consumerWeight > 0) { final long mem = memoryPerInstanceAndWeight * consumerWeight / node.getSubtasksPerInstance(); node.setMemoryPerSubTask(mem); if (LOG.isDebugEnabled()) { final long mib = mem >> 20; LOG.debug("Assigned " + mib + " MiBytes memory to each subtask of " + node.getPactContract().getName() + " (" + mib * node.getDegreeOfParallelism() + " MiBytes total.)"); } } // assign memory to the local and global strategies of the channels for (Iterator<Channel> channels = node.getInputs(); channels.hasNext();) { final Channel c = channels.next(); if (c.getLocalStrategy().dams()) { final long mem = memoryPerInstanceAndWeight / node.getSubtasksPerInstance(); c.setMemoryLocalStrategy(mem); if (LOG.isDebugEnabled()) { final long mib = mem >> 20; LOG.debug("Assigned " + mib + " MiBytes memory to each local strategy instance of " + c + " (" + mib * node.getDegreeOfParallelism() + " MiBytes total.)"); } } if (c.getTempMode() != TempMode.NONE) { final long mem = memoryPerInstanceAndWeight / node.getSubtasksPerInstance(); c.setTempMemory(mem); if (LOG.isDebugEnabled()) { final long mib = mem >> 20; LOG.debug("Assigned " + mib + " MiBytes memory to each instance of the temp table for " + c + " (" + mib * node.getDegreeOfParallelism() + " MiBytes total.)"); } } } } } return new OptimizedPlan(this.sources, this.sinks, this.allNodes, jobName, originalPlan); } @Override public boolean preVisit(PlanNode visitable) { // if we come here again, prevent a further descend if (!this.allNodes.add(visitable)) { return false; } if (visitable instanceof SinkPlanNode) { this.sinks.add((SinkPlanNode) visitable); } else if (visitable instanceof SourcePlanNode) { this.sources.add((SourcePlanNode) visitable); } else if (visitable instanceof BulkPartialSolutionPlanNode) { // tell the partial solution about the iteration node that contains it final BulkPartialSolutionPlanNode pspn = (BulkPartialSolutionPlanNode) visitable; final IterationPlanNode iteration = this.stackOfIterationNodes.peekLast(); // sanity check! if (iteration == null || !(iteration instanceof BulkIterationPlanNode)) { throw new CompilerException("Bug: Error finalizing the plan. " + "Cannot associate the node for a partial solutions with its containing iteration."); } pspn.setContainingIterationNode((BulkIterationPlanNode) iteration); } else if (visitable instanceof WorksetPlanNode) { // tell the partial solution about the iteration node that contains it final WorksetPlanNode wspn = (WorksetPlanNode) visitable; final IterationPlanNode iteration = this.stackOfIterationNodes.peekLast(); // sanity check! if (iteration == null || !(iteration instanceof WorksetIterationPlanNode)) { throw new CompilerException("Bug: Error finalizing the plan. " + "Cannot associate the node for a partial solutions with its containing iteration."); } wspn.setContainingIterationNode((WorksetIterationPlanNode) iteration); } else if (visitable instanceof SolutionSetPlanNode) { // tell the partial solution about the iteration node that contains it final SolutionSetPlanNode sspn = (SolutionSetPlanNode) visitable; final IterationPlanNode iteration = this.stackOfIterationNodes.peekLast(); // sanity check! if (iteration == null || !(iteration instanceof WorksetIterationPlanNode)) { throw new CompilerException("Bug: Error finalizing the plan. " + "Cannot associate the node for a partial solutions with its containing iteration."); } sspn.setContainingIterationNode((WorksetIterationPlanNode) iteration); } // double-connect the connections. previously, only parents knew their children, because // one child candidate could have been referenced by multiple parents. for (Iterator<Channel> iter = visitable.getInputs(); iter.hasNext();) { final Channel conn = iter.next(); conn.setTarget(visitable); conn.getSource().addOutgoingChannel(conn); } for (Channel c : visitable.getBroadcastInputs()) { c.setTarget(visitable); c.getSource().addOutgoingChannel(c); } // count the memory consumption this.memoryConsumerWeights += visitable.getMemoryConsumerWeight(); for (Iterator<Channel> channels = visitable.getInputs(); channels.hasNext();) { final Channel c = channels.next(); if (c.getLocalStrategy().dams()) { this.memoryConsumerWeights++; } if (c.getTempMode() != TempMode.NONE) { this.memoryConsumerWeights++; } } for (Channel c : visitable.getBroadcastInputs()) { if (c.getLocalStrategy().dams()) { this.memoryConsumerWeights++; } if (c.getTempMode() != TempMode.NONE) { this.memoryConsumerWeights++; } } // pass the visitor to the iteraton's step function if (visitable instanceof IterationPlanNode) { // push the iteration node onto the stack final IterationPlanNode iterNode = (IterationPlanNode) visitable; this.stackOfIterationNodes.addLast(iterNode); // recurse ((IterationPlanNode) visitable).acceptForStepFunction(this); // pop the iteration node from the stack this.stackOfIterationNodes.removeLast(); } return true; } @Override public void postVisit(PlanNode visitable) { } } /** * A visitor that traverses the graph and collects cascading binary unions into a single n-ary * union operator. The exception is, when on of the union inputs is materialized, such as in the * static-code-path-cache in iterations. */ private static final class BinaryUnionReplacer implements Visitor<PlanNode> { private final Set<PlanNode> seenBefore = new HashSet<PlanNode>(); @Override public boolean preVisit(PlanNode visitable) { if (this.seenBefore.add(visitable)) { if (visitable instanceof IterationPlanNode) { ((IterationPlanNode) visitable).acceptForStepFunction(this); } return true; } else { return false; } } @Override public void postVisit(PlanNode visitable) { if (visitable instanceof BinaryUnionPlanNode) { final BinaryUnionPlanNode unionNode = (BinaryUnionPlanNode) visitable; final Channel in1 = unionNode.getInput1(); final Channel in2 = unionNode.getInput2(); PlanNode newUnionNode; // if any input is cached, we keep this as a binary union and do not collapse it into a // n-ary union // if (in1.getTempMode().isCached() || in2.getTempMode().isCached()) { // // replace this node by an explicit operator // Channel cached, pipelined; // if (in1.getTempMode().isCached()) { // cached = in1; // pipelined = in2; // } else { // cached = in2; // pipelined = in1; // } // // newUnionNode = new DualInputPlanNode(unionNode.getOriginalOptimizerNode(), cached, pipelined, // DriverStrategy.UNION_WITH_CACHED); // newUnionNode.initProperties(unionNode.getGlobalProperties(), new LocalProperties()); // // in1.setTarget(newUnionNode); // in2.setTarget(newUnionNode); // } else { // collect the union inputs to collapse this operator with // its collapsed predecessors. check whether an input is materialized to prevent // collapsing List<Channel> inputs = new ArrayList<Channel>(); collect(in1, inputs); collect(in2, inputs); newUnionNode = new NAryUnionPlanNode(unionNode.getOptimizerNode(), inputs, unionNode.getGlobalProperties()); // adjust the input channels to have their target point to the new union node for (Channel c : inputs) { c.setTarget(newUnionNode); } // } unionNode.getOutgoingChannels().get(0).swapUnionNodes(newUnionNode); } } private void collect(Channel in, List<Channel> inputs) { if (in.getSource() instanceof NAryUnionPlanNode) { // sanity check if (in.getShipStrategy() != ShipStrategyType.FORWARD) { throw new CompilerException( "Bug: Plan generation for Unions picked a ship strategy between binary plan operators."); } if (!(in.getLocalStrategy() == null || in.getLocalStrategy() == LocalStrategy.NONE)) { throw new CompilerException( "Bug: Plan generation for Unions picked a local strategy between binary plan operators."); } inputs.addAll(((NAryUnionPlanNode) in.getSource()).getListOfInputs()); } else { // is not a union node, so we take the channel directly inputs.add(in); } } } // ------------------------------------------------------------------------ // Miscellaneous // ------------------------------------------------------------------------ private OptimizerPostPass getPostPassFromPlan(Plan program) { final String className = program.getPostPassClassName(); if (className == null) { throw new CompilerException("Optimizer Post Pass class description is null"); } try { Class<? extends OptimizerPostPass> clazz = Class.forName(className).asSubclass(OptimizerPostPass.class); try { return InstantiationUtil.instantiate(clazz, OptimizerPostPass.class); } catch (RuntimeException rtex) { // unwrap the source exception if (rtex.getCause() != null) { throw new CompilerException("Cannot instantiate optimizer post pass: " + rtex.getMessage(), rtex.getCause()); } else { throw rtex; } } } catch (ClassNotFoundException cnfex) { throw new CompilerException("Cannot load Optimizer post-pass class '" + className + "'.", cnfex); } catch (ClassCastException ccex) { throw new CompilerException("Class '" + className + "' is not an optimizer post passer.", ccex); } } private InstanceTypeDescription getInstanceTypeInfo() { if (LOG.isDebugEnabled()) { LOG.debug("Connecting compiler to JobManager to dertermine instance information."); } // create the connection in a separate thread, such that this thread // can abort, if an unsuccessful connection occurs. Map<InstanceType, InstanceTypeDescription> instances = null; JobManagerConnector jmc = new JobManagerConnector(this.jobManagerAddress); Thread connectorThread = new Thread(jmc, "Compiler - JobManager connector."); connectorThread.setDaemon(true); connectorThread.start(); // connect and get the result try { jmc.waitForCompletion(); instances = jmc.instances; if (instances == null) { throw new NullPointerException("Returned instance map is <null>"); } } catch (IOException e) { throw new CompilerException(e.getMessage()); } catch (Throwable t) { throw new CompilerException("Cannot connect to the JobManager to determine the available TaskManagers. " + "Check if the JobManager is running (using the web interface or log files). Reason: " + t.getMessage(), t); } // determine which type to run on return getType(instances); } /** * This utility method picks the instance type to be used for executing programs. * <p> * * @param types The available types. * @return The type to be used for scheduling. * * @throws CompilerException * @throws IllegalArgumentException */ private InstanceTypeDescription getType(Map<InstanceType, InstanceTypeDescription> types) throws CompilerException { if (types == null || types.size() < 1) { throw new IllegalArgumentException("No instance type found."); } InstanceTypeDescription retValue = null; long totalMemory = 0; int numInstances = 0; final Iterator<InstanceTypeDescription> it = types.values().iterator(); while (it.hasNext()) { final InstanceTypeDescription descr = it.next(); // skip instances for which no hardware description is available // this means typically that no if (descr.getHardwareDescription() == null || descr.getInstanceType() == null) { continue; } final int curInstances = descr.getMaximumNumberOfAvailableInstances(); final long curMemory = curInstances * descr.getHardwareDescription().getSizeOfFreeMemory(); // get, if first, or if it has more instances and not less memory, or if it has significantly more memory // and the same number of cores still if ((retValue == null) || (curInstances > numInstances && (int) (curMemory * 1.2f) > totalMemory) || (curInstances * retValue.getInstanceType().getNumberOfCores() >= numInstances && (int) (curMemory * 1.5f) > totalMemory)) { retValue = descr; numInstances = curInstances; totalMemory = curMemory; } } if (retValue == null) { throw new CompilerException("No instance currently registered at the job-manager. Retry later.\n" + "If the system has recently started, it may take a few seconds until the instances register."); } return retValue; } /** * Utility class for an asynchronous connection to the job manager to determine the available instances. */ private static final class JobManagerConnector implements Runnable { private static final long MAX_MILLIS_TO_WAIT = 10000; private final InetSocketAddress jobManagerAddress; private final Object lock = new Object(); private volatile Map<InstanceType, InstanceTypeDescription> instances; private volatile Throwable error; private JobManagerConnector(InetSocketAddress jobManagerAddress) { this.jobManagerAddress = jobManagerAddress; } public Map<InstanceType, InstanceTypeDescription> waitForCompletion() throws Throwable { long start = System.currentTimeMillis(); long remaining = MAX_MILLIS_TO_WAIT; if (this.error != null) { throw this.error; } if (this.instances != null) { return this.instances; } do { try { synchronized (this.lock) { this.lock.wait(remaining); } } catch (InterruptedException iex) { } } while (this.error == null && this.instances == null && (remaining = MAX_MILLIS_TO_WAIT + start - System.currentTimeMillis()) > 0); if (this.error != null) { throw this.error; } if (this.instances != null) { return this.instances; } throw new IOException("Could not connect to the JobManager at " + jobManagerAddress + ". Please make sure that the Job Manager is started properly."); } @Override public void run() { ExtendedManagementProtocol jobManagerConnection = null; try { jobManagerConnection = RPC.getProxy(ExtendedManagementProtocol.class, this.jobManagerAddress, NetUtils.getSocketFactory()); this.instances = jobManagerConnection.getMapOfAvailableInstanceTypes(); if (this.instances == null) { throw new IOException("Returned instance map was <null>"); } } catch (Throwable t) { this.error = t; } finally { // first of all, signal completion synchronized (this.lock) { this.lock.notifyAll(); } if (jobManagerConnection != null) { try { RPC.stopProxy(jobManagerConnection); } catch (Throwable t) { LOG.error("Could not cleanly shut down connection from compiler to job manager,", t); } } jobManagerConnection = null; } } } }