feat: Upgrade to opentelemetry@0.27, keeps compatibility with v0.24

Author: marcbachmann

example/index.js

@@ -1,7 +1,7 @@
-const {MeterProvider} = require('@opentelemetry/metrics')
+const {MeterProvider} = require('@opentelemetry/sdk-metrics-base')
 const {PrometheusExporter} = require('@opentelemetry/exporter-prometheus')
 
-const exporter = new PrometheusExporter({startServer: true}, () => {
+const exporter = new PrometheusExporter({port: 9464, startServer: true}, () => {
   // eslint-disable-next-line no-console
   console.log(
     `Prometheus scrape endpoint: http://localhost:%s%s`,
@@ -16,3 +16,8 @@ const meterProvider = new MeterProvider({
 })
 
 require('opentelemetry-node-metrics')(meterProvider)
+
+
+// With opentelemetry 0.27, the proecss somehow doesn't keep any open handles
+// and stops without that
+setInterval(() => {}, 1000)

example/package-lock.json

@@ -4,11 +4,10 @@
   "description": "",
   "main": "index.js",
   "dependencies": {
-    "@opentelemetry/exporter-prometheus": "^0.14.0",
-    "@opentelemetry/metrics": "^0.14.0",
+    "@opentelemetry/exporter-prometheus": "^0.27.0",
+    "@opentelemetry/sdk-metrics-base": "^0.27.0",
     "opentelemetry-node-metrics": "file:.."
   },
-  "devDependencies": {},
   "scripts": {
     "test": "echo \"Error: no test specified\" && exit 1"
   },

example/package.json

@@ -3,7 +3,20 @@ module.exports = function setupNodeMetrics (meterProvider, config) {
   config.prefix = config.prefix ? config.prefix : ''
   config.labels = config.labels ? config.labels : {}
 
-  const meter = meterProvider.getMeter('opentelemetry-node-metrics')
+  let meter = meterProvider.getMeter('opentelemetry-node-metrics')
+
+  // keep opentelemetry compatibility with v0.24.x
+  if (!meter.createObservableGauge) {
+    meter = {
+      createObservableGauge: meter.createValueObserver.bind(meter),
+      createHistogram: meter.createValueRecorder.bind(meter),
+      createCounter: meter.createCounter.bind(meter),
+      createUpDownCounter: meter.createUpDownCounter.bind(meter)
+    }
+  }
+
+  require('./metrics/version')(meter, config)
+  require('./metrics/processStartTime')(meter, config)
   require('./metrics/eventLoopLag')(meter, config)
   require('./metrics/gc')(meter, config)
   require('./metrics/heapSizeAndUsed')(meter, config)
@@ -14,6 +27,4 @@ module.exports = function setupNodeMetrics (meterProvider, config) {
   require('./metrics/processMaxFileDescriptors')(meter, config)
   require('./metrics/processOpenFileDescriptors')(meter, config)
   require('./metrics/processRequests')(meter, config)
-  require('./metrics/processStartTime')(meter, config)
-  require('./metrics/version')(meter, config)
 }

index.js

@@ -20,47 +20,44 @@ module.exports = (meter, {prefix, labels, eventLoopMonitoringPrecision}) => {
 
   histogram.enable()
 
-  const lag = meter.createValueObserver(prefix + NODEJS_EVENTLOOP_LAG, {
+  const lag = meter.createObservableGauge(prefix + NODEJS_EVENTLOOP_LAG, {
     description: 'Lag of event loop in seconds.'
   }).bind(labels)
 
-  const lagMin = meter.createValueObserver(prefix + NODEJS_EVENTLOOP_LAG_MIN, {
+  const lagMin = meter.createObservableGauge(prefix + NODEJS_EVENTLOOP_LAG_MIN, {
     description: 'The minimum recorded event loop delay.'
   }).bind(labels)
 
-  const lagMax = meter.createValueObserver(prefix + NODEJS_EVENTLOOP_LAG_MAX, {
+  const lagMax = meter.createObservableGauge(prefix + NODEJS_EVENTLOOP_LAG_MAX, {
     description: 'The maximum recorded event loop delay.'
   }).bind(labels)
 
-  const lagMean = meter.createValueObserver(prefix + NODEJS_EVENTLOOP_LAG_MEAN, {
+  const lagMean = meter.createObservableGauge(prefix + NODEJS_EVENTLOOP_LAG_MEAN, {
     description: 'The mean of the recorded event loop delays.'
   }).bind(labels)
 
-  const lagStddev = meter.createValueObserver(prefix + NODEJS_EVENTLOOP_LAG_STDDEV, {
+  const lagStddev = meter.createObservableGauge(prefix + NODEJS_EVENTLOOP_LAG_STDDEV, {
     description: 'The standard deviation of the recorded event loop delays.'
   }).bind(labels)
 
-  const lagP50 = meter.createValueObserver(prefix + NODEJS_EVENTLOOP_LAG_P50, {
+  const lagP50 = meter.createObservableGauge(prefix + NODEJS_EVENTLOOP_LAG_P50, {
     description: 'The 50th percentile of the recorded event loop delays.'
   }).bind(labels)
 
-  const lagP90 = meter.createValueObserver(prefix + NODEJS_EVENTLOOP_LAG_P90, {
+  const lagP90 = meter.createObservableGauge(prefix + NODEJS_EVENTLOOP_LAG_P90, {
     description: 'The 90th percentile of the recorded event loop delays.'
   }).bind(labels)
 
-  const lagP99 = meter.createValueObserver(prefix + NODEJS_EVENTLOOP_LAG_P99, {
+  const lagP99 = meter.createObservableGauge(prefix + NODEJS_EVENTLOOP_LAG_P99, {
     description: 'The 99th percentile of the recorded event loop delays.'
-  }).bind(labels)
+  }, async () => {
+    const startTime = process.hrtime()
+    await new Promise((resolve) => setImmediate(() => resolve()))
 
-  function reportEventloopLag (start) {
-    const delta = process.hrtime(start)
+    const delta = process.hrtime(startTime)
     const nanosec = (delta[0] * 1e9) + delta[1]
     const seconds = nanosec / 1e9
     lag.update(seconds)
-  }
-
-  meter.createBatchObserver((observerBatchResult) => {
-    setImmediate(reportEventloopLag, process.hrtime())
 
     lagMin.update(histogram.min / 1e9)
     lagMax.update(histogram.max / 1e9)
@@ -69,8 +66,9 @@ module.exports = (meter, {prefix, labels, eventLoopMonitoringPrecision}) => {
     lagP50.update(histogram.percentile(50) / 1e9)
     lagP90.update(histogram.percentile(90) / 1e9)
     lagP99.update(histogram.percentile(99) / 1e9)
-  })
+  }).bind(labels)
 
+  lag.update(0)
 }
 
 module.exports.metricNames = [

metrics/eventLoopLag.js

@@ -7,7 +7,7 @@ const DEFAULT_GC_DURATION_BUCKETS = [0.001, 0.01, 0.1, 1, 2, 5]
 module.exports = (meter, {prefix, labels, gcDurationBuckets}) => {
   const boundaries = gcDurationBuckets || DEFAULT_GC_DURATION_BUCKETS
 
-  const histogram = meter.createValueRecorder(prefix + NODEJS_GC_DURATION_SECONDS, {
+  const histogram = meter.createHistogram(prefix + NODEJS_GC_DURATION_SECONDS, {
     description: 'Garbage collection duration by kind, one of major, minor, incremental or weakcb.',
     boundaries
   })