Merge pull request #6927 from overleaf/jpa-split-clsi-metrics

[misc] split clsi metrics into multiple categories

GitOrigin-RevId: 964ab57b344b92383a2937beff50139bae273a0e

libraries/metrics/index.js

@@ -131,18 +131,31 @@ function timing(key, timeSpan, sampleRate = 1, opts = {}) {
   }
 }
 
+function histogram(key, value, buckets, opts = {}) {
+  key = buildPromKey('histogram_' + key)
+  promWrapper.metric('histogram', key, buckets).observe(opts, value)
+  if (process.env.DEBUG_METRICS) {
+    console.log('doing histogram', key, buckets, opts)
+  }
+}
+
 class Timer {
-  constructor(key, sampleRate = 1, opts = {}) {
+  constructor(key, sampleRate = 1, opts = {}, buckets) {
     this.start = new Date()
     key = buildPromKey(key)
     this.key = key
     this.sampleRate = sampleRate
     this.opts = opts
+    this.buckets = buckets
   }
 
   done() {
     const timeSpan = new Date() - this.start
-    timing(this.key, timeSpan, this.sampleRate, this.opts)
+    if (this.buckets) {
+      histogram(this.key, timeSpan, this.buckets, this.opts)
+    } else {
+      timing(this.key, timeSpan, this.sampleRate, this.opts)
+    }
     return timeSpan
   }
 }
@@ -181,6 +194,7 @@ module.exports.inc = inc
 module.exports.count = count
 module.exports.summary = summary
 module.exports.timing = timing
+module.exports.histogram = histogram
 module.exports.Timer = Timer
 module.exports.gauge = gauge
 module.exports.globalGauge = globalGauge

libraries/metrics/prom_wrapper.js

@@ -29,6 +29,8 @@ const optsKey = function (opts) {
 }
 
 const extendOpts = function (opts, labelNames) {
+  // Make a clone in order to be able to re-use opts for other kinds of metrics.
+  opts = Object.assign({}, opts)
   for (const label of Array.from(labelNames)) {
     if (!opts[label]) {
       opts[label] = ''
@@ -49,15 +51,15 @@ const PromWrapper = {
   ttlInMinutes: 0,
   registry,
 
-  metric(type, name) {
-    return metrics.get(name) || new MetricWrapper(type, name)
+  metric(type, name, buckets) {
+    return metrics.get(name) || new MetricWrapper(type, name, buckets)
   },
 
   collectDefaultMetrics: prom.collectDefaultMetrics,
 }
 
 class MetricWrapper {
-  constructor(type, name) {
+  constructor(type, name, buckets) {
     metrics.set(name, this)
     this.name = name
     this.instances = new Map()
@@ -70,6 +72,19 @@ class MetricWrapper {
             help: name,
             labelNames: ['status', 'method', 'path'],
           })
+        case 'histogram':
+          return new prom.Histogram({
+            name,
+            help: name,
+            labelNames: [
+              'path',
+              'status_code',
+              'method',
+              'collection',
+              'query',
+            ],
+            buckets,
+          })
         case 'summary':
           return new prom.Summary({
             name,

libraries/metrics/test/acceptance/metrics_tests.js

@@ -1,3 +1,4 @@
+const { promisify } = require('util')
 const os = require('os')
 const http = require('http')
 const { expect } = require('chai')
@@ -5,6 +6,7 @@ const Metrics = require('../..')
 
 const HOSTNAME = os.hostname()
 const APP_NAME = 'test-app'
+const sleep = promisify(setTimeout)
 
 describe('Metrics module', function () {
   before(function () {
@@ -67,6 +69,60 @@ describe('Metrics module', function () {
     })
   })
 
+  describe('histogram()', function () {
+    it('collects in buckets', async function () {
+      const buckets = [10, 100, 1000]
+      Metrics.histogram('distance', 10, buckets)
+      Metrics.histogram('distance', 20, buckets)
+      Metrics.histogram('distance', 100, buckets)
+      Metrics.histogram('distance', 200, buckets)
+      Metrics.histogram('distance', 1000, buckets)
+      Metrics.histogram('distance', 2000, buckets)
+      const sum = await getSummarySum('histogram_distance')
+      expect(sum).to.equal(3330)
+      await checkHistogramValues('histogram_distance', {
+        10: 1,
+        100: 3,
+        1000: 5,
+        '+Inf': 6,
+      })
+    })
+  })
+
+  describe('Timer', function () {
+    beforeEach('collect timings', async function () {
+      const buckets = [10, 100, 1000]
+      for (const duration of [1, 1, 1, 15, 15, 15, 105, 105, 105]) {
+        const withBuckets = new Metrics.Timer('height', 1, {}, buckets)
+        const withOutBuckets = new Metrics.Timer('depth', 1, {})
+        await sleep(duration)
+        withBuckets.done()
+        withOutBuckets.done()
+      }
+    })
+
+    it('with buckets', async function () {
+      await checkHistogramValues('histogram_height', {
+        10: 3,
+        100: 6,
+        1000: 9,
+        '+Inf': 9,
+      })
+    })
+
+    it('without buckets', async function () {
+      await checkSummaryValues('timer_depth', {
+        0.01: 1,
+        0.05: 1,
+        0.5: 15,
+        0.9: 105,
+        0.95: 105,
+        0.99: 105,
+        0.999: 105,
+      })
+    })
+  })
+
   describe('gauge()', function () {
     it('records values', async function () {
       Metrics.gauge('water_level', 1.5)
@@ -225,6 +281,38 @@ async function getSummarySum(key) {
   return null
 }
 
+async function checkHistogramValues(key, values) {
+  const metric = getMetric(key)
+  const item = await metric.get()
+  const found = {}
+  for (const value of item.values) {
+    const bucket = value.labels.le
+    if (!bucket) continue
+    found[bucket] = value.value
+  }
+  expect(found).to.deep.equal(values)
+  return null
+}
+
+async function checkSummaryValues(key, values) {
+  const metric = getMetric(key)
+  const item = await metric.get()
+  const found = {}
+  for (const value of item.values) {
+    const quantile = value.labels.quantile
+    if (!quantile) continue
+    found[quantile] = value.value
+  }
+  for (const quantile of Object.keys(values)) {
+    expect(found[quantile]).to.be.within(
+      values[quantile] - 5,
+      values[quantile] + 5,
+      `quantile: ${quantile}`
+    )
+  }
+  return null
+}
+
 async function getMetricValue(key) {
   const metrics = await Metrics.register.getMetricsAsJSON()
   const metric = metrics.find(m => m.name === key)