feat: allow per-component metrics to be collected (#1061)

Implements the idea from #1060 - allows us to get some insight into what's happening in a libp2p node out side of just bandwidth stats.

Configures a few default metrics if metrics are enabled - current connections, the state of the dial queue, etc.

Also makes the `Metrics` class not depend on the `ConnectionManager` class, otherwise we can't collect simple metrics from the connection manager class due to the circular dependency.

.github/workflows/main.yml

@@ -19,7 +19,7 @@ jobs:
     - run: npx aegir lint
     - run: npx aegir build
     - run: npx aegir dep-check
-    - uses: ipfs/aegir/actions/bundle-size@v32.1.0
+    - uses: ipfs/aegir/actions/bundle-size
       name: size
       with:
         github_token: ${{ secrets.GITHUB_TOKEN }}

src/connection-manager/index.js

@@ -32,6 +32,10 @@ const defaultOptions = {
   defaultPeerValue: 1
 }
 
+const METRICS_COMPONENT = 'connection-manager'
+const METRICS_PEER_CONNECTIONS = 'peer-connections'
+const METRICS_ALL_CONNECTIONS = 'all-connections'
+
 /**
  * @typedef {import('../')} Libp2p
  * @typedef {import('libp2p-interfaces/src/connection').Connection} Connection
@@ -160,6 +164,8 @@ class ConnectionManager extends EventEmitter {
 
     await Promise.all(tasks)
     this.connections.clear()
+    this._libp2p.metrics && this._libp2p.metrics.updateComponentMetric(METRICS_COMPONENT, METRICS_PEER_CONNECTIONS, 0)
+    this._libp2p.metrics && this._libp2p.metrics.updateComponentMetric(METRICS_COMPONENT, METRICS_ALL_CONNECTIONS, 0)
   }
 
   /**
@@ -211,10 +217,13 @@ class ConnectionManager extends EventEmitter {
     const storedConn = this.connections.get(peerIdStr)
 
     this.emit('peer:connect', connection)
+
     if (storedConn) {
       storedConn.push(connection)
     } else {
       this.connections.set(peerIdStr, [connection])
+      this._libp2p.metrics && this._libp2p.metrics.updateComponentMetric(METRICS_COMPONENT, METRICS_PEER_CONNECTIONS, this.connections.size)
+      this._libp2p.metrics && this._libp2p.metrics.updateComponentMetric(METRICS_COMPONENT, METRICS_ALL_CONNECTIONS, this.size)
     }
 
     this._libp2p.peerStore.keyBook.set(peerId, peerId.pubKey)
@@ -243,7 +252,12 @@ class ConnectionManager extends EventEmitter {
       this.connections.delete(peerId)
       this._peerValues.delete(connection.remotePeer.toB58String())
       this.emit('peer:disconnect', connection)
+
+      this._libp2p.metrics && this._libp2p.metrics.onPeerDisconnected(connection.remotePeer)
     }
+
+    this._libp2p.metrics && this._libp2p.metrics.updateComponentMetric(METRICS_COMPONENT, METRICS_PEER_CONNECTIONS, this.connections.size)
+    this._libp2p.metrics && this._libp2p.metrics.updateComponentMetric(METRICS_COMPONENT, METRICS_ALL_CONNECTIONS, this.size)
   }
 
   /**

src/dialer/index.js

@@ -22,6 +22,10 @@ const {
   MAX_ADDRS_TO_DIAL
 } = require('../constants')
 
+const METRICS_COMPONENT = 'dialler'
+const METRICS_PENDING_DIALS = 'pending-dials'
+const METRICS_PENDING_DIAL_TARGETS = 'pending-dials-targers'
+
 /**
  * @typedef {import('libp2p-interfaces/src/connection').Connection} Connection
  * @typedef {import('peer-id')} PeerId
@@ -44,6 +48,7 @@ const {
  * @property {number} [maxDialsPerPeer = MAX_PER_PEER_DIALS] - Number of max concurrent dials per peer.
  * @property {number} [dialTimeout = DIAL_TIMEOUT] - How long a dial attempt is allowed to take.
  * @property {Record<string, Resolver>} [resolvers = {}] - multiaddr resolvers to use when dialing
+ * @property {import('../metrics')} [metrics]
  *
  * @typedef DialTarget
  * @property {string} id
@@ -69,7 +74,8 @@ class Dialer {
     maxAddrsToDial = MAX_ADDRS_TO_DIAL,
     dialTimeout = DIAL_TIMEOUT,
     maxDialsPerPeer = MAX_PER_PEER_DIALS,
-    resolvers = {}
+    resolvers = {},
+    metrics
   }) {
     this.transportManager = transportManager
     this.peerStore = peerStore
@@ -81,6 +87,7 @@ class Dialer {
     this.tokens = [...new Array(maxParallelDials)].map((_, index) => index)
     this._pendingDials = new Map()
     this._pendingDialTargets = new Map()
+    this._metrics = metrics
 
     for (const [key, value] of Object.entries(resolvers)) {
       Multiaddr.resolvers.set(key, value)
@@ -104,6 +111,9 @@ class Dialer {
       pendingTarget.reject(new AbortError('Dialer was destroyed'))
     }
     this._pendingDialTargets.clear()
+
+    this._metrics && this._metrics.updateComponentMetric(METRICS_COMPONENT, METRICS_PENDING_DIALS, 0)
+    this._metrics && this._metrics.updateComponentMetric(METRICS_COMPONENT, METRICS_PENDING_DIAL_TARGETS, 0)
   }
 
   /**
@@ -153,6 +163,7 @@ class Dialer {
     const id = `${(parseInt(String(Math.random() * 1e9), 10)).toString() + Date.now()}`
     const cancellablePromise = new Promise((resolve, reject) => {
       this._pendingDialTargets.set(id, { resolve, reject })
+      this._metrics && this._metrics.updateComponentMetric(METRICS_COMPONENT, METRICS_PENDING_DIAL_TARGETS, this._pendingDialTargets.size)
     })
 
     try {
@@ -164,6 +175,7 @@ class Dialer {
       return dialTarget
     } finally {
       this._pendingDialTargets.delete(id)
+      this._metrics && this._metrics.updateComponentMetric(METRICS_COMPONENT, METRICS_PENDING_DIAL_TARGETS, this._pendingDialTargets.size)
     }
   }
 
@@ -252,9 +264,13 @@ class Dialer {
       destroy: () => {
         timeoutController.clear()
         this._pendingDials.delete(dialTarget.id)
+        this._metrics && this._metrics.updateComponentMetric(METRICS_COMPONENT, METRICS_PENDING_DIALS, this._pendingDials.size)
       }
     }
     this._pendingDials.set(dialTarget.id, pendingDial)
+
+    this._metrics && this._metrics.updateComponentMetric(METRICS_COMPONENT, METRICS_PENDING_DIALS, this._pendingDials.size)
+
     return pendingDial
   }
 

src/index.js

@@ -197,10 +197,11 @@ class Libp2p extends EventEmitter {
 
     // Create Metrics
     if (this._options.metrics.enabled) {
-      this.metrics = new Metrics({
-        ...this._options.metrics,
-        connectionManager: this.connectionManager
+      const metrics = new Metrics({
+        ...this._options.metrics
       })
+
+      this.metrics = metrics
     }
 
     // Create keychain
@@ -262,6 +263,7 @@ class Libp2p extends EventEmitter {
     this.dialer = new Dialer({
       transportManager: this.transportManager,
       peerStore: this.peerStore,
+      metrics: this.metrics,
       ...this._options.dialer
     })
 

src/metrics/index.js

@@ -24,9 +24,6 @@ const directionToEvent = {
  */
 
 /**
- * @typedef MetricsProperties
- * @property {import('../connection-manager')} connectionManager
- *
  * @typedef MetricsOptions
  * @property {number} [computeThrottleMaxQueueSize = defaultOptions.computeThrottleMaxQueueSize]
  * @property {number} [computeThrottleTimeout = defaultOptions.computeThrottleTimeout]
@@ -37,7 +34,7 @@ const directionToEvent = {
 class Metrics {
   /**
    * @class
-   * @param {MetricsProperties & MetricsOptions} options
+   * @param {MetricsOptions} options
    */
   constructor (options) {
     this._options = mergeOptions(defaultOptions, options)
@@ -47,10 +44,7 @@ class Metrics {
     this._oldPeers = oldPeerLRU(this._options.maxOldPeersRetention)
     this._running = false
     this._onMessage = this._onMessage.bind(this)
-    this._connectionManager = options.connectionManager
-    this._connectionManager.on('peer:disconnect', (connection) => {
-      this.onPeerDisconnected(connection.remotePeer)
-    })
+    this._componentMetrics = new Map()
   }
 
   /**
@@ -94,6 +88,22 @@ class Metrics {
     return Array.from(this._peerStats.keys())
   }
 
+  /**
+   * @returns {Map}
+   */
+  getComponentMetrics () {
+    return this._componentMetrics
+  }
+
+  updateComponentMetric (component, metric, value) {
+    if (!this._componentMetrics.has(component)) {
+      this._componentMetrics.set(component, new Map())
+    }
+
+    const map = this._componentMetrics.get(component)
+    map.set(metric, value)
+  }
+
   /**
    * Returns the `Stats` object for the given `PeerId` whether it
    * is a live peer, or in the disconnected peer LRU cache.

test/metrics/index.spec.js

@@ -3,9 +3,6 @@
 
 const { expect } = require('aegir/utils/chai')
 const sinon = require('sinon')
-
-const { EventEmitter } = require('events')
-
 const { randomBytes } = require('libp2p-crypto')
 const duplexPair = require('it-pair/duplex')
 const pipe = require('it-pipe')
@@ -34,8 +31,7 @@ describe('Metrics', () => {
     const [local, remote] = duplexPair()
     const metrics = new Metrics({
       computeThrottleMaxQueueSize: 1, // compute after every message
-      movingAverageIntervals: [10, 100, 1000],
-      connectionManager: new EventEmitter()
+      movingAverageIntervals: [10, 100, 1000]
     })
 
     metrics.trackStream({
@@ -70,8 +66,7 @@ describe('Metrics', () => {
     const [local, remote] = duplexPair()
     const metrics = new Metrics({
       computeThrottleMaxQueueSize: 1, // compute after every message
-      movingAverageIntervals: [10, 100, 1000],
-      connectionManager: new EventEmitter()
+      movingAverageIntervals: [10, 100, 1000]
     })
 
     metrics.trackStream({
@@ -119,8 +114,7 @@ describe('Metrics', () => {
     const [local2, remote2] = duplexPair()
     const metrics = new Metrics({
       computeThrottleMaxQueueSize: 1, // compute after every message
-      movingAverageIntervals: [10, 100, 1000],
-      connectionManager: new EventEmitter()
+      movingAverageIntervals: [10, 100, 1000]
     })
     const protocol = '/echo/1.0.0'
     metrics.start()
@@ -175,8 +169,7 @@ describe('Metrics', () => {
     const [local, remote] = duplexPair()
     const metrics = new Metrics({
       computeThrottleMaxQueueSize: 1, // compute after every message
-      movingAverageIntervals: [10, 100, 1000],
-      connectionManager: new EventEmitter()
+      movingAverageIntervals: [10, 100, 1000]
     })
     metrics.start()
 
@@ -231,8 +224,7 @@ describe('Metrics', () => {
     }))
 
     const metrics = new Metrics({
-      maxOldPeersRetention: 5, // Only keep track of 5
-      connectionManager: new EventEmitter()
+      maxOldPeersRetention: 5 // Only keep track of 5
     })
 
     // Clone so trackedPeers isn't modified
@@ -262,4 +254,22 @@ describe('Metrics', () => {
       expect(spy).to.have.property('callCount', 1)
     }
   })
+
+  it('should allow components to track metrics', () => {
+    const metrics = new Metrics({
+      maxOldPeersRetention: 5 // Only keep track of 5
+    })
+
+    expect(metrics.getComponentMetrics()).to.be.empty()
+
+    const component = 'my-component'
+    const metric = 'some-metric'
+    const value = 1
+
+    metrics.updateComponentMetric(component, metric, value)
+
+    expect(metrics.getComponentMetrics()).to.have.lengthOf(1)
+    expect(metrics.getComponentMetrics().get(component)).to.have.lengthOf(1)
+    expect(metrics.getComponentMetrics().get(component).get(metric)).to.equal(value)
+  })
 })