fix: telemetry (#4)

* fix: telemetry

* release: v0.2.2

* chore: comments

Author: Simone Sanfratello

package.json

@@ -1,6 +1,6 @@
 {
   "name": "e-ipfs-core-lib",
-  "version": "0.2.1",
+  "version": "0.2.2",
   "description": "E-IPFS core library",
   "license": "(Apache-2.0 AND MIT)",
   "homepage": "https://github.com/elastic-ipfs/core-lib",
@@ -14,7 +14,7 @@
     "node": "18.12"
   },
   "dependencies": {
-    "@aws-sdk/util-dynamodb": "^3.200.0",
+    "@aws-sdk/util-dynamodb": "^3.216.0",
     "bl": "^6.0.0",
     "hdr-histogram-js": "^3.0.0",
     "js-yaml": "^4.1.0",
@@ -32,7 +32,7 @@
     "dedent": "^0.7.0",
     "split2": "^4.1.0",
     "standard": "^17.0.0",
-    "tap": "^16.3.0"
+    "tap": "^16.3.2"
   },
   "type": "module",
   "exports": "./src/index.js",

src/telemetry.js

@@ -1,30 +1,36 @@
 
 import { readFileSync } from 'fs'
 import { load as ymlLoad } from 'js-yaml'
-import { build as buildHistogram } from 'hdr-histogram-js'
+import * as hdr from 'hdr-histogram-js'
 
 const PERCENTILES = [0.001, 0.01, 0.1, 1, 2.5, 10, 25, 50, 75, 90, 97.5, 99, 99.9, 99.99, 99.999]
 
 class Aggregator {
-  constructor (category, description, metric) {
+  constructor (category, description, metric, type) {
     this.tag = `${category}-${metric}`
     this.description = `${description} (${metric})`
     this.exportName = this.tag.replaceAll('-', '_')
 
-    if (category.match(/active|pending/)) {
-      this.type = 'gauge'
-    } else if (metric === 'durations') {
-      this.type = 'histogram'
+    // type is optional
+    if (!type) {
+      // set the type by the metric
+      if (metric === 'durations') {
+        this.type = 'histogram'
+      } else {
+        this.type = 'counter'
+        this.exportName += '_total'
+      }
     } else {
-      this.type = 'counter'
-      this.exportName += '_total'
+      this.type = type
     }
 
     this.sum = 0
-    this.histogram = buildHistogram({
+    hdr.initWebAssemblySync()
+    this.histogram = hdr.build({
       lowestDiscernibleValue: 1,
       highestTrackableValue: 1e9,
-      numberOfSignificantValueDigits: 5
+      numberOfSignificantValueDigits: 5,
+      useWebAssembly: true
     })
   }
 
@@ -103,8 +109,8 @@ class Telemetry {
     this.metrics.clear()
   }
 
-  createMetric (category, description, metric) {
-    const instance = new Aggregator(category, description, metric)
+  createMetric (category, description, metric, type) {
+    const instance = new Aggregator(category, description, metric, type)
 
     this.metrics.set(instance.tag, instance)
   }

test/telemetry.test.js

@@ -168,34 +168,34 @@ t.test('Telemetry', async t => {
       const telemetry = new Telemetry({ configFile, logger })
       telemetry.clear()
       telemetry.createMetric('c1', 'COUNTER', 'durations')
-      telemetry.createMetric('c2-active', 'GAUGE', 'count')
+      telemetry.createMetric('c2', 'GAUGE', 'count', 'gauge')
       telemetry.createMetric('c3', 'HISTOGRAM', 'durations')
 
       t.equal(telemetry.export(), dedent`
-      # HELP c2_active_count GAUGE (count)
-      # TYPE c2_active_count gauge
-      c2_active_count 0 now`.trim()
+      # HELP c2_count GAUGE (count)
+      # TYPE c2_count gauge
+      c2_count 0 now`.trim()
       )
     })
 
     t.test('should get the metrics result with registered metrics and values', async t => {
       const telemetry = new Telemetry({ configFile, logger })
       telemetry.clear()
       telemetry.createMetric('c1', 'COUNTER', 'count')
-      telemetry.createMetric('c2-active', 'GAUGE', 'count')
+      telemetry.createMetric('c2', 'GAUGE', 'count', 'gauge')
       telemetry.createMetric('c3', 'HISTOGRAM', 'durations')
 
       telemetry.increaseCount('c1', 1)
-      telemetry.increaseCount('c2-active', 2)
+      telemetry.increaseCount('c2', 2)
       telemetry.ensureMetric('c3', 'durations').record(3)
 
       t.equal(telemetry.export(), dedent`
       # HELP c1_count_total COUNTER (count)
       # TYPE c1_count_total counter
       c1_count_total 1 now
-      # HELP c2_active_count GAUGE (count)
-      # TYPE c2_active_count gauge
-      c2_active_count 2 now
+      # HELP c2_count GAUGE (count)
+      # TYPE c2_count gauge
+      c2_count 2 now
       # HELP c3_durations HISTOGRAM (durations)
       # TYPE c3_durations histogram
       c3_durations_count 1 now