server/lib/opentelemetry/metrics.ts

   1 import { Application, Request, Response } from 'express'
   2 import { Meter, metrics } from '@opentelemetry/api'
   3 import { PrometheusExporter } from '@opentelemetry/exporter-prometheus'
   4 import { MeterProvider } from '@opentelemetry/sdk-metrics'
   5 import { logger } from '@server/helpers/logger'
   6 import { CONFIG } from '@server/initializers/config'
   7 import { MVideoImmutable } from '@server/types/models'
   8 import { PlaybackMetricCreate } from '@shared/models'
   9 import {
  10   BittorrentTrackerObserversBuilder,
  11   JobQueueObserversBuilder,
  12   LivesObserversBuilder,
  13   NodeJSObserversBuilder,
  14   PlaybackMetrics,
  15   StatsObserversBuilder,
  16   ViewersObserversBuilder
  17 } from './metric-helpers'
  18
  19 class OpenTelemetryMetrics {
  20
  21   private static instance: OpenTelemetryMetrics
  22
  23   private meter: Meter
  24
  25   private onRequestDuration: (req: Request, res: Response) => void
  26
  27   private playbackMetrics: PlaybackMetrics
  28
  29   private constructor () {}
  30
  31   init (app: Application) {
  32     if (CONFIG.OPEN_TELEMETRY.METRICS.ENABLED !== true) return
  33
  34     app.use((req, res, next) => {
  35       res.once('finish', () => {
  36         if (!this.onRequestDuration) return
  37
  38         this.onRequestDuration(req as Request, res as Response)
  39       })
  40
  41       next()
  42     })
  43   }
  44
  45   registerMetrics (options: { trackerServer: any }) {
  46     if (CONFIG.OPEN_TELEMETRY.METRICS.ENABLED !== true) return
  47
  48     logger.info('Registering Open Telemetry metrics')
  49
  50     const provider = new MeterProvider({
  51       views: [
  52         ...NodeJSObserversBuilder.getViews()
  53       ]
  54     })
  55
  56     provider.addMetricReader(new PrometheusExporter({
  57       host: CONFIG.OPEN_TELEMETRY.METRICS.PROMETHEUS_EXPORTER.HOSTNAME,
  58       port: CONFIG.OPEN_TELEMETRY.METRICS.PROMETHEUS_EXPORTER.PORT
  59     }))
  60
  61     metrics.setGlobalMeterProvider(provider)
  62
  63     this.meter = metrics.getMeter('default')
  64
  65     if (CONFIG.OPEN_TELEMETRY.METRICS.HTTP_REQUEST_DURATION.ENABLED === true) {
  66       this.buildRequestObserver()
  67     }
  68
  69     this.playbackMetrics = new PlaybackMetrics(this.meter)
  70     this.playbackMetrics.buildCounters()
  71
  72     const nodeJSObserversBuilder = new NodeJSObserversBuilder(this.meter)
  73     nodeJSObserversBuilder.buildObservers()
  74
  75     const jobQueueObserversBuilder = new JobQueueObserversBuilder(this.meter)
  76     jobQueueObserversBuilder.buildObservers()
  77
  78     const statsObserversBuilder = new StatsObserversBuilder(this.meter)
  79     statsObserversBuilder.buildObservers()
  80
  81     const livesObserversBuilder = new LivesObserversBuilder(this.meter)
  82     livesObserversBuilder.buildObservers()
  83
  84     const viewersObserversBuilder = new ViewersObserversBuilder(this.meter)
  85     viewersObserversBuilder.buildObservers()
  86
  87     const bittorrentTrackerObserversBuilder = new BittorrentTrackerObserversBuilder(this.meter, options.trackerServer)
  88     bittorrentTrackerObserversBuilder.buildObservers()
  89   }
  90
  91   observePlaybackMetric (video: MVideoImmutable, metrics: PlaybackMetricCreate) {
  92     this.playbackMetrics.observe(video, metrics)
  93   }
  94
  95   private buildRequestObserver () {
  96     const requestDuration = this.meter.createHistogram('http_request_duration_ms', {
  97       unit: 'milliseconds',
  98       description: 'Duration of HTTP requests in ms'
  99     })
 100
 101     this.onRequestDuration = (req: Request, res: Response) => {
 102       const duration = Date.now() - res.locals.requestStart
 103
 104       requestDuration.record(duration, {
 105         path: this.buildRequestPath(req.originalUrl),
 106         method: req.method,
 107         statusCode: res.statusCode + ''
 108       })
 109     }
 110   }
 111
 112   private buildRequestPath (path: string) {
 113     return path.split('?')[0]
 114   }
 115
 116   static get Instance () {
 117     return this.instance || (this.instance = new this())
 118   }
 119 }
 120
 121 export {
 122   OpenTelemetryMetrics
 123 }