org.javades.jqueues.r5.util.predictor

Interface SimQueuePredictor<Q extends SimQueue>

Type Parameters:

Q - The type of SimQueues supported.

All Superinterfaces:

SimQueueEventPredictor<Q>, SimQueueStatePredictor<Q>

All Known Implementing Classes:

AbstractSimQueuePredictor, AbstractSimQueuePredictor_Composite, AbstractSimQueuePredictor_Composite_Enc, AbstractSimQueuePredictor_Composite_LocalStart, SimQueuePredictor_ALIMIT, SimQueuePredictor_CTandem2, SimQueuePredictor_CUPS, SimQueuePredictor_DELAY, SimQueuePredictor_DLIMIT, SimQueuePredictor_DROP, SimQueuePredictor_Enc, SimQueuePredictor_EncHS, SimQueuePredictor_EncJL, SimQueuePredictor_EncTL, SimQueuePredictor_FB_v, SimQueuePredictor_FCFS, SimQueuePredictor_FCFS_B, SimQueuePredictor_FCFS_B_c, SimQueuePredictor_FCFS_c, SimQueuePredictor_GATE, SimQueuePredictor_HOL, SimQueuePredictor_HOL_PS, SimQueuePredictor_IC, SimQueuePredictor_IS, SimQueuePredictor_IS_CST, SimQueuePredictor_LCFS, SimQueuePredictor_LCFS_B, SimQueuePredictor_LeakyBucket, SimQueuePredictor_LJF, SimQueuePredictor_NoBuffer_c, SimQueuePredictor_P_LCFS, SimQueuePredictor_Pattern, SimQueuePredictor_PQ, SimQueuePredictor_Preemptive, SimQueuePredictor_PS, SimQueuePredictor_SINK, SimQueuePredictor_SJF, SimQueuePredictor_SocPS, SimQueuePredictor_SRTF, SimQueuePredictor_SUR, SimQueuePredictor_Tandem, SimQueuePredictor_WUR, SimQueuePredictor_ZERO

public interface SimQueuePredictor<Q extends SimQueue>
extends SimQueueEventPredictor<Q>, SimQueueStatePredictor<Q>

An object capable of predicting the behavior of one or more SimQueues under user-supplied workload and conditions.

A SimQueuePredictor is a stateless object that is capable of predicting the behavior of a specific SimQueue class or (if applicable) of (some of) its subclasses; the (base) class of queues supported is present as generic type argument Q. Objects like this are extensively used in the test sub-system of jqueues.

The most important feature of a SimQueuePredictor is the prediction of job visits to a given (stateless!) SimQueue under a given external workload (e.g., arrivals, revocations, setting server-access credits, or queue-specific external operations). The workload consists of a collection of SimJQEvents, and this collection may contain events scheduled at the same time. Depending on the method invoked on the predictor, such simultaneous events are to be interpreted as occurring in "random order" (as if processed by a ROEL SimEventList like DefaultSimEventList_ROEL) or as occurring in the strict and deterministic order (somehow) imposed by the collection (as if processed by a IOEL SimEventList like DefaultSimEventList_IOEL).

In the first case, see predict_SQ_SV_ROEL_U(Q, java.util.Set<org.javades.jqueues.r5.entity.jq.SimJQEvent>), the workload schedule itself can easily lead to ambiguities that prevent the delivery of a prediction, for instance in the case of simultaneous arrivals (of jobs with non-zero required service time) at a FCFS queue. On the other hand, queues like ZERO appear to be robust against simultaneous arrivals under ROEL, and for queues like IC, simultaneous arrivals under ROEL are unambiguous only if sufficient server-access credits are available, hence, the ambiguity of simultaneous arrivals for this queue is state-dependent. However, for all SimQueues, the simultaneous start of a queue-access vacation (again, state-dependent) and an arrival always leads to ambiguities.

In the seconds case, see predict_SQ_SV_IOEL_U(Q, java.util.NavigableMap<java.lang.Double, java.util.Set<org.javades.jqueues.r5.entity.jq.SimJQEvent>>, java.util.NavigableMap<java.lang.Double, java.util.Set<org.javades.jqueues.r5.entity.jq.SimJQEvent>>), workload events do not cause ambiguities among themselves, but they may still interfere with queue-internal events like departures, for instance the simultaneous occurrence of an arrival and a scheduled departure in a P_LCFS queue that is otherwise empty. Even worse, queues may exhibit internal ambiguities, for instance, the simultaneous occurrence of a "catch-up" and a departure (both "internal events") in a CUPS queue. Note that even with a ROEL SimEventList, certain SimQueue implementations may process "simultaneous events" in a specific sequence, and heavily rely on their sequential execution. For instance, the Tandem lets (delegate) jobs arrive at their first sub-queue if server-access credits become available, yet it processes these arrivals in a specific order (the arrival order of the corresponding "real" jobs) and it effectuates these arrivals immediately, without using the underlying event list.

In any case, implementations must provide a collection of visit logs, see JobQueueVisitLog, or throw an exception upon determining an ambiguity, see SimQueuePredictionAmbiguityException.

Author:

Jan de Jongh, TNO

Copyright (C) 2005-2017 Jan de Jongh, TNO

This file is covered by the LICENSE file in the root of this project.

Method Summary

Modifier and Type	Method and Description
static <Q extends SimQueue> boolean	matchVisitLogs_SQ_SV(Q queue, Map<SimJob,JobQueueVisitLog<SimJob,Q>> predicted, Map<SimJob,TreeMap<Double,TreeMap<Integer,JobQueueVisitLog<SimJob,Q>>>> actual, double accuracy, PrintStream stream, String testString) Compares two maps of predicted and actual JobQueueVisitLogs for equality, within given accuracy.
SimQueuePrediction_SQ_SV<Q>	predict_SQ_SV_IOEL_U(Q queue, NavigableMap<Double,Set<SimJQEvent>> workloadEventsMap, NavigableMap<Double,Set<SimJQEvent>> processedEventsMap) Creates the unique prediction, if possible, resulting from subjecting a given queue to a given workload under an Insertion-Order Event List.
SimQueuePrediction_SQ_SV<Q>	predict_SQ_SV_ROEL_U(Q queue, Set<SimJQEvent> workloadEvents) Creates the unique prediction, if possible, resulting from subjecting a given queue to a given workload under a Random-Order Event List.

Methods inherited from interface org.javades.jqueues.r5.util.predictor.SimQueueEventPredictor

createQueueState, createWorkloadSchedule_SQ_SV_ROEL_U, createWorkloadSchedule_SQ_SV, doQueueEvents_SQ_SV_ROEL_U, doWorkloadEvents_SQ_SV_ROEL_U, doWorkloadEvents_SQ_SV, getNextQueueEventTimeBeyond, updateToTime

Methods inherited from interface org.javades.jqueues.r5.util.predictor.SimQueueStatePredictor

hasServerAccessCredits, isQueueAccessVacation, isStartArmed

Method Detail

predict_SQ_SV_ROEL_U

SimQueuePrediction_SQ_SV<Q> predict_SQ_SV_ROEL_U(Q queue,
                                                 Set<SimJQEvent> workloadEvents)
                                          throws SimQueuePredictionException

Creates the unique prediction, if possible, resulting from subjecting a given queue to a given workload under a Random-Order Event List.

Parameters:

queue - The queue, non-null.

workloadEvents - The workload events; events related to other queues are allowed and are to be ignored.

Returns:

The prediction.

Throws:

IllegalArgumentException - If queue == null or the workload parameters are somehow illegal.

UnsupportedOperationException - If the queue type or the workload is (partially) unsupported.

SimQueuePredictionException - If a prediction is (e.g.) too complex to generate (SimQueuePredictionComplexityException), if invalid input has been supplied to the predictor (SimQueuePredictionInvalidInputException), or if a unique prediction cannot be generated (SimQueuePredictionAmbiguityException).

predict_SQ_SV_IOEL_U

SimQueuePrediction_SQ_SV<Q> predict_SQ_SV_IOEL_U(Q queue,
                                                 NavigableMap<Double,Set<SimJQEvent>> workloadEventsMap,
                                                 NavigableMap<Double,Set<SimJQEvent>> processedEventsMap)
                                          throws SimQueuePredictionException

Creates the unique prediction, if possible, resulting from subjecting a given queue to a given workload under an Insertion-Order Event List.

Note that processed-events map parameter may be equal to the workload events map, in which case processed (internal) events are inserted in situ. If a different map is provided, it is cleared upon entry.

Parameters:

queue - The queue, non-null.

workloadEventsMap - The workload events as a map from event time onto the (ordered!) set of events occurring at that time; events related to other queues are allowed and are to be ignored.

processedEventsMap - An optional map in which all events processed at the queue (including workload events) are stored unambiguously; the events in a value set are in processing ordered (you can use this to resolve ambiguities in the visit logs like equal departure times).

Returns:

The prediction.

Throws:

IllegalArgumentException - If queue == null or the workload parameters are somehow illegal.

UnsupportedOperationException - If the queue type or the workload is (partially) unsupported.

SimQueuePredictionException - If a prediction is (e.g.) too complex to generate (SimQueuePredictionComplexityException), if invalid input has been supplied to the predictor (SimQueuePredictionInvalidInputException), or if a unique prediction cannot be generated (SimQueuePredictionAmbiguityException).

matchVisitLogs_SQ_SV

static <Q extends SimQueue> boolean matchVisitLogs_SQ_SV(Q queue,
                                                         Map<SimJob,JobQueueVisitLog<SimJob,Q>> predicted,
                                                         Map<SimJob,TreeMap<Double,TreeMap<Integer,JobQueueVisitLog<SimJob,Q>>>> actual,
                                                         double accuracy,
                                                         PrintStream stream,
                                                         String testString)

Compares two maps of predicted and actual JobQueueVisitLogs for equality, within given accuracy.

The actual argument holds all (allowing multiple) job visits, and may contain visits to other SimQueues; the latter of which are (to be) ignored. The map has the jobs as keys, and each value holds another map from arrival times (of the particular job) to numbered JobQueueVisitLog of that job at that particular arrival time (this allows multiple arrivals of the same job at the same time).

Type Parameters:

Q - The (generic) type of the queue.

Parameters:

queue - The queue, non-null.

predicted - The predicted JobQueueVisitLogs, indexed by job-arrival time; arrival at other queues are (to be) ignored.

actual - The actual JobQueueVisitLogs, see above.

accuracy - The accuracy (maximum deviation of times in a JobQueueVisitLog), non-negative.

stream - An optional stream for mismatch reporting.

testString - An optional String identifying the test in place.

Returns:

Whether the predicted and actual maps map within the given accuracy.

Throws:

IllegalArgumentException - If any of the arguments except the stream has null value, is illegally structured, or if the accuracy argument is negative.