FEATURE:: Support for metrics collection - Prometheus and Open Telemetry (#3420)

* adding support for prometheus and grafana * open telemetry * lint fixes * missing counter and telemetry standardization --------- Co-authored-by: Henry <hzj94@hotmail.com>
2026-06-28 17:01:00 +03:00 · 2024-11-08 05:30:43 +05:30
parent 8466e1a0b0
commit fe03683f0c
22 changed files with 3493 additions and 54 deletions
@@ -0,0 +1,122 @@
+import { FLOWISE_METRIC_COUNTERS, IMetricsProvider } from '../Interface.Metrics'
+import express from 'express'
+import promClient, { Counter, Histogram, Registry } from 'prom-client'
+import { getVersion } from 'flowise-components'
+
+export class Prometheus implements IMetricsProvider {
+    private app: express.Application
+    private readonly register: Registry
+    private counters: Map<string, promClient.Counter<string> | promClient.Gauge<string> | promClient.Histogram<string>>
+    private requestCounter: Counter<string>
+    private httpRequestDurationMicroseconds: Histogram<string>
+
+    constructor(app: express.Application) {
+        this.app = app
+        this.register = new promClient.Registry()
+    }
+
+    public getName(): string {
+        return 'Prometheus'
+    }
+
+    async initializeCounters(): Promise<void> {
+        const serviceName: string = process.env.METRICS_SERVICE_NAME || 'FlowiseAI'
+        this.register.setDefaultLabels({
+            app: serviceName
+        })
+
+        // look at the FLOWISE_COUNTER enum in Interface.Metrics.ts and get all values
+        // for each counter in the enum, create a new promClient.Counter and add it to the registry
+        this.counters = new Map<string, promClient.Counter<string>>()
+        const enumEntries = Object.entries(FLOWISE_METRIC_COUNTERS)
+        enumEntries.forEach(([name, value]) => {
+            // derive proper counter name from the enum value (chatflow_created = Chatflow Created)
+            const properCounterName: string = name.replace(/_/g, ' ').replace(/\b\w/g, (l) => l.toUpperCase())
+            this.counters.set(
+                value,
+                new promClient.Counter({
+                    name: value,
+                    help: `Total number of ${properCounterName}`,
+                    labelNames: ['status']
+                })
+            )
+        })
+
+        // in addition to the enum counters, add a few more custom counters
+        // version, http_request_duration_ms, http_requests_total
+        const versionGaugeCounter = new promClient.Gauge({
+            name: 'flowise_version_info',
+            help: 'Flowise version info.',
+            labelNames: ['version']
+        })
+
+        const { version } = await getVersion()
+        versionGaugeCounter.set({ version: 'v' + version }, 1)
+        this.counters.set('flowise_version', versionGaugeCounter)
+
+        this.httpRequestDurationMicroseconds = new promClient.Histogram({
+            name: 'http_request_duration_ms',
+            help: 'Duration of HTTP requests in ms',
+            labelNames: ['method', 'route', 'code'],
+            buckets: [1, 5, 15, 50, 100, 200, 300, 400, 500] // buckets for response time from 0.1ms to 500ms
+        })
+        this.counters.set('http_request_duration_ms', this.httpRequestDurationMicroseconds)
+
+        this.requestCounter = new Counter({
+            name: 'http_requests_total',
+            help: 'Total number of HTTP requests',
+            labelNames: ['method', 'path', 'status']
+        })
+        this.counters.set('http_requests_total', this.requestCounter)
+
+        this.registerMetrics()
+        await this.setupMetricsEndpoint()
+    }
+
+    async setupMetricsEndpoint() {
+        // Add Prometheus middleware to the app
+        this.app.use('/api/v1/metrics', async (req, res) => {
+            res.set('Content-Type', this.register.contentType)
+            const currentMetrics = await this.register.metrics()
+            res.send(currentMetrics).end()
+        })
+
+        // Runs before each requests
+        this.app.use((req, res, next) => {
+            res.locals.startEpoch = Date.now()
+            next()
+        })
+
+        // Runs after each requests
+        this.app.use((req, res, next) => {
+            res.on('finish', async () => {
+                if (res.locals.startEpoch) {
+                    this.requestCounter.inc()
+                    const responseTimeInMs = Date.now() - res.locals.startEpoch
+                    this.httpRequestDurationMicroseconds
+                        .labels(req.method, req.baseUrl, res.statusCode.toString())
+                        .observe(responseTimeInMs)
+                }
+            })
+            next()
+        })
+    }
+
+    public incrementCounter(counter: FLOWISE_METRIC_COUNTERS, payload: any) {
+        // increment the counter with the payload
+        if (this.counters.has(counter)) {
+            ;(this.counters.get(counter) as Counter<string>).labels(payload).inc()
+        }
+    }
+
+    private registerMetrics() {
+        if (process.env.METRICS_INCLUDE_NODE_METRICS !== 'false') {
+            // enable default metrics like CPU usage, memory usage, etc.
+            promClient.collectDefaultMetrics({ register: this.register })
+        }
+        // Add our custom metrics to the registry
+        for (const counter of this.counters.values()) {
+            this.register.registerMetric(counter)
+        }
+    }
+}