src/performance/PerformanceStatistics.ts

   1 // Partial Copyright Jerome Benoit. 2021. All Rights Reserved.
   2
   3 import { CircularArray, DEFAULT_CIRCULAR_ARRAY_SIZE } from '../utils/CircularArray';
   4 import { IncomingRequestCommand, RequestCommand } from '../types/ocpp/Requests';
   5 import { PerformanceEntry, PerformanceObserver, performance } from 'perf_hooks';
   6 import Statistics, { StatisticsData, TimeSeries } from '../types/Statistics';
   7
   8 import { ChargingStationWorkerMessageEvents } from '../types/ChargingStationWorker';
   9 import Configuration from '../utils/Configuration';
  10 import { MessageType } from '../types/ocpp/MessageType';
  11 import { URL } from 'url';
  12 import Utils from '../utils/Utils';
  13 import logger from '../utils/Logger';
  14 import { parentPort } from 'worker_threads';
  15
  16 export default class PerformanceStatistics {
  17   private static readonly instances: Map<string, PerformanceStatistics> = new Map<string, PerformanceStatistics>();
  18   private readonly objId: string;
  19   private readonly objName: string;
  20   private performanceObserver: PerformanceObserver;
  21   private readonly statistics: Statistics;
  22   private displayInterval: NodeJS.Timeout;
  23
  24   private constructor(objId: string, objName: string, uri: URL) {
  25     this.objId = objId;
  26     this.objName = objName;
  27     this.initializePerformanceObserver();
  28     this.statistics = { id: this.objId ?? 'Object id not specified', name: this.objName ?? 'Object name not specified', uri: uri.toString(), createdAt: new Date(), statisticsData: new Map<string, Partial<StatisticsData>>() };
  29   }
  30
  31   public static getInstance(objId: string, objName: string, uri: URL): PerformanceStatistics {
  32     if (!PerformanceStatistics.instances.has(objId)) {
  33       PerformanceStatistics.instances.set(objId, new PerformanceStatistics(objId, objName, uri));
  34     }
  35     return PerformanceStatistics.instances.get(objId);
  36   }
  37
  38   public static beginMeasure(id: string): string {
  39     const markId = `${id.charAt(0).toUpperCase() + id.slice(1)}~${Utils.generateUUID()}`;
  40     performance.mark(markId);
  41     return markId;
  42   }
  43
  44   public static endMeasure(name: string, markId: string): void {
  45     performance.measure(name, markId);
  46     performance.clearMarks(markId);
  47   }
  48
  49   public addRequestStatistic(command: RequestCommand | IncomingRequestCommand, messageType: MessageType): void {
  50     switch (messageType) {
  51       case MessageType.CALL_MESSAGE:
  52         if (this.statistics.statisticsData.has(command) && this.statistics.statisticsData.get(command)?.countRequest) {
  53           this.statistics.statisticsData.get(command).countRequest++;
  54         } else {
  55           this.statistics.statisticsData.set(command, Object.assign({ countRequest: 1 }, this.statistics.statisticsData.get(command)));
  56         }
  57         break;
  58       case MessageType.CALL_RESULT_MESSAGE:
  59         if (this.statistics.statisticsData.has(command) && this.statistics.statisticsData.get(command)?.countResponse) {
  60           this.statistics.statisticsData.get(command).countResponse++;
  61         } else {
  62           this.statistics.statisticsData.set(command, Object.assign({ countResponse: 1 }, this.statistics.statisticsData.get(command)));
  63         }
  64         break;
  65       case MessageType.CALL_ERROR_MESSAGE:
  66         if (this.statistics.statisticsData.has(command) && this.statistics.statisticsData.get(command)?.countError) {
  67           this.statistics.statisticsData.get(command).countError++;
  68         } else {
  69           this.statistics.statisticsData.set(command, Object.assign({ countError: 1 }, this.statistics.statisticsData.get(command)));
  70         }
  71         break;
  72       default:
  73         logger.error(`${this.logPrefix()} wrong message type ${messageType}`);
  74         break;
  75     }
  76   }
  77
  78   public start(): void {
  79     this.startLogStatisticsInterval();
  80     if (Configuration.getPerformanceStorage().enabled) {
  81       logger.info(`${this.logPrefix()} storage enabled: type ${Configuration.getPerformanceStorage().type}, uri: ${Configuration.getPerformanceStorage().uri}`);
  82     }
  83   }
  84
  85   public stop(): void {
  86     if (this.displayInterval) {
  87       clearInterval(this.displayInterval);
  88     }
  89     performance.clearMarks();
  90     this.performanceObserver?.disconnect();
  91   }
  92
  93   public restart(): void {
  94     this.stop();
  95     this.start();
  96   }
  97
  98   private initializePerformanceObserver(): void {
  99     this.performanceObserver = new PerformanceObserver((list) => {
 100       const lastPerformanceEntry = list.getEntries()[0];
 101       this.addPerformanceEntryToStatistics(lastPerformanceEntry);
 102       logger.debug(`${this.logPrefix()} '${lastPerformanceEntry.name}' performance entry: %j`, lastPerformanceEntry);
 103     });
 104     this.performanceObserver.observe({ entryTypes: ['measure'] });
 105   }
 106
 107   private logStatistics(): void {
 108     logger.info(this.logPrefix() + ' %j', this.statistics);
 109   }
 110
 111   private startLogStatisticsInterval(): void {
 112     if (Configuration.getLogStatisticsInterval() > 0) {
 113       this.displayInterval = setInterval(() => {
 114         this.logStatistics();
 115       }, Configuration.getLogStatisticsInterval() * 1000);
 116       logger.info(this.logPrefix() + ' logged every ' + Utils.formatDurationSeconds(Configuration.getLogStatisticsInterval()));
 117     } else {
 118       logger.info(this.logPrefix() + ' log interval is set to ' + Configuration.getLogStatisticsInterval().toString() + '. Not logging statistics');
 119     }
 120   }
 121
 122   private median(dataSet: number[]): number {
 123     if (Array.isArray(dataSet) && dataSet.length === 1) {
 124       return dataSet[0];
 125     }
 126     const sortedDataSet = dataSet.slice().sort((a, b) => (a - b));
 127     const middleIndex = Math.floor(sortedDataSet.length / 2);
 128     if (sortedDataSet.length % 2) {
 129       return sortedDataSet[middleIndex / 2];
 130     }
 131     return (sortedDataSet[(middleIndex - 1)] + sortedDataSet[middleIndex]) / 2;
 132   }
 133
 134   // TODO: use order statistics tree https://en.wikipedia.org/wiki/Order_statistic_tree
 135   private percentile(dataSet: number[], percentile: number): number {
 136     if (percentile < 0 && percentile > 100) {
 137       throw new RangeError('Percentile is not between 0 and 100');
 138     }
 139     if (Utils.isEmptyArray(dataSet)) {
 140       return 0;
 141     }
 142     const sortedDataSet = dataSet.slice().sort((a, b) => (a - b));
 143     if (percentile === 0) {
 144       return sortedDataSet[0];
 145     }
 146     if (percentile === 100) {
 147       return sortedDataSet[sortedDataSet.length - 1];
 148     }
 149     const percentileIndex = ((percentile / 100) * sortedDataSet.length) - 1;
 150     if (Number.isInteger(percentileIndex)) {
 151       return (sortedDataSet[percentileIndex] + sortedDataSet[percentileIndex + 1]) / 2;
 152     }
 153     return sortedDataSet[Math.round(percentileIndex)];
 154   }
 155
 156   private stdDeviation(dataSet: number[]): number {
 157     let totalDataSet = 0;
 158     for (const data of dataSet) {
 159       totalDataSet += data;
 160     }
 161     const dataSetMean = totalDataSet / dataSet.length;
 162     let totalGeometricDeviation = 0;
 163     for (const data of dataSet) {
 164       const deviation = data - dataSetMean;
 165       totalGeometricDeviation += deviation * deviation;
 166     }
 167     return Math.sqrt(totalGeometricDeviation / dataSet.length);
 168   }
 169
 170   private addPerformanceEntryToStatistics(entry: PerformanceEntry): void {
 171     let entryName = entry.name;
 172     // Rename entry name
 173     const MAP_NAME: Record<string, string> = {};
 174     if (MAP_NAME[entryName]) {
 175       entryName = MAP_NAME[entryName];
 176     }
 177     // Initialize command statistics
 178     if (!this.statistics.statisticsData.has(entryName)) {
 179       this.statistics.statisticsData.set(entryName, {});
 180     }
 181     // Update current statistics
 182     this.statistics.updatedAt = new Date();
 183     this.statistics.statisticsData.get(entryName).countTimeMeasurement = this.statistics.statisticsData.get(entryName)?.countTimeMeasurement
 184       ? this.statistics.statisticsData.get(entryName).countTimeMeasurement + 1
 185       : 1;
 186     this.statistics.statisticsData.get(entryName).currentTimeMeasurement = entry.duration;
 187     this.statistics.statisticsData.get(entryName).minTimeMeasurement = this.statistics.statisticsData.get(entryName)?.minTimeMeasurement
 188       ? (this.statistics.statisticsData.get(entryName).minTimeMeasurement > entry.duration ? entry.duration : this.statistics.statisticsData.get(entryName).minTimeMeasurement)
 189       : entry.duration;
 190     this.statistics.statisticsData.get(entryName).maxTimeMeasurement = this.statistics.statisticsData.get(entryName)?.maxTimeMeasurement
 191       ? (this.statistics.statisticsData.get(entryName).maxTimeMeasurement < entry.duration ? entry.duration : this.statistics.statisticsData.get(entryName).maxTimeMeasurement)
 192       : entry.duration;
 193     this.statistics.statisticsData.get(entryName).totalTimeMeasurement = this.statistics.statisticsData.get(entryName)?.totalTimeMeasurement
 194       ? this.statistics.statisticsData.get(entryName).totalTimeMeasurement + entry.duration
 195       : entry.duration;
 196     this.statistics.statisticsData.get(entryName).avgTimeMeasurement = this.statistics.statisticsData.get(entryName).totalTimeMeasurement / this.statistics.statisticsData.get(entryName).countTimeMeasurement;
 197     Array.isArray(this.statistics.statisticsData.get(entryName).timeMeasurementSeries)
 198       ? this.statistics.statisticsData.get(entryName).timeMeasurementSeries.push({ timestamp: entry.startTime, value: entry.duration })
 199       : this.statistics.statisticsData.get(entryName).timeMeasurementSeries = new CircularArray<TimeSeries>(DEFAULT_CIRCULAR_ARRAY_SIZE, { timestamp: entry.startTime, value: entry.duration });
 200     this.statistics.statisticsData.get(entryName).medTimeMeasurement = this.median(this.extractTimeSeriesValues(this.statistics.statisticsData.get(entryName).timeMeasurementSeries));
 201     this.statistics.statisticsData.get(entryName).ninetyFiveThPercentileTimeMeasurement = this.percentile(this.extractTimeSeriesValues(this.statistics.statisticsData.get(entryName).timeMeasurementSeries), 95);
 202     this.statistics.statisticsData.get(entryName).stdDevTimeMeasurement = this.stdDeviation(this.extractTimeSeriesValues(this.statistics.statisticsData.get(entryName).timeMeasurementSeries));
 203     if (Configuration.getPerformanceStorage().enabled) {
 204       parentPort.postMessage({ id: ChargingStationWorkerMessageEvents.PERFORMANCE_STATISTICS, data: this.statistics });
 205     }
 206   }
 207
 208   private extractTimeSeriesValues(timeSeries: CircularArray<TimeSeries>): number[] {
 209     return timeSeries.map((timeSeriesItem) => timeSeriesItem.value);
 210   }
 211
 212   private logPrefix(): string {
 213     return Utils.logPrefix(` ${this.objName} | Performance statistics`);
 214   }
 215 }