feat: Report relay metrics

package.json

@@ -1,6 +1,6 @@
 {
  "name": "@foxssake/noray",
- "version": "1.2.0",
+ "version": "1.3.0",
  "description": "Online multiplayer orchestrator and potential game platform",
  "main": "src/noray.mjs",
  "bin": {

src/relay/udp.relay.cleanup.mjs

@@ -2,6 +2,14 @@
 import { UDPRelayHandler } from './udp.relay.handler.mjs'
 /* eslint-enable */
 import { time } from '../utils.mjs'
+import * as prometheus from 'prom-client'
+import { metricsRegistry } from '../metrics/metrics.registry.mjs'
+
+const expiredRelayCounter = new prometheus.Counter({
+ name: 'noray_relay_expired',
+ help: 'Count of expired relays',
+ registers: [metricsRegistry]
+})
 
 /**
 * Remove idle relays.
@@ -14,7 +22,8 @@ export function cleanupUdpRelayTable (relayHandler, timeout) {
  relayHandler.relayTable
  .map(relay => [relay, Math.max(relay.lastSent, relay.lastReceived)])
  .filter(([_, lastTraffic]) => lastTraffic <= timeCutoff)
- .forEach(([relay, _]) =>
+ .forEach(([relay, _]) => {
  relayHandler.freeRelay(relay)
- )
+ expiredRelayCounter.inc()
+ })
 }

src/relay/udp.relay.handler.mjs

@@ -6,9 +6,35 @@ import { UDPSocketPool } from './udp.socket.pool.mjs'
 import { time } from '../utils.mjs'
 import { EventEmitter } from 'node:events'
 import logger from '../logger.mjs'
+import * as prometheus from 'prom-client'
+import { metricsRegistry } from '../metrics/metrics.registry.mjs'
 
 const log = logger.child({ name: 'UDPRelayHandler' })
 
+const relayDurationHistogram = new prometheus.Histogram({
+ name: 'noray_relay_duration',
+ help: 'Time it takes to relay a packet',
+ registers: [metricsRegistry]
+})
+
+const relaySizeHistorgram = new prometheus.Histogram({
+ name: 'noray_relay_size',
+ help: 'Size of the packet being relayed',
+ registers: [metricsRegistry]
+})
+
+const relayDropCounter = new prometheus.Counter({
+ name: 'noray_relay_drop_count',
+ help: 'Number of relay packets dropped',
+ registers: [metricsRegistry]
+})
+
+const activeRelayGauge = new prometheus.Gauge({
+ name: 'noray_relay_count',
+ help: 'Count of currently active relays',
+ registers: [metricsRegistry]
+})
+
 /**
 * Class implementing the actual relay logic.
 *
@@ -74,6 +100,8 @@ export class UDPRelayHandler extends EventEmitter {
  this.#relayTable.push(relay)
  log.trace({ relay }, 'Relay created')
 
+ activeRelayGauge.inc()
+
  return relay
  }
 
@@ -104,6 +132,9 @@ export class UDPRelayHandler extends EventEmitter {
 
  this.#socketPool.returnPort(relay.port)
  this.#relayTable = this.#relayTable.filter((_, i) => i !== idx)
+
+ activeRelayGauge.dec()
+
  return true
  }
 
@@ -112,6 +143,8 @@ export class UDPRelayHandler extends EventEmitter {
  */
  clear () {
  this.relayTable.forEach(entry => this.freeRelay(entry))
+
+ activeRelayGauge.reset()
  }
 
  /**
@@ -124,6 +157,8 @@ export class UDPRelayHandler extends EventEmitter {
  * @fires UDPRelayHandler#drop
  */
  relay (msg, sender, target) {
+ const measure = relayDurationHistogram.startTimer()
+
  const senderRelay = this.#relayTable.find(r =>
  r.address.port === sender.port && r.address.address === sender.address
  )
@@ -132,6 +167,10 @@ export class UDPRelayHandler extends EventEmitter {
  if (!senderRelay || !targetRelay) {
  // We don't have a relay for the sender, target, or both
  this.emit('drop', senderRelay, targetRelay, sender, target, msg)
+
+ relayDropCounter.inc()
+ measure()
+
  return false
  }
 
@@ -149,6 +188,9 @@ export class UDPRelayHandler extends EventEmitter {
  senderRelay.lastReceived = time()
  targetRelay.lastSent = time()
 
+ relaySizeHistorgram.observe(msg?.byteLength ?? 0)
+ measure()
+
  return true
  }
 

src/relay/udp.remote.registrar.mjs

@@ -5,9 +5,29 @@ import dgram from 'node:dgram'
 import assert from 'node:assert'
 import logger from '../logger.mjs'
 import { requireParam } from '../assertions.mjs'
+import * as prometheus from 'prom-client'
+import { metricsRegistry } from '../metrics/metrics.registry.mjs'
 
 const log = logger.child({ name: 'UDPRemoteRegistrar' })
 
+const registerSuccessCounter = new prometheus.Counter({
+ name: 'noray_remote_registrar_success',
+ help: 'Number of successful remote address registrations',
+ registers: [metricsRegistry]
+})
+
+const registerFailCounter = new prometheus.Counter({
+ name: 'noray_remote_registrar_fail',
+ help: 'Number of failed remote address registrations',
+ registers: [metricsRegistry]
+})
+
+const registerRepatCounter = new prometheus.Counter({
+ name: 'noray_remote_registrar_repeat',
+ help: 'Number of redundant remote address registrations',
+ registers: [metricsRegistry]
+})
+
 /**
 * @summary Class for remote address registration over UDP.
 *
@@ -80,12 +100,15 @@ export class UDPRemoteRegistrar {
  if (host.rinfo) {
  // Host has already remote info registered
  this.#socket.send('OK', rinfo.port, rinfo.address)
+ registerRepatCounter.inc()
  return
  }
 
  host.rinfo = rinfo
  this.#socket.send('OK', rinfo.port, rinfo.address)
+ registerSuccessCounter.inc()
  } catch (e) {
+ registerFailCounter.inc()
  this.#socket.send(e.message ?? 'Error', rinfo.port, rinfo.address)
  }
  }