X-Git-Url: https://gerrit.fd.io/r/gitweb?p=csit.git;a=blobdiff_plain;f=resources%2Flibraries%2Fpython%2FPLRsearch%2FPLRsearch.py;h=e20d293d3c0f8425c9a8c826c914b12e8726167e;hp=b7c93443913ae2756f07c96536bccbb3d48083b9;hb=d68951ac245150eeefa6e0f4156e4c1b5c9e9325;hpb=ed0258a440cfad7023d643f717ab78ac568dc59b diff --git a/resources/libraries/python/PLRsearch/PLRsearch.py b/resources/libraries/python/PLRsearch/PLRsearch.py index b7c9344391..e20d293d3c 100644 --- a/resources/libraries/python/PLRsearch/PLRsearch.py +++ b/resources/libraries/python/PLRsearch/PLRsearch.py @@ -17,20 +17,22 @@ import logging import math import multiprocessing import time + from collections import namedtuple import dill + from scipy.special import erfcx, erfc # TODO: Teach FD.io CSIT to use multiple dirs in PYTHONPATH, # then switch to absolute imports within PLRsearch package. # Current usage of relative imports is just a short term workaround. from . import Integrator -from .log_plus import log_plus, log_minus from . import stat_trackers +from .log_plus import log_plus, log_minus -class PLRsearch(object): +class PLRsearch: """A class to encapsulate data relevant for the search method. The context is performance testing of packet processing systems. @@ -41,7 +43,7 @@ class PLRsearch(object): Two constants are stored as class fields for speed. - Method othed than search (and than __init__) + Method other than search (and than __init__) are just internal code structure. TODO: Those method names should start with underscore then. @@ -168,20 +170,23 @@ class PLRsearch(object): stop_time = time.time() + self.timeout min_rate = float(min_rate) max_rate = float(max_rate) - logging.info("Started search with min_rate %(min)r, max_rate %(max)r", - {"min": min_rate, "max": max_rate}) + logging.info( + f"Started search with min_rate {min_rate!r}, " + f"max_rate {max_rate!r}" + ) trial_result_list = list() trial_number = self.trial_number_offset focus_trackers = (None, None) transmit_rate = (min_rate + max_rate) / 2.0 lossy_loads = [max_rate] - zeros = 0 # How many cosecutive zero loss results are happening. + zeros = 0 # How many consecutive zero loss results are happening. while 1: trial_number += 1 - logging.info("Trial %(number)r", {"number": trial_number}) + logging.info(f"Trial {trial_number!r}") results = self.measure_and_compute( self.trial_duration_per_trial * trial_number, transmit_rate, - trial_result_list, min_rate, max_rate, focus_trackers) + trial_result_list, min_rate, max_rate, focus_trackers + ) measurement, average, stdev, avg1, avg2, focus_trackers = results zeros += 1 # TODO: Ratio of fill rate to drain rate seems to have @@ -212,9 +217,10 @@ class PLRsearch(object): # in order to get to usable loses at higher loads. if len(lossy_loads) > 3: lossy_loads = lossy_loads[3:] - logging.debug("Zeros %(z)r orig %(o)r next %(n)r loads %(s)r", - {"z": zeros, "o": (avg1 + avg2) / 2.0, - "n": next_load, "s": lossy_loads}) + logging.debug( + f"Zeros {zeros!r} orig {(avg1 + avg2) / 2.0!r} " + f"next {next_load!r} loads {lossy_loads!r}" + ) transmit_rate = min(max_rate, max(min_rate, next_load)) @staticmethod @@ -255,21 +261,22 @@ class PLRsearch(object): # TODO: chi is from https://en.wikipedia.org/wiki/Nondimensionalization chi = (load - mrr) / spread chi0 = -mrr / spread - trace("stretch: load", load) - trace("mrr", mrr) - trace("spread", spread) - trace("chi", chi) - trace("chi0", chi0) + trace(u"stretch: load", load) + trace(u"mrr", mrr) + trace(u"spread", spread) + trace(u"chi", chi) + trace(u"chi0", chi0) if chi > 0: log_lps = math.log( - load - mrr + (log_plus(0, -chi) - log_plus(0, chi0)) * spread) - trace("big loss direct log_lps", log_lps) + load - mrr + (log_plus(0, -chi) - log_plus(0, chi0)) * spread + ) + trace(u"big loss direct log_lps", log_lps) else: two_positive = log_plus(chi, 2 * chi0 - log_2) two_negative = log_plus(chi0, 2 * chi - log_2) if two_positive <= two_negative: log_lps = log_minus(chi, chi0) + log_spread - trace("small loss crude log_lps", log_lps) + trace(u"small loss crude log_lps", log_lps) return log_lps two = log_minus(two_positive, two_negative) three_positive = log_plus(two_positive, 3 * chi - log_3) @@ -277,11 +284,11 @@ class PLRsearch(object): three = log_minus(three_positive, three_negative) if two == three: log_lps = two + log_spread - trace("small loss approx log_lps", log_lps) + trace(u"small loss approx log_lps", log_lps) else: log_lps = math.log(log_plus(0, chi) - log_plus(0, chi0)) log_lps += log_spread - trace("small loss direct log_lps", log_lps) + trace(u"small loss direct log_lps", log_lps) return log_lps @staticmethod @@ -320,26 +327,26 @@ class PLRsearch(object): # TODO: The stretch sign is just to have less minuses. Worth changing? chi = (mrr - load) / spread chi0 = mrr / spread - trace("Erf: load", load) - trace("mrr", mrr) - trace("spread", spread) - trace("chi", chi) - trace("chi0", chi0) + trace(u"Erf: load", load) + trace(u"mrr", mrr) + trace(u"spread", spread) + trace(u"chi", chi) + trace(u"chi0", chi0) if chi >= -1.0: - trace("positive, b roughly bigger than m", None) + trace(u"positive, b roughly bigger than m", None) if chi > math.exp(10): first = PLRsearch.log_xerfcx_10 + 2 * (math.log(chi) - 10) - trace("approximated first", first) + trace(u"approximated first", first) else: first = math.log(PLRsearch.xerfcx_limit - chi * erfcx(chi)) - trace("exact first", first) + trace(u"exact first", first) first -= chi * chi second = math.log(PLRsearch.xerfcx_limit - chi * erfcx(chi0)) second -= chi0 * chi0 intermediate = log_minus(first, second) - trace("first", first) + trace(u"first", first) else: - trace("negative, b roughly smaller than m", None) + trace(u"negative, b roughly smaller than m", None) exp_first = PLRsearch.xerfcx_limit + chi * erfcx(-chi) exp_first *= math.exp(-chi * chi) exp_first -= 2 * chi @@ -350,11 +357,11 @@ class PLRsearch(object): second = math.log(PLRsearch.xerfcx_limit - chi * erfcx(chi0)) second -= chi0 * chi0 intermediate = math.log(exp_first - math.exp(second)) - trace("exp_first", exp_first) - trace("second", second) - trace("intermediate", intermediate) + trace(u"exp_first", exp_first) + trace(u"second", second) + trace(u"intermediate", intermediate) result = intermediate + math.log(spread) - math.log(erfc(-chi0)) - trace("result", result) + trace(u"result", result) return result @staticmethod @@ -385,7 +392,7 @@ class PLRsearch(object): :type lfit_func: Function from 3 floats to float. :type min_rate: float :type max_rate: float - :type log_lps_target: float + :type loss_ratio_target: float :type mrr: float :type spread: float :returns: Load [pps] which achieves the target with given parameters. @@ -397,17 +404,17 @@ class PLRsearch(object): loss_ratio = -1 while loss_ratio != loss_ratio_target: rate = (rate_hi + rate_lo) / 2.0 - if rate == rate_hi or rate == rate_lo: + if rate in (rate_hi, rate_lo): break loss_rate = math.exp(lfit_func(trace, rate, mrr, spread)) loss_ratio = loss_rate / rate if loss_ratio > loss_ratio_target: - trace("halving down", rate) + trace(u"halving down", rate) rate_hi = rate elif loss_ratio < loss_ratio_target: - trace("halving up", rate) + trace(u"halving up", rate) rate_lo = rate - trace("found", rate) + trace(u"found", rate) return rate @staticmethod @@ -428,36 +435,39 @@ class PLRsearch(object): :param trace: A multiprocessing-friendly logging function (closure). :param lfit_func: Fitting function, typically lfit_spread or lfit_erf. - :param result_list: List of trial measurement results. + :param trial_result_list: List of trial measurement results. :param mrr: The mrr parameter for the fitting function. :param spread: The spread parameter for the fittinmg function. :type trace: function (str, object) -> None :type lfit_func: Function from 3 floats to float. - :type result_list: list of MLRsearch.ReceiveRateMeasurement + :type trial_result_list: list of MLRsearch.ReceiveRateMeasurement :type mrr: float :type spread: float :returns: Logarithm of result weight for given function and parameters. :rtype: float """ log_likelihood = 0.0 - trace("log_weight for mrr", mrr) - trace("spread", spread) + trace(u"log_weight for mrr", mrr) + trace(u"spread", spread) for result in trial_result_list: - trace("for tr", result.target_tr) - trace("lc", result.loss_count) - trace("d", result.duration) + trace(u"for tr", result.target_tr) + trace(u"lc", result.loss_count) + trace(u"d", result.duration) log_avg_loss_per_second = lfit_func( - trace, result.target_tr, mrr, spread) + trace, result.target_tr, mrr, spread + ) log_avg_loss_per_trial = ( - log_avg_loss_per_second + math.log(result.duration)) + log_avg_loss_per_second + math.log(result.duration) + ) # Poisson probability computation works nice for logarithms. log_trial_likelihood = ( result.loss_count * log_avg_loss_per_trial - - math.exp(log_avg_loss_per_trial)) + - math.exp(log_avg_loss_per_trial) + ) log_trial_likelihood -= math.lgamma(1 + result.loss_count) log_likelihood += log_trial_likelihood - trace("avg_loss_per_trial", math.exp(log_avg_loss_per_trial)) - trace("log_trial_likelihood", log_trial_likelihood) + trace(u"avg_loss_per_trial", math.exp(log_avg_loss_per_trial)) + trace(u"log_trial_likelihood", log_trial_likelihood) return log_likelihood def measure_and_compute( @@ -512,12 +522,11 @@ class PLRsearch(object): :rtype: _ComputeResult """ logging.debug( - "measure_and_compute started with self %(self)r, trial_duration " - "%(dur)r, transmit_rate %(tr)r, trial_result_list %(trl)r, " - "max_rate %(mr)r, focus_trackers %(track)r, max_samples %(ms)r", - {"self": self, "dur": trial_duration, "tr": transmit_rate, - "trl": trial_result_list, "mr": max_rate, "track": focus_trackers, - "ms": max_samples}) + f"measure_and_compute started with self {self!r}, trial_duration " + f"{trial_duration!r}, transmit_rate {transmit_rate!r}, " + f"trial_result_list {trial_result_list!r}, max_rate {max_rate!r}, " + f"focus_trackers {focus_trackers!r}, max_samples {max_samples!r}" + ) # Preparation phase. dimension = 2 stretch_focus_tracker, erf_focus_tracker = focus_trackers @@ -536,11 +545,10 @@ class PLRsearch(object): start computation, return the boss pipe end. :param fitting_function: lfit_erf or lfit_stretch. - :param bias_avg: Tuple of floats to start searching around. - :param bias_cov: Covariance matrix defining initial focus shape. + :param focus_tracker: Tracker initialized to speed up the numeric + computation. :type fitting_function: Function from 3 floats to float. - :type bias_avg: 2-tuple of floats - :type bias_cov: 2-tuple of 2-tuples of floats + :type focus_tracker: None or stat_trackers.VectorStatTracker :returns: Boss end of communication pipe. :rtype: multiprocessing.Connection """ @@ -579,27 +587,31 @@ class PLRsearch(object): mrr = max_rate * (1.0 / (x_mrr + 1.0) - 0.5) + 1.0 spread = math.exp((x_spread + 1.0) / 2.0 * math.log(mrr)) logweight = self.log_weight( - trace, fitting_function, trial_result_list, mrr, spread) - value = math.log(self.find_critical_rate( - trace, fitting_function, min_rate, max_rate, - self.packet_loss_ratio_target, mrr, spread)) + trace, fitting_function, trial_result_list, mrr, spread + ) + value = math.log( + self.find_critical_rate( + trace, fitting_function, min_rate, max_rate, + self.packet_loss_ratio_target, mrr, spread + ) + ) return value, logweight dilled_function = dill.dumps(value_logweight_func) boss_pipe_end, worker_pipe_end = multiprocessing.Pipe() boss_pipe_end.send( - (dimension, dilled_function, focus_tracker, max_samples)) + (dimension, dilled_function, focus_tracker, max_samples) + ) worker = multiprocessing.Process( - target=Integrator.try_estimate_nd, args=( - worker_pipe_end, 10.0, self.trace_enabled)) + target=Integrator.try_estimate_nd, + args=(worker_pipe_end, 10.0, self.trace_enabled) + ) worker.daemon = True worker.start() return boss_pipe_end - erf_pipe = start_computing( - self.lfit_erf, erf_focus_tracker) - stretch_pipe = start_computing( - self.lfit_stretch, stretch_focus_tracker) + erf_pipe = start_computing(self.lfit_erf, erf_focus_tracker) + stretch_pipe = start_computing(self.lfit_stretch, stretch_focus_tracker) # Measurement phase. measurement = self.measurer.measure(trial_duration, transmit_rate) @@ -623,38 +635,38 @@ class PLRsearch(object): """ pipe.send(None) if not pipe.poll(10.0): - raise RuntimeError( - "Worker {name} did not finish!".format(name=name)) + raise RuntimeError(f"Worker {name} did not finish!") result_or_traceback = pipe.recv() try: value_tracker, focus_tracker, debug_list, trace_list, sampls = ( - result_or_traceback) + result_or_traceback + ) except ValueError: raise RuntimeError( - "Worker {name} failed with the following traceback:\n{tr}" - .format(name=name, tr=result_or_traceback)) - logging.info("Logs from worker %(name)r:", {"name": name}) + f"Worker {name} failed with the following traceback:\n" + f"{result_or_traceback}" + ) + logging.info(f"Logs from worker {name!r}:") for message in debug_list: logging.info(message) for message in trace_list: logging.debug(message) - logging.debug("trackers: value %(val)r focus %(foc)r", { - "val": value_tracker, "foc": focus_tracker}) + logging.debug( + f"trackers: value {value_tracker!r} focus {focus_tracker!r}" + ) return _PartialResult(value_tracker, focus_tracker, sampls) - stretch_result = stop_computing("stretch", stretch_pipe) - erf_result = stop_computing("erf", erf_pipe) + stretch_result = stop_computing(u"stretch", stretch_pipe) + erf_result = stop_computing(u"erf", erf_pipe) result = PLRsearch._get_result(measurement, stretch_result, erf_result) logging.info( - "measure_and_compute finished with trial result %(res)r " - "avg %(avg)r stdev %(stdev)r stretch %(a1)r erf %(a2)r " - "new trackers %(nt)r old trackers %(ot)r stretch samples %(ss)r " - "erf samples %(es)r", - {"res": result.measurement, - "avg": result.avg, "stdev": result.stdev, - "a1": result.stretch_exp_avg, "a2": result.erf_exp_avg, - "nt": result.trackers, "ot": old_trackers, - "ss": stretch_result.samples, "es": erf_result.samples}) + f"measure_and_compute finished with trial result " + f"{result.measurement!r} avg {result.avg!r} stdev {result.stdev!r} " + f"stretch {result.stretch_exp_avg!r} erf {result.erf_exp_avg!r} " + f"new trackers {result.trackers!r} old trackers {old_trackers!r} " + f"stretch samples {stretch_result.samples!r} erf samples " + f"{erf_result.samples!r}" + ) return result @staticmethod @@ -692,7 +704,8 @@ class PLRsearch(object): # Named tuples, for multiple local variables to be passed as return value. _PartialResult = namedtuple( - "_PartialResult", "value_tracker focus_tracker samples") + u"_PartialResult", u"value_tracker focus_tracker samples" +) """Two stat trackers and sample counter. :param value_tracker: Tracker for the value (critical load) being integrated. @@ -704,8 +717,9 @@ _PartialResult = namedtuple( """ _ComputeResult = namedtuple( - "_ComputeResult", - "measurement avg stdev stretch_exp_avg erf_exp_avg trackers") + u"_ComputeResult", + u"measurement avg stdev stretch_exp_avg erf_exp_avg trackers" +) """Measurement, 4 computation result values, pair of trackers. :param measurement: The trial measurement result obtained during computation.