From 236aa41d158d70279ecb45aa2ff338e292700218 Mon Sep 17 00:00:00 2001
From: David Luna <luna.bistuer@gmail.com>
Date: Fri, 20 Jun 2025 14:07:32 +0200
Subject: [PATCH 01/19] feat: add span metrics processor

---
 packages/opentelemetry-node/lib/processors.js | 131 ++++++++++++++++++
 packages/opentelemetry-node/lib/sdk.js        |   4 +-
 2 files changed, 133 insertions(+), 2 deletions(-)
 create mode 100644 packages/opentelemetry-node/lib/processors.js

diff --git a/packages/opentelemetry-node/lib/processors.js b/packages/opentelemetry-node/lib/processors.js
new file mode 100644
index 00000000..b26043a6
--- /dev/null
+++ b/packages/opentelemetry-node/lib/processors.js
@@ -0,0 +1,131 @@
+/*
+ * Copyright Elasticsearch B.V. and contributors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+// This replicates the SDKs logic of getting processors from env
+// and also adds a new one to collect span metrics like:
+// - metric.otel.sdk.span.live.count
+// - metric.otel.sdk.span.ended.count
+
+const {getStringListFromEnv, getStringFromEnv} = require('@opentelemetry/core');
+const {BatchSpanProcessor, SimpleSpanProcessor, ConsoleSpanExporter} = require('@opentelemetry/sdk-trace-base');
+const {log} = require('./logging');
+
+/**
+ * @typedef {import('@opentelemetry/sdk-trace-base').SpanProcessor} SpanProcessor
+ */
+/**
+ * @typedef {import('@opentelemetry/sdk-trace-base').SpanExporter} SpanExporter
+ */
+
+const otlpPkgPreffix = '@opentelemetry/exporter-trace-otlp-';
+const otlpProtocol = getStringFromEnv('OTEL_EXPORTER_OTLP_TRACES_PROTOCOL') ??
+    getStringFromEnv('OTEL_EXPORTER_OTLP_PROTOCOL') ??
+    'http/protobuf';
+
+
+/** @type {SpanProcessor} */
+const spanMetricsPrcessor = {
+  forceFlush: function () {
+    return Promise.resolve();
+  },
+  onStart: function (span, parentContext) {
+    // TODO:
+    console.log('processor onStart');
+  },
+  onEnd: function (span) {
+    // TODO: update metrics
+    console.log('processor onEnd');
+  },
+  shutdown: function () {
+    // TODO: shutdown meter?
+    return Promise.resolve();
+  }
+};
+
+/**
+ * @returns {SpanExporter}
+ */
+function getOtlpExporter() {
+  let exporterPkgName = `${otlpPkgPreffix}`;
+  switch(otlpProtocol) {
+    case 'grpc':
+      exporterPkgName += 'grpc';
+      break;
+    case 'http/json':
+      exporterPkgName += 'http';
+      break;
+    case 'http/protobuf':
+      exporterPkgName += 'proto';
+      break;
+    default:
+      log.warn(`Unsupported OTLP traces protocol: ${otlpProtocol}. Using http/protobuf.`);
+      exporterPkgName += 'proto';
+  }
+  const {OTLPTraceExporter} = require(exporterPkgName);
+  return new OTLPTraceExporter();
+}
+
+/**
+ * @param {SpanProcessor[]} [processors]
+ */
+function getSpanProcessors(processors) {
+  const metricsExporters = getStringListFromEnv('OTEL_METRICS_EXPORTER') || [];
+  const metricsEnabled = metricsExporters.every((e) => e !== 'none');
+
+  console.log('getSpanProcessors', metricsEnabled, Array.isArray(processors))
+
+  if (Array.isArray(processors)) {
+    if (metricsEnabled) {
+      processors.push(spanMetricsPrcessor);
+    }
+    return processors;
+  }
+
+  // Get from env
+  const exporters = getStringListFromEnv('OTEL_TRACES_EXPORTER') ?? [];
+  const result = metricsEnabled ? [spanMetricsPrcessor] : [];
+
+  if (exporters.some(exp => exp === 'none')) {
+    log.warn('OTEL_TRACES_EXPORTER contains "none". No trace information or Spans will be exported.');
+    return [];
+  }
+
+  if (exporters.length === 0) {
+    log.debug('OTEL_TRACES_EXPORTER is empty. Using the default "otlp" exporter.')
+    exporters.push('otlp');
+  }
+
+  for (const name of exporters) {
+    switch(name) {
+      case 'otlp':
+        result.push(new BatchSpanProcessor(getOtlpExporter()));
+        break;
+      case 'console':
+        result.push(new SimpleSpanProcessor(new ConsoleSpanExporter()));
+        break;
+      case 'zipkin':
+        const {ZipkinExporter} = require('@opentelemetry/exporter-zipkin');
+        result.push(new BatchSpanProcessor(new ZipkinExporter()));
+        break;
+      case 'jaeger':
+        // TODO: this shold be installed and there is a possible issue with bundlers. refs:
+        // - is a dev-dependency? https://github.com/open-telemetry/opentelemetry-js/blob/ec17ce48d0e5a99a122da5add612a20e2dd84ed5/experimental/packages/opentelemetry-sdk-node/package.json#L76
+        // - surreunded with try catch in https://github.com/open-telemetry/opentelemetry-js/blob/ec17ce48d0e5a99a122da5add612a20e2dd84ed5/experimental/packages/opentelemetry-sdk-node/src/utils.ts#L120
+        // const {JaegerExporter} = require('@opentelemetry/exporter-jaeger');
+        // result.push(new BatchSpanProcessor(new JaegerExporter()));
+        log.warn(`OTEL_TRACES_EXPORTER value "${name}" not available yet.`);
+        break;
+      default:
+        log.warn(`Unrecognized OTEL_TRACES_EXPORTER value: ${name}.`);
+    }
+  }
+
+  console.log('getSpanProcessors.length', result)
+  return result;
+}
+
+module.exports = {
+  getSpanProcessors,
+};
diff --git a/packages/opentelemetry-node/lib/sdk.js b/packages/opentelemetry-node/lib/sdk.js
index 76d06c36..a59b4315 100644
--- a/packages/opentelemetry-node/lib/sdk.js
+++ b/packages/opentelemetry-node/lib/sdk.js
@@ -33,6 +33,7 @@ const luggite = require('./luggite');
 const {resolveDetectors} = require('./detectors');
 const {setupEnvironment, restoreEnvironment} = require('./environment');
 const {getInstrumentations} = require('./instrumentations');
+const {getSpanProcessors} = require('./processors');
 const DISTRO_VERSION = require('../package.json').version;
 
 /**
@@ -123,8 +124,7 @@ function startNodeSDK(cfg = {}) {
     const defaultConfig = {
         resourceDetectors: resolveDetectors(cfg.resourceDetectors),
         instrumentations: cfg.instrumentations || getInstrumentations(),
-        // Avoid setting `spanProcessor` or `traceExporter` to have NodeSDK
-        // use its `TracerProviderWithEnvExporters` for tracing setup.
+        spanProcessors: getSpanProcessors(cfg.spanProcessors),
     };
 
     const exporterPkgNameFromEnvVar = {

From 8417ad55ca6cfb7feed678eb2510630d67cd688c Mon Sep 17 00:00:00 2001
From: David Luna <luna.bistuer@gmail.com>
Date: Fri, 20 Jun 2025 15:56:49 +0200
Subject: [PATCH 02/19] chore(otel-node): fix lint issues

---
 packages/opentelemetry-node/lib/processors.js | 188 ++++++++++--------
 1 file changed, 105 insertions(+), 83 deletions(-)

diff --git a/packages/opentelemetry-node/lib/processors.js b/packages/opentelemetry-node/lib/processors.js
index b26043a6..f2281c70 100644
--- a/packages/opentelemetry-node/lib/processors.js
+++ b/packages/opentelemetry-node/lib/processors.js
@@ -9,7 +9,11 @@
 // - metric.otel.sdk.span.ended.count
 
 const {getStringListFromEnv, getStringFromEnv} = require('@opentelemetry/core');
-const {BatchSpanProcessor, SimpleSpanProcessor, ConsoleSpanExporter} = require('@opentelemetry/sdk-trace-base');
+const {
+    BatchSpanProcessor,
+    SimpleSpanProcessor,
+    ConsoleSpanExporter,
+} = require('@opentelemetry/sdk-trace-base');
 const {log} = require('./logging');
 
 /**
@@ -20,112 +24,130 @@ const {log} = require('./logging');
  */
 
 const otlpPkgPreffix = '@opentelemetry/exporter-trace-otlp-';
-const otlpProtocol = getStringFromEnv('OTEL_EXPORTER_OTLP_TRACES_PROTOCOL') ??
+const otlpProtocol =
+    getStringFromEnv('OTEL_EXPORTER_OTLP_TRACES_PROTOCOL') ??
     getStringFromEnv('OTEL_EXPORTER_OTLP_PROTOCOL') ??
     'http/protobuf';
 
-
 /** @type {SpanProcessor} */
 const spanMetricsPrcessor = {
-  forceFlush: function () {
-    return Promise.resolve();
-  },
-  onStart: function (span, parentContext) {
-    // TODO:
-    console.log('processor onStart');
-  },
-  onEnd: function (span) {
-    // TODO: update metrics
-    console.log('processor onEnd');
-  },
-  shutdown: function () {
-    // TODO: shutdown meter?
-    return Promise.resolve();
-  }
+    forceFlush: function () {
+        return Promise.resolve();
+    },
+    onStart: function (span, parentContext) {
+        // TODO:
+        // console.log('processor onStart');
+    },
+    onEnd: function (span) {
+        // TODO: update metrics
+        // console.log('processor onEnd');
+    },
+    shutdown: function () {
+        // TODO: shutdown meter?
+        return Promise.resolve();
+    },
 };
 
 /**
+ * @param {'otlp' | 'zipkin' | 'jaeger' | 'console'} type
  * @returns {SpanExporter}
  */
-function getOtlpExporter() {
-  let exporterPkgName = `${otlpPkgPreffix}`;
-  switch(otlpProtocol) {
-    case 'grpc':
-      exporterPkgName += 'grpc';
-      break;
-    case 'http/json':
-      exporterPkgName += 'http';
-      break;
-    case 'http/protobuf':
-      exporterPkgName += 'proto';
-      break;
-    default:
-      log.warn(`Unsupported OTLP traces protocol: ${otlpProtocol}. Using http/protobuf.`);
-      exporterPkgName += 'proto';
-  }
-  const {OTLPTraceExporter} = require(exporterPkgName);
-  return new OTLPTraceExporter();
+function getSpanExporter(type) {
+    if (type === 'zipkin') {
+        const {ZipkinExporter} = require('@opentelemetry/exporter-zipkin');
+        return new ZipkinExporter();
+    } else if (type === 'jaeger') {
+        // TODO: this shold be installed and there is a possible issue with bundlers. refs:
+        // - is a dev-dependency? https://github.com/open-telemetry/opentelemetry-js/blob/ec17ce48d0e5a99a122da5add612a20e2dd84ed5/experimental/packages/opentelemetry-sdk-node/package.json#L76
+        // - surreunded with try catch in https://github.com/open-telemetry/opentelemetry-js/blob/ec17ce48d0e5a99a122da5add612a20e2dd84ed5/experimental/packages/opentelemetry-sdk-node/src/utils.ts#L120
+        // const {JaegerExporter} = require('@opentelemetry/exporter-jaeger');
+        // result.push(new BatchSpanProcessor(new JaegerExporter()));
+    } else if (type === 'console') {
+        return new ConsoleSpanExporter();
+    }
+
+    let exporterPkgName = `${otlpPkgPreffix}`;
+    switch (otlpProtocol) {
+        case 'grpc':
+            exporterPkgName += 'grpc';
+            break;
+        case 'http/json':
+            exporterPkgName += 'http';
+            break;
+        case 'http/protobuf':
+            exporterPkgName += 'proto';
+            break;
+        default:
+            log.warn(
+                `Unsupported OTLP traces protocol: ${otlpProtocol}. Using http/protobuf.`
+            );
+            exporterPkgName += 'proto';
+    }
+    const {OTLPTraceExporter} = require(exporterPkgName);
+    return new OTLPTraceExporter();
 }
 
 /**
  * @param {SpanProcessor[]} [processors]
  */
 function getSpanProcessors(processors) {
-  const metricsExporters = getStringListFromEnv('OTEL_METRICS_EXPORTER') || [];
-  const metricsEnabled = metricsExporters.every((e) => e !== 'none');
-
-  console.log('getSpanProcessors', metricsEnabled, Array.isArray(processors))
-
-  if (Array.isArray(processors)) {
-    if (metricsEnabled) {
-      processors.push(spanMetricsPrcessor);
+    const metricsExporters =
+        getStringListFromEnv('OTEL_METRICS_EXPORTER') || [];
+    const metricsEnabled = metricsExporters.every((e) => e !== 'none');
+
+    if (Array.isArray(processors)) {
+        if (metricsEnabled) {
+            processors.push(spanMetricsPrcessor);
+        }
+        return processors;
     }
-    return processors;
-  }
 
-  // Get from env
-  const exporters = getStringListFromEnv('OTEL_TRACES_EXPORTER') ?? [];
-  const result = metricsEnabled ? [spanMetricsPrcessor] : [];
+    // Get from env
+    const exporters = getStringListFromEnv('OTEL_TRACES_EXPORTER') ?? [];
+    const result = metricsEnabled ? [spanMetricsPrcessor] : [];
 
-  if (exporters.some(exp => exp === 'none')) {
-    log.warn('OTEL_TRACES_EXPORTER contains "none". No trace information or Spans will be exported.');
-    return [];
-  }
+    if (exporters.some((exp) => exp === 'none')) {
+        log.warn(
+            'OTEL_TRACES_EXPORTER contains "none". No trace information or Spans will be exported.'
+        );
+        return [];
+    }
 
-  if (exporters.length === 0) {
-    log.debug('OTEL_TRACES_EXPORTER is empty. Using the default "otlp" exporter.')
-    exporters.push('otlp');
-  }
+    if (exporters.length === 0) {
+        log.debug(
+            'OTEL_TRACES_EXPORTER is empty. Using the default "otlp" exporter.'
+        );
+        exporters.push('otlp');
+    }
 
-  for (const name of exporters) {
-    switch(name) {
-      case 'otlp':
-        result.push(new BatchSpanProcessor(getOtlpExporter()));
-        break;
-      case 'console':
-        result.push(new SimpleSpanProcessor(new ConsoleSpanExporter()));
-        break;
-      case 'zipkin':
-        const {ZipkinExporter} = require('@opentelemetry/exporter-zipkin');
-        result.push(new BatchSpanProcessor(new ZipkinExporter()));
-        break;
-      case 'jaeger':
-        // TODO: this shold be installed and there is a possible issue with bundlers. refs:
-        // - is a dev-dependency? https://github.com/open-telemetry/opentelemetry-js/blob/ec17ce48d0e5a99a122da5add612a20e2dd84ed5/experimental/packages/opentelemetry-sdk-node/package.json#L76
-        // - surreunded with try catch in https://github.com/open-telemetry/opentelemetry-js/blob/ec17ce48d0e5a99a122da5add612a20e2dd84ed5/experimental/packages/opentelemetry-sdk-node/src/utils.ts#L120
-        // const {JaegerExporter} = require('@opentelemetry/exporter-jaeger');
-        // result.push(new BatchSpanProcessor(new JaegerExporter()));
-        log.warn(`OTEL_TRACES_EXPORTER value "${name}" not available yet.`);
-        break;
-      default:
-        log.warn(`Unrecognized OTEL_TRACES_EXPORTER value: ${name}.`);
+    for (const name of exporters) {
+        switch (name) {
+            case 'otlp':
+                result.push(new BatchSpanProcessor(getSpanExporter('otlp')));
+                break;
+            case 'console':
+                result.push(
+                    new SimpleSpanProcessor(getSpanExporter('console'))
+                );
+                break;
+            case 'zipkin':
+                result.push(new BatchSpanProcessor(getSpanExporter('zipkin')));
+                break;
+            case 'jaeger':
+                // TODO: check comment in `getSpanExporter` function
+                // result.push(new BatchSpanProcessor(getSpanExporter('zipkin')));
+                log.warn(
+                    `OTEL_TRACES_EXPORTER value "${name}" not available yet.`
+                );
+                break;
+            default:
+                log.warn(`Unrecognized OTEL_TRACES_EXPORTER value: ${name}.`);
+        }
     }
-  }
 
-  console.log('getSpanProcessors.length', result)
-  return result;
+    return result;
 }
 
 module.exports = {
-  getSpanProcessors,
+    getSpanProcessors,
 };

From 75cea924a6f8f6023117c37619a2497fd43781f8 Mon Sep 17 00:00:00 2001
From: David Luna <luna.bistuer@gmail.com>
Date: Mon, 23 Jun 2025 18:36:19 +0200
Subject: [PATCH 03/19] chore: add metrics and collect

---
 packages/opentelemetry-node/lib/processors.js | 64 +++++++++++++++++--
 1 file changed, 57 insertions(+), 7 deletions(-)

diff --git a/packages/opentelemetry-node/lib/processors.js b/packages/opentelemetry-node/lib/processors.js
index f2281c70..d82e02a1 100644
--- a/packages/opentelemetry-node/lib/processors.js
+++ b/packages/opentelemetry-node/lib/processors.js
@@ -8,6 +8,7 @@
 // - metric.otel.sdk.span.live.count
 // - metric.otel.sdk.span.ended.count
 
+const {metrics} = require('@opentelemetry/api');
 const {getStringListFromEnv, getStringFromEnv} = require('@opentelemetry/core');
 const {
     BatchSpanProcessor,
@@ -17,9 +18,10 @@ const {
 const {log} = require('./logging');
 
 /**
+ * @typedef {import('@opentelemetry/api').Meter} Meter
+ * @typedef {import('@opentelemetry/api').UpDownCounter} UpDownCounter
+ * @typedef {import('@opentelemetry/api').Counter} Counter
  * @typedef {import('@opentelemetry/sdk-trace-base').SpanProcessor} SpanProcessor
- */
-/**
  * @typedef {import('@opentelemetry/sdk-trace-base').SpanExporter} SpanExporter
  */
 
@@ -29,18 +31,66 @@ const otlpProtocol =
     getStringFromEnv('OTEL_EXPORTER_OTLP_PROTOCOL') ??
     'http/protobuf';
 
+// NOTE: assuming the meter provider is not going to be replaced once
+// the EDOT is started we can cache the meter and metrics in these vars
+/** @type {Meter} */
+let selfMetricsMeter;
+/** @type {UpDownCounter} */
+let liveSpans;
+/** @type {Counter} */
+let closedSpans;
+
+/**
+ * @returns {Meter}
+ */
+function getSpanMeter() {
+    if (selfMetricsMeter) {
+        return selfMetricsMeter;
+    }
+    // TODO: name & verison
+    selfMetricsMeter = metrics.getMeter('edot-nodejs', '1.2.3');
+    return selfMetricsMeter;
+}
+
+/**
+ * @returns {UpDownCounter}
+ */
+function getLiveSpans() {
+    if (liveSpans) {
+        return liveSpans;
+    }
+    liveSpans = getSpanMeter().createUpDownCounter('otel.sdk.span.live.count', {
+        description:
+            'Number of created spans for which the end operation has not been called yet',
+    });
+    return liveSpans;
+}
+
+/**
+ * @returns {Counter}
+ */
+function getClosedSpans() {
+    if (closedSpans) {
+        return closedSpans;
+    }
+    closedSpans = getSpanMeter().createCounter('otel.sdk.span.closed.count', {
+        description:
+            'Number of created spans for which the end operation was called',
+    });
+    return closedSpans;
+}
+
 /** @type {SpanProcessor} */
 const spanMetricsPrcessor = {
     forceFlush: function () {
         return Promise.resolve();
     },
     onStart: function (span, parentContext) {
-        // TODO:
-        // console.log('processor onStart');
+        getLiveSpans().add(1);
     },
     onEnd: function (span) {
-        // TODO: update metrics
-        // console.log('processor onEnd');
+        getLiveSpans().add(-1);
+        getClosedSpans().add(1);
     },
     shutdown: function () {
         // TODO: shutdown meter?
@@ -57,7 +107,7 @@ function getSpanExporter(type) {
         const {ZipkinExporter} = require('@opentelemetry/exporter-zipkin');
         return new ZipkinExporter();
     } else if (type === 'jaeger') {
-        // TODO: this shold be installed and there is a possible issue with bundlers. refs:
+        // TODO: this should be installed and there is a possible issue with bundlers. refs:
         // - is a dev-dependency? https://github.com/open-telemetry/opentelemetry-js/blob/ec17ce48d0e5a99a122da5add612a20e2dd84ed5/experimental/packages/opentelemetry-sdk-node/package.json#L76
         // - surreunded with try catch in https://github.com/open-telemetry/opentelemetry-js/blob/ec17ce48d0e5a99a122da5add612a20e2dd84ed5/experimental/packages/opentelemetry-sdk-node/src/utils.ts#L120
         // const {JaegerExporter} = require('@opentelemetry/exporter-jaeger');

From e584385038f26a6f5c0dec8e4bc57c27e8acec48 Mon Sep 17 00:00:00 2001
From: David Luna <luna.bistuer@gmail.com>
Date: Mon, 23 Jun 2025 19:30:38 +0200
Subject: [PATCH 04/19] chore: add types for processors.js file

---
 packages/opentelemetry-node/types/processors.d.ts | 9 +++++++++
 1 file changed, 9 insertions(+)
 create mode 100644 packages/opentelemetry-node/types/processors.d.ts

diff --git a/packages/opentelemetry-node/types/processors.d.ts b/packages/opentelemetry-node/types/processors.d.ts
new file mode 100644
index 00000000..71ced19c
--- /dev/null
+++ b/packages/opentelemetry-node/types/processors.d.ts
@@ -0,0 +1,9 @@
+export type Meter = import('@opentelemetry/api').Meter;
+export type UpDownCounter = import('@opentelemetry/api').UpDownCounter;
+export type Counter = import('@opentelemetry/api').Counter;
+export type SpanProcessor = import('@opentelemetry/sdk-trace-base').SpanProcessor;
+export type SpanExporter = import('@opentelemetry/sdk-trace-base').SpanExporter;
+/**
+ * @param {SpanProcessor[]} [processors]
+ */
+export function getSpanProcessors(processors?: SpanProcessor[]): import("@opentelemetry/sdk-trace-base").SpanProcessor[];

From e64765db44d72a908462e774897ceaf346d62e73 Mon Sep 17 00:00:00 2001
From: David Luna <luna.bistuer@gmail.com>
Date: Wed, 25 Jun 2025 10:22:35 +0200
Subject: [PATCH 05/19] chore: add test assertions for SDK span metrics

---
 packages/opentelemetry-node/lib/processors.js | 34 +++++++++++--------
 .../test/OTEL_METRICS_EXPORTER.test.js        |  3 ++
 2 files changed, 23 insertions(+), 14 deletions(-)

diff --git a/packages/opentelemetry-node/lib/processors.js b/packages/opentelemetry-node/lib/processors.js
index d82e02a1..092f27c7 100644
--- a/packages/opentelemetry-node/lib/processors.js
+++ b/packages/opentelemetry-node/lib/processors.js
@@ -25,6 +25,11 @@ const {log} = require('./logging');
  * @typedef {import('@opentelemetry/sdk-trace-base').SpanExporter} SpanExporter
  */
 
+// @ts-ignore - compiler options do not allow lookp outside `lib` folder
+const ELASTIC_PKG = require('../package.json');
+const ELASTIC_SDK_VERSION = ELASTIC_PKG.version;
+const ELASTIC_SDK_SCOPE = ELASTIC_PKG.name;
+
 const otlpPkgPreffix = '@opentelemetry/exporter-trace-otlp-';
 const otlpProtocol =
     getStringFromEnv('OTEL_EXPORTER_OTLP_TRACES_PROTOCOL') ??
@@ -43,37 +48,39 @@ let closedSpans;
 /**
  * @returns {Meter}
  */
-function getSpanMeter() {
+function getSpansMeter() {
     if (selfMetricsMeter) {
         return selfMetricsMeter;
     }
-    // TODO: name & verison
-    selfMetricsMeter = metrics.getMeter('edot-nodejs', '1.2.3');
+    selfMetricsMeter = metrics.getMeter(ELASTIC_SDK_SCOPE, ELASTIC_SDK_VERSION);
     return selfMetricsMeter;
 }
 
 /**
  * @returns {UpDownCounter}
  */
-function getLiveSpans() {
+function getLiveSpansCounter() {
     if (liveSpans) {
         return liveSpans;
     }
-    liveSpans = getSpanMeter().createUpDownCounter('otel.sdk.span.live.count', {
-        description:
-            'Number of created spans for which the end operation has not been called yet',
-    });
+    liveSpans = getSpansMeter().createUpDownCounter(
+        'otel.sdk.span.live.count',
+        {
+            description:
+                'Number of created spans for which the end operation has not been called yet',
+        }
+    );
     return liveSpans;
 }
 
 /**
  * @returns {Counter}
  */
-function getClosedSpans() {
+function getClosedSpansCounter() {
     if (closedSpans) {
         return closedSpans;
     }
-    closedSpans = getSpanMeter().createCounter('otel.sdk.span.closed.count', {
+    closedSpans = getSpansMeter().createCounter('otel.sdk.span.closed.count', {
         description:
             'Number of created spans for which the end operation was called',
     });
@@ -86,14 +93,13 @@ const spanMetricsPrcessor = {
         return Promise.resolve();
     },
     onStart: function (span, parentContext) {
-        getLiveSpans().add(1);
+        getLiveSpansCounter().add(1);
     },
     onEnd: function (span) {
-        getLiveSpans().add(-1);
-        getClosedSpans().add(1);
+        getLiveSpansCounter().add(-1);
+        getClosedSpansCounter().add(1);
     },
     shutdown: function () {
-        // TODO: shutdown meter?
         return Promise.resolve();
     },
 };
diff --git a/packages/opentelemetry-node/test/OTEL_METRICS_EXPORTER.test.js b/packages/opentelemetry-node/test/OTEL_METRICS_EXPORTER.test.js
index afbeec2e..c06324bf 100644
--- a/packages/opentelemetry-node/test/OTEL_METRICS_EXPORTER.test.js
+++ b/packages/opentelemetry-node/test/OTEL_METRICS_EXPORTER.test.js
@@ -34,6 +34,9 @@ const testFixtures = [
             t.ok(hasLog(`name: 'nodejs.eventloop.delay.min'`));
             t.ok(hasLog(`name: 'nodejs.eventloop.delay.max'`));
             t.ok(hasLog(`name: 'process.cpu.utilization'`));
+            t.ok(hasLog(`name: 'process.cpu.utilization'`));
+            t.ok(hasLog(`name: 'otel.sdk.span.live.count'`));
+            t.ok(hasLog(`name: 'otel.sdk.span.closed.count'`));
         },
         checkTelemetry: (t, col) => {
             t.ok(col.metrics.length > 0);

From 28573fa62432e98c38decd3a6a59ca457cb47a4c Mon Sep 17 00:00:00 2001
From: David Luna <luna.bistuer@gmail.com>
Date: Wed, 25 Jun 2025 11:09:38 +0200
Subject: [PATCH 06/19] chore: add tests for OTLP_TRACES_EXPORTER

---
 packages/opentelemetry-node/lib/processors.js |  3 +-
 .../test/OTEL_TRACES_EXPORTER.test.js         | 97 +++++++++++++++++++
 2 files changed, 99 insertions(+), 1 deletion(-)
 create mode 100644 packages/opentelemetry-node/test/OTEL_TRACES_EXPORTER.test.js

diff --git a/packages/opentelemetry-node/lib/processors.js b/packages/opentelemetry-node/lib/processors.js
index 092f27c7..8b2a579f 100644
--- a/packages/opentelemetry-node/lib/processors.js
+++ b/packages/opentelemetry-node/lib/processors.js
@@ -170,13 +170,14 @@ function getSpanProcessors(processors) {
     }
 
     if (exporters.length === 0) {
-        log.debug(
+        log.trace(
             'OTEL_TRACES_EXPORTER is empty. Using the default "otlp" exporter.'
         );
         exporters.push('otlp');
     }
 
     for (const name of exporters) {
+        log.trace(`Initializing "${name}" traces exporter.`);
         switch (name) {
             case 'otlp':
                 result.push(new BatchSpanProcessor(getSpanExporter('otlp')));
diff --git a/packages/opentelemetry-node/test/OTEL_TRACES_EXPORTER.test.js b/packages/opentelemetry-node/test/OTEL_TRACES_EXPORTER.test.js
new file mode 100644
index 00000000..717a3554
--- /dev/null
+++ b/packages/opentelemetry-node/test/OTEL_TRACES_EXPORTER.test.js
@@ -0,0 +1,97 @@
+/*
+ * Copyright Elasticsearch B.V. and contributors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+const {test} = require('tape');
+const {runTestFixtures} = require('./testutils');
+
+/** @type {import('./testutils').TestFixture[]} */
+const testFixtures = [
+    {
+        name: 'basic scenario with no values in env',
+        // Using an existing fixture since we're only interested in startup logs
+        // from the distro.
+        args: ['./fixtures/use-exporter-protocol.js'],
+        cwd: __dirname,
+        env: {
+            NODE_OPTIONS: '--import=@elastic/opentelemetry-node',
+            OTEL_LOG_LEVEL: 'verbose',
+        },
+        // verbose: true,
+        checkResult: (t, err, stdout, stderr) => {
+            t.error(err);
+            const lines = stdout.split('\n');
+            const hasLog = (text) =>
+                getLogs(lines).some((log) => log.msg.includes(text));
+            t.ok(hasLog('Initializing "otlp" traces exporter.'));
+            t.ok(!hasLog('Initializing "zipkin" traces exporter.'));
+            t.ok(!hasLog('Initializing "jaeger" traces exporter.'));
+            t.ok(!hasLog('Initializing "console" traces exporter.'));
+        },
+    },
+    {
+        name: 'scenario with "none" in OTEL_TRACES_EXPORTER',
+        // Using an existing fixture since we're only interested in startup logs
+        // from the distro.
+        args: ['./fixtures/use-exporter-protocol.js'],
+        cwd: __dirname,
+        env: {
+            NODE_OPTIONS: '--import=@elastic/opentelemetry-node',
+            OTEL_LOG_LEVEL: 'verbose',
+            OTEL_TRACES_EXPORTER: 'console, zipkin, otlp, none',
+        },
+        // verbose: true,
+        checkResult: (t, err, stdout, stderr) => {
+            t.error(err);
+            const lines = stdout.split('\n');
+            const hasLog = (text) =>
+                getLogs(lines).some((log) => log.msg.includes(text));
+            t.ok(hasLog('OTEL_TRACES_EXPORTER contains "none". No trace information or Spans will be exported.'));
+            t.ok(!hasLog('Initializing "otlp" traces exporter.'));
+            t.ok(!hasLog('Initializing "zipkin" traces exporter.'));
+            t.ok(!hasLog('Initializing "jaeger" traces exporter.'));
+            t.ok(!hasLog('Initializing "console" traces exporter.'));
+        },
+    },
+    {
+        name: 'scenario with values in OTEL_TRACES_EXPORTER',
+        // Using an existing fixture since we're only interested in startup logs
+        // from the distro.
+        args: ['./fixtures/use-exporter-protocol.js'],
+        cwd: __dirname,
+        env: {
+            NODE_OPTIONS: '--import=@elastic/opentelemetry-node',
+            OTEL_LOG_LEVEL: 'verbose',
+            OTEL_TRACES_EXPORTER: 'console, otlp',
+        },
+        // verbose: true,
+        checkResult: (t, err, stdout, stderr) => {
+            t.error(err);
+            const lines = stdout.split('\n');
+            const hasLog = (text) =>
+                getLogs(lines).some((log) => log.msg.includes(text));
+            t.ok(hasLog('Initializing "otlp" traces exporter.'));
+            t.ok(hasLog('Initializing "console" traces exporter.'));
+            t.ok(!hasLog('Initializing "zipkin" traces exporter.'));
+            t.ok(!hasLog('Initializing "jaeger" traces exporter.'));
+        },
+    },
+];
+
+// ----- helper functions -----
+
+/**
+ * @param {Array<string>} lines
+ * @returns {Array<{name: string, lelvel: number; msg: string}>}
+ */
+function getLogs(lines) {
+    return lines.filter((l) => l.startsWith('{')).map(JSON.parse);
+}
+
+// ----- main line -----
+
+test('OTEL_TRACES_EXPORTER', (suite) => {
+    runTestFixtures(suite, testFixtures);
+    suite.end();
+});

From 76363ee9aaefaa653f1cf77d84e324592c571c53 Mon Sep 17 00:00:00 2001
From: David Luna <luna.bistuer@gmail.com>
Date: Wed, 25 Jun 2025 11:09:57 +0200
Subject: [PATCH 07/19] chore: fix lint issues

---
 .../opentelemetry-node/test/OTEL_TRACES_EXPORTER.test.js    | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/packages/opentelemetry-node/test/OTEL_TRACES_EXPORTER.test.js b/packages/opentelemetry-node/test/OTEL_TRACES_EXPORTER.test.js
index 717a3554..57bf4fc4 100644
--- a/packages/opentelemetry-node/test/OTEL_TRACES_EXPORTER.test.js
+++ b/packages/opentelemetry-node/test/OTEL_TRACES_EXPORTER.test.js
@@ -47,7 +47,11 @@ const testFixtures = [
             const lines = stdout.split('\n');
             const hasLog = (text) =>
                 getLogs(lines).some((log) => log.msg.includes(text));
-            t.ok(hasLog('OTEL_TRACES_EXPORTER contains "none". No trace information or Spans will be exported.'));
+            t.ok(
+                hasLog(
+                    'OTEL_TRACES_EXPORTER contains "none". No trace information or Spans will be exported.'
+                )
+            );
             t.ok(!hasLog('Initializing "otlp" traces exporter.'));
             t.ok(!hasLog('Initializing "zipkin" traces exporter.'));
             t.ok(!hasLog('Initializing "jaeger" traces exporter.'));

From 59cb9ed241a7106f165c2d1cd32ccb5bcbc18352 Mon Sep 17 00:00:00 2001
From: David Luna <luna.bistuer@gmail.com>
Date: Wed, 25 Jun 2025 11:17:25 +0200
Subject: [PATCH 08/19] chore(otel-node): update package.json

---
 packages/opentelemetry-node/package-lock.json | 4 ++++
 packages/opentelemetry-node/package.json      | 4 ++++
 2 files changed, 8 insertions(+)

diff --git a/packages/opentelemetry-node/package-lock.json b/packages/opentelemetry-node/package-lock.json
index 1f97cbae..9045c0ae 100644
--- a/packages/opentelemetry-node/package-lock.json
+++ b/packages/opentelemetry-node/package-lock.json
@@ -18,6 +18,10 @@
         "@opentelemetry/exporter-metrics-otlp-grpc": "^0.202.0",
         "@opentelemetry/exporter-metrics-otlp-http": "^0.202.0",
         "@opentelemetry/exporter-metrics-otlp-proto": "^0.202.0",
+        "@opentelemetry/exporter-trace-otlp-grpc": "^0.202.0",
+        "@opentelemetry/exporter-trace-otlp-http": "^0.202.0",
+        "@opentelemetry/exporter-trace-otlp-proto": "^0.202.0",
+        "@opentelemetry/exporter-zipkin": "^2.0.1",
         "@opentelemetry/host-metrics": "^0.36.0",
         "@opentelemetry/instrumentation-amqplib": "^0.49.0",
         "@opentelemetry/instrumentation-aws-sdk": "^0.54.0",
diff --git a/packages/opentelemetry-node/package.json b/packages/opentelemetry-node/package.json
index 31a4b673..523f0b6b 100644
--- a/packages/opentelemetry-node/package.json
+++ b/packages/opentelemetry-node/package.json
@@ -81,6 +81,10 @@
     "@opentelemetry/exporter-metrics-otlp-grpc": "^0.202.0",
     "@opentelemetry/exporter-metrics-otlp-http": "^0.202.0",
     "@opentelemetry/exporter-metrics-otlp-proto": "^0.202.0",
+    "@opentelemetry/exporter-trace-otlp-grpc": "^0.202.0",
+    "@opentelemetry/exporter-trace-otlp-http": "^0.202.0",
+    "@opentelemetry/exporter-trace-otlp-proto": "^0.202.0",
+    "@opentelemetry/exporter-zipkin": "^2.0.1",
     "@opentelemetry/host-metrics": "^0.36.0",
     "@opentelemetry/instrumentation-amqplib": "^0.49.0",
     "@opentelemetry/instrumentation-aws-sdk": "^0.54.0",

From 942941c48201b366bce4870ad6038a3006e3450d Mon Sep 17 00:00:00 2001
From: David Luna <luna.bistuer@gmail.com>
Date: Wed, 25 Jun 2025 11:41:09 +0200
Subject: [PATCH 09/19] chore(otel-node): fix lint issues

---
 packages/opentelemetry-node/package-lock.json | 3 ---
 packages/opentelemetry-node/package.json      | 3 ---
 2 files changed, 6 deletions(-)

diff --git a/packages/opentelemetry-node/package-lock.json b/packages/opentelemetry-node/package-lock.json
index 9045c0ae..881f1146 100644
--- a/packages/opentelemetry-node/package-lock.json
+++ b/packages/opentelemetry-node/package-lock.json
@@ -18,9 +18,6 @@
         "@opentelemetry/exporter-metrics-otlp-grpc": "^0.202.0",
         "@opentelemetry/exporter-metrics-otlp-http": "^0.202.0",
         "@opentelemetry/exporter-metrics-otlp-proto": "^0.202.0",
-        "@opentelemetry/exporter-trace-otlp-grpc": "^0.202.0",
-        "@opentelemetry/exporter-trace-otlp-http": "^0.202.0",
-        "@opentelemetry/exporter-trace-otlp-proto": "^0.202.0",
         "@opentelemetry/exporter-zipkin": "^2.0.1",
         "@opentelemetry/host-metrics": "^0.36.0",
         "@opentelemetry/instrumentation-amqplib": "^0.49.0",
diff --git a/packages/opentelemetry-node/package.json b/packages/opentelemetry-node/package.json
index 523f0b6b..15eba1a2 100644
--- a/packages/opentelemetry-node/package.json
+++ b/packages/opentelemetry-node/package.json
@@ -81,9 +81,6 @@
     "@opentelemetry/exporter-metrics-otlp-grpc": "^0.202.0",
     "@opentelemetry/exporter-metrics-otlp-http": "^0.202.0",
     "@opentelemetry/exporter-metrics-otlp-proto": "^0.202.0",
-    "@opentelemetry/exporter-trace-otlp-grpc": "^0.202.0",
-    "@opentelemetry/exporter-trace-otlp-http": "^0.202.0",
-    "@opentelemetry/exporter-trace-otlp-proto": "^0.202.0",
     "@opentelemetry/exporter-zipkin": "^2.0.1",
     "@opentelemetry/host-metrics": "^0.36.0",
     "@opentelemetry/instrumentation-amqplib": "^0.49.0",

From 9fbe68480cda280fabc7e25057425c84a5b215ab Mon Sep 17 00:00:00 2001
From: David Luna <luna.bistuer@gmail.com>
Date: Wed, 25 Jun 2025 12:00:53 +0200
Subject: [PATCH 10/19] chore(otel-node): fix lint issues

---
 packages/opentelemetry-node/package-lock.json | 1 +
 packages/opentelemetry-node/package.json      | 1 +
 2 files changed, 2 insertions(+)

diff --git a/packages/opentelemetry-node/package-lock.json b/packages/opentelemetry-node/package-lock.json
index 881f1146..bfd29c62 100644
--- a/packages/opentelemetry-node/package-lock.json
+++ b/packages/opentelemetry-node/package-lock.json
@@ -67,6 +67,7 @@
         "@opentelemetry/sdk-logs": "^0.202.0",
         "@opentelemetry/sdk-metrics": "^2.0.0",
         "@opentelemetry/sdk-node": "^0.202.0",
+        "@opentelemetry/sdk-trace-base": "^2.0.1",
         "@opentelemetry/semantic-conventions": "^1.30.0",
         "@opentelemetry/winston-transport": "^0.13.0",
         "import-in-the-middle": "^1.12.0",
diff --git a/packages/opentelemetry-node/package.json b/packages/opentelemetry-node/package.json
index 15eba1a2..b5501442 100644
--- a/packages/opentelemetry-node/package.json
+++ b/packages/opentelemetry-node/package.json
@@ -130,6 +130,7 @@
     "@opentelemetry/sdk-logs": "^0.202.0",
     "@opentelemetry/sdk-metrics": "^2.0.0",
     "@opentelemetry/sdk-node": "^0.202.0",
+    "@opentelemetry/sdk-trace-base": "^2.0.1",
     "@opentelemetry/semantic-conventions": "^1.30.0",
     "@opentelemetry/winston-transport": "^0.13.0",
     "import-in-the-middle": "^1.12.0",

From ebd0802d5b66cbba9055fa98c6dca70a9441070b Mon Sep 17 00:00:00 2001
From: David Luna <luna.bistuer@gmail.com>
Date: Thu, 26 Jun 2025 09:30:16 +0200
Subject: [PATCH 11/19] chore: separate processors from SDK metrics

---
 packages/opentelemetry-node/lib/processors.js | 126 ++++------------
 .../opentelemetry-node/lib/sdk-metrics.js     | 138 ++++++++++++++++++
 packages/opentelemetry-node/lib/sdk.js        |   7 +-
 packages/opentelemetry-node/lib/semconv.js    |  49 ++++++-
 .../test/OTEL_METRICS_EXPORTER.test.js        |   4 +-
 .../test/OTEL_TRACES_EXPORTER.test.js         |  44 +++++-
 6 files changed, 259 insertions(+), 109 deletions(-)
 create mode 100644 packages/opentelemetry-node/lib/sdk-metrics.js

diff --git a/packages/opentelemetry-node/lib/processors.js b/packages/opentelemetry-node/lib/processors.js
index 8b2a579f..03db9093 100644
--- a/packages/opentelemetry-node/lib/processors.js
+++ b/packages/opentelemetry-node/lib/processors.js
@@ -4,11 +4,7 @@
  */
 
 // This replicates the SDKs logic of getting processors from env
-// and also adds a new one to collect span metrics like:
-// - metric.otel.sdk.span.live.count
-// - metric.otel.sdk.span.ended.count
 
-const {metrics} = require('@opentelemetry/api');
 const {getStringListFromEnv, getStringFromEnv} = require('@opentelemetry/core');
 const {
     BatchSpanProcessor,
@@ -18,92 +14,33 @@ const {
 const {log} = require('./logging');
 
 /**
- * @typedef {import('@opentelemetry/api').Meter} Meter
- * @typedef {import('@opentelemetry/api').UpDownCounter} UpDownCounter
- * @typedef {import('@opentelemetry/api').Counter} Counter
  * @typedef {import('@opentelemetry/sdk-trace-base').SpanProcessor} SpanProcessor
  * @typedef {import('@opentelemetry/sdk-trace-base').SpanExporter} SpanExporter
  */
 
-// @ts-ignore - compiler options do not allow lookp outside `lib` folder
-const ELASTIC_PKG = require('../package.json');
-const ELASTIC_SDK_VERSION = ELASTIC_PKG.version;
-const ELASTIC_SDK_SCOPE = ELASTIC_PKG.name;
-
-const otlpPkgPreffix = '@opentelemetry/exporter-trace-otlp-';
+const otlpPkgPrefix = '@opentelemetry/exporter-trace-otlp-';
 const otlpProtocol =
     getStringFromEnv('OTEL_EXPORTER_OTLP_TRACES_PROTOCOL') ??
     getStringFromEnv('OTEL_EXPORTER_OTLP_PROTOCOL') ??
     'http/protobuf';
 
-// NOTE: assuming the meter provider is not going to be replaced once
-// the EDOT is started we can cache the meter and metrics in these vars
-/** @type {Meter} */
-let selfMetricsMeter;
-/** @type {UpDownCounter} */
-let liveSpans;
-/** @type {Counter} */
-let closedSpans;
-
-/**
- * @returns {Meter}
- */
-function getSpansMeter() {
-    if (selfMetricsMeter) {
-        return selfMetricsMeter;
-    }
-    selfMetricsMeter = metrics.getMeter(ELASTIC_SDK_SCOPE, ELASTIC_SDK_VERSION);
-    return selfMetricsMeter;
-}
-
-/**
- * @returns {UpDownCounter}
- */
-function getLiveSpansCounter() {
-    if (liveSpans) {
-        return liveSpans;
-    }
-    liveSpans = getSpansMeter().createUpDownCounter(
-        'otel.sdk.span.live.count',
-        {
-            description:
-                'Number of created spans for which the end operation has not been called yet',
-        }
-    );
-    return liveSpans;
-}
-
-/**
- * @returns {Counter}
- */
-function getClosedSpansCounter() {
-    if (closedSpans) {
-        return closedSpans;
+// Jeager exporter is deprecated but upstream stills support it (for now)
+// ref: https://github.com/open-telemetry/opentelemetry-js/blob/main/experimental/CHANGELOG.md#0440
+function getJaegerExporter() {
+    // The JaegerExporter does not support being required in bundled
+    // environments. By delaying the require statement to here, we only crash when
+    // the exporter is actually used in such an environment.
+    try {
+        // @ts-ignore
+        const {JaegerExporter} = require('@opentelemetry/exporter-jaeger');
+        return new JaegerExporter();
+    } catch (e) {
+        throw new Error(
+            `Could not instantiate JaegerExporter. This could be due to the JaegerExporter's lack of support for bundling. If possible, use @opentelemetry/exporter-trace-otlp-proto instead. Original Error: ${e}`
+        );
     }
-    closedSpans = getSpansMeter().createCounter('otel.sdk.span.closed.count', {
-        description:
-            'Number of created spans for which the end operation was called',
-    });
-    return closedSpans;
 }
 
-/** @type {SpanProcessor} */
-const spanMetricsPrcessor = {
-    forceFlush: function () {
-        return Promise.resolve();
-    },
-    onStart: function (span, parentContext) {
-        getLiveSpansCounter().add(1);
-    },
-    onEnd: function (span) {
-        getLiveSpansCounter().add(-1);
-        getClosedSpansCounter().add(1);
-    },
-    shutdown: function () {
-        return Promise.resolve();
-    },
-};
-
 /**
  * @param {'otlp' | 'zipkin' | 'jaeger' | 'console'} type
  * @returns {SpanExporter}
@@ -122,7 +59,7 @@ function getSpanExporter(type) {
         return new ConsoleSpanExporter();
     }
 
-    let exporterPkgName = `${otlpPkgPreffix}`;
+    let exporterPkgName = `${otlpPkgPrefix}`;
     switch (otlpProtocol) {
         case 'grpc':
             exporterPkgName += 'grpc';
@@ -144,25 +81,14 @@ function getSpanExporter(type) {
 }
 
 /**
- * @param {SpanProcessor[]} [processors]
+ * @returns {SpanProcessor[]}
  */
-function getSpanProcessors(processors) {
-    const metricsExporters =
-        getStringListFromEnv('OTEL_METRICS_EXPORTER') || [];
-    const metricsEnabled = metricsExporters.every((e) => e !== 'none');
-
-    if (Array.isArray(processors)) {
-        if (metricsEnabled) {
-            processors.push(spanMetricsPrcessor);
-        }
-        return processors;
-    }
-
+function getSpanProcessors() {
     // Get from env
     const exporters = getStringListFromEnv('OTEL_TRACES_EXPORTER') ?? [];
-    const result = metricsEnabled ? [spanMetricsPrcessor] : [];
+    const result = [];
 
-    if (exporters.some((exp) => exp === 'none')) {
+    if (exporters[0] === 'none') {
         log.warn(
             'OTEL_TRACES_EXPORTER contains "none". No trace information or Spans will be exported.'
         );
@@ -174,6 +100,12 @@ function getSpanProcessors(processors) {
             'OTEL_TRACES_EXPORTER is empty. Using the default "otlp" exporter.'
         );
         exporters.push('otlp');
+    } else if (exporters.length > 1 && exporters.includes('none')) {
+        log.warn(
+            'OTEL_TRACES_EXPORTER contains "none" along with other exporters. Using default otlp exporter.'
+        );
+        exporters.length = 0;
+        exporters.push('otlp');
     }
 
     for (const name of exporters) {
@@ -191,11 +123,7 @@ function getSpanProcessors(processors) {
                 result.push(new BatchSpanProcessor(getSpanExporter('zipkin')));
                 break;
             case 'jaeger':
-                // TODO: check comment in `getSpanExporter` function
-                // result.push(new BatchSpanProcessor(getSpanExporter('zipkin')));
-                log.warn(
-                    `OTEL_TRACES_EXPORTER value "${name}" not available yet.`
-                );
+                result.push(new BatchSpanProcessor(getJaegerExporter()));
                 break;
             default:
                 log.warn(`Unrecognized OTEL_TRACES_EXPORTER value: ${name}.`);
diff --git a/packages/opentelemetry-node/lib/sdk-metrics.js b/packages/opentelemetry-node/lib/sdk-metrics.js
new file mode 100644
index 00000000..ff537667
--- /dev/null
+++ b/packages/opentelemetry-node/lib/sdk-metrics.js
@@ -0,0 +1,138 @@
+/*
+ * Copyright Elasticsearch B.V. and contributors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+// Gets the SDK configuration and updates it to have instruments
+// to collect metrics related to the SDK like:
+// - otel.sdk.span.live
+// - otel.sdk.span.ended
+
+const {metrics, TraceFlags} = require('@opentelemetry/api');
+const {
+    METRIC_OTEL_SDK_SPAN_ENDED,
+    METRIC_OTEL_SDK_SPAN_LIVE,
+    ATTR_OTEL_SPAN_SAMPLING_RESULT,
+    OTEL_SPAN_SAMPLING_RESULT_VALUE_DROP,
+    OTEL_SPAN_SAMPLING_RESULT_VALUE_RECORD_AND_SAMPLE,
+    OTEL_SPAN_SAMPLING_RESULT_VALUE_RECORD_ONLY,
+} = require('./semconv');
+
+/**
+ * @typedef {import('@opentelemetry/api').Meter} Meter
+ * @typedef {import('@opentelemetry/api').UpDownCounter} UpDownCounter
+ * @typedef {import('@opentelemetry/api').Counter} Counter
+ * @typedef {import('@opentelemetry/sdk-trace-base').SpanProcessor} SpanProcessor
+ */
+
+// @ts-ignore - compiler options do not allow lookp outside `lib` folder
+const ELASTIC_PKG = require('../package.json');
+const ELASTIC_SDK_VERSION = ELASTIC_PKG.version;
+const ELASTIC_SDK_SCOPE = ELASTIC_PKG.name;
+
+// NOTE: assuming the meter provider is not going to be replaced once
+// the EDOT is started we can cache the meter and metrics in these vars
+/** @type {Meter} */
+let selfMetricsMeter;
+/** @type {UpDownCounter} */
+let liveSpans;
+/** @type {Counter} */
+let closedSpans;
+
+/**
+ * @returns {Meter}
+ */
+function getSpansMeter() {
+    if (selfMetricsMeter) {
+        return selfMetricsMeter;
+    }
+    selfMetricsMeter = metrics.getMeter(ELASTIC_SDK_SCOPE, ELASTIC_SDK_VERSION);
+    return selfMetricsMeter;
+}
+
+/**
+ * @returns {UpDownCounter}
+ */
+function getLiveSpansCounter() {
+    if (liveSpans) {
+        return liveSpans;
+    }
+    liveSpans = getSpansMeter().createUpDownCounter(METRIC_OTEL_SDK_SPAN_LIVE, {
+        description:
+            'Number of created spans for which the end operation has not been called yet',
+    });
+    return liveSpans;
+}
+
+/**
+ * @returns {Counter}
+ */
+function getEndedSpansCounter() {
+    if (closedSpans) {
+        return closedSpans;
+    }
+    closedSpans = getSpansMeter().createCounter(METRIC_OTEL_SDK_SPAN_ENDED, {
+        description:
+            'Number of created spans for which the end operation was called',
+    });
+    return closedSpans;
+}
+
+/**
+ * @param {any} span - an Span form the API or a ReadableSpan from the trace SDK
+ * @returns {string}
+ */
+function getSamplingResult(span) {
+    let result;
+    const isRecording =
+        typeof span.isRecording === 'function'
+            ? span.isRecording()
+            : !span.ended;
+
+    if (isRecording) {
+        const isSampled = span.spanContext().traceFlags & TraceFlags.SAMPLED;
+        result = isSampled
+            ? OTEL_SPAN_SAMPLING_RESULT_VALUE_RECORD_AND_SAMPLE
+            : OTEL_SPAN_SAMPLING_RESULT_VALUE_RECORD_ONLY;
+    } else {
+        result = OTEL_SPAN_SAMPLING_RESULT_VALUE_DROP;
+    }
+
+    return result;
+}
+
+/** @type {SpanProcessor} */
+const spanMetricsProcessor = {
+    forceFlush: function () {
+        return Promise.resolve();
+    },
+    onStart: function (span, parentContext) {
+        getLiveSpansCounter().add(1, {
+            [ATTR_OTEL_SPAN_SAMPLING_RESULT]: getSamplingResult(span),
+        });
+    },
+    onEnd: function (span) {
+        getLiveSpansCounter().add(-1, {
+            [ATTR_OTEL_SPAN_SAMPLING_RESULT]: getSamplingResult(span),
+        });
+        getEndedSpansCounter().add(1, {
+            [ATTR_OTEL_SPAN_SAMPLING_RESULT]: getSamplingResult(span),
+        });
+    },
+    shutdown: function () {
+        return Promise.resolve();
+    },
+};
+
+/**
+ *
+ * @param {Partial<import('@opentelemetry/sdk-node').NodeSDKConfiguration>} cfg
+ * @returns
+ */
+function setupSdkMetrics(cfg) {
+    cfg.spanProcessors.push(spanMetricsProcessor);
+}
+
+module.exports = {
+    setupSdkMetrics,
+};
diff --git a/packages/opentelemetry-node/lib/sdk.js b/packages/opentelemetry-node/lib/sdk.js
index b97a6f2b..837b18d9 100644
--- a/packages/opentelemetry-node/lib/sdk.js
+++ b/packages/opentelemetry-node/lib/sdk.js
@@ -35,6 +35,7 @@ const {setupEnvironment, restoreEnvironment} = require('./environment');
 const {getInstrumentations} = require('./instrumentations');
 const {getSpanProcessors} = require('./processors');
 const {setupCentralConfig} = require('./central-config');
+const {setupSdkMetrics} = require('./sdk-metrics');
 const DISTRO_VERSION = require('../package.json').version;
 
 /**
@@ -125,7 +126,7 @@ function startNodeSDK(cfg = {}) {
     const defaultConfig = {
         resourceDetectors: resolveDetectors(cfg.resourceDetectors),
         instrumentations: cfg.instrumentations || getInstrumentations(),
-        spanProcessors: getSpanProcessors(cfg.spanProcessors),
+        spanProcessors: cfg.spanProcessors || getSpanProcessors(),
     };
 
     const exporterPkgNameFromEnvVar = {
@@ -194,6 +195,10 @@ function startNodeSDK(cfg = {}) {
                 aggregation: {type: AggregationType.DROP},
             },
         ];
+
+        // Configure OTEL SDK metrics
+        // ref: https://github.com/open-telemetry/semantic-conventions/blob/main/model/otel/metrics.yaml
+        setupSdkMetrics(defaultConfig);
     }
 
     const config = Object.assign(defaultConfig, cfg);
diff --git a/packages/opentelemetry-node/lib/semconv.js b/packages/opentelemetry-node/lib/semconv.js
index fe112210..16ca59f6 100644
--- a/packages/opentelemetry-node/lib/semconv.js
+++ b/packages/opentelemetry-node/lib/semconv.js
@@ -26,7 +26,6 @@
  * @experimental This attribute is experimental and is subject to breaking changes in minor releases of `@opentelemetry/semantic-conventions`.
  */
 const ATTR_DEPLOYMENT_ENVIRONMENT_NAME = 'deployment.environment.name';
-
 /**
  * The name of the deployment.
  *
@@ -37,7 +36,55 @@ const ATTR_DEPLOYMENT_ENVIRONMENT_NAME = 'deployment.environment.name';
  */
 const ATTR_DEPLOYMENT_NAME = 'deployment.name';
 
+/**
+ * The number of created spans for which the end operation was called
+ *
+ * @note For spans with `recording=true`: Implementations **MUST** record both `otel.sdk.span.live` and `otel.sdk.span.ended`.
+ * For spans with `recording=false`: If implementations decide to record this metric, they **MUST** also record `otel.sdk.span.live`.
+ *
+ * @experimental This metric is experimental and is subject to breaking changes in minor releases of `@opentelemetry/semantic-conventions`.
+ */
+const METRIC_OTEL_SDK_SPAN_ENDED = 'otel.sdk.span.ended';
+
+/**
+ * The number of created spans for which the end operation has not been called yet
+ *
+ * @note For spans with `recording=true`: Implementations **MUST** record both `otel.sdk.span.live` and `otel.sdk.span.ended`.
+ * For spans with `recording=false`: If implementations decide to record this metric, they **MUST** also record `otel.sdk.span.ended`.
+ *
+ * @experimental This metric is experimental and is subject to breaking changes in minor releases of `@opentelemetry/semantic-conventions`.
+ */
+const METRIC_OTEL_SDK_SPAN_LIVE = 'otel.sdk.span.live';
+
+/**
+ * The result value of the sampler for this span
+ *
+ * @experimental This attribute is experimental and is subject to breaking changes in minor releases of `@opentelemetry/semantic-conventions`.
+ */
+const ATTR_OTEL_SPAN_SAMPLING_RESULT = 'otel.span.sampling_result';
+
+/**
+ * Enum value "DROP" for attribute {@link ATTR_OTEL_SPAN_SAMPLING_RESULT}.
+ */
+const OTEL_SPAN_SAMPLING_RESULT_VALUE_DROP = 'DROP';
+
+/**
+ * Enum value "RECORD_AND_SAMPLE" for attribute {@link ATTR_OTEL_SPAN_SAMPLING_RESULT}.
+ */
+const OTEL_SPAN_SAMPLING_RESULT_VALUE_RECORD_AND_SAMPLE = 'RECORD_AND_SAMPLE';
+
+/**
+ * Enum value "RECORD_ONLY" for attribute {@link ATTR_OTEL_SPAN_SAMPLING_RESULT}.
+ */
+const OTEL_SPAN_SAMPLING_RESULT_VALUE_RECORD_ONLY = 'RECORD_ONLY';
+
 module.exports = {
     ATTR_DEPLOYMENT_ENVIRONMENT_NAME,
     ATTR_DEPLOYMENT_NAME,
+    METRIC_OTEL_SDK_SPAN_ENDED,
+    METRIC_OTEL_SDK_SPAN_LIVE,
+    ATTR_OTEL_SPAN_SAMPLING_RESULT,
+    OTEL_SPAN_SAMPLING_RESULT_VALUE_DROP,
+    OTEL_SPAN_SAMPLING_RESULT_VALUE_RECORD_AND_SAMPLE,
+    OTEL_SPAN_SAMPLING_RESULT_VALUE_RECORD_ONLY,
 };
diff --git a/packages/opentelemetry-node/test/OTEL_METRICS_EXPORTER.test.js b/packages/opentelemetry-node/test/OTEL_METRICS_EXPORTER.test.js
index c06324bf..e8f2b17b 100644
--- a/packages/opentelemetry-node/test/OTEL_METRICS_EXPORTER.test.js
+++ b/packages/opentelemetry-node/test/OTEL_METRICS_EXPORTER.test.js
@@ -35,8 +35,8 @@ const testFixtures = [
             t.ok(hasLog(`name: 'nodejs.eventloop.delay.max'`));
             t.ok(hasLog(`name: 'process.cpu.utilization'`));
             t.ok(hasLog(`name: 'process.cpu.utilization'`));
-            t.ok(hasLog(`name: 'otel.sdk.span.live.count'`));
-            t.ok(hasLog(`name: 'otel.sdk.span.closed.count'`));
+            t.ok(hasLog(`name: 'otel.sdk.span.live'`));
+            t.ok(hasLog(`name: 'otel.sdk.span.ended'`));
         },
         checkTelemetry: (t, col) => {
             t.ok(col.metrics.length > 0);
diff --git a/packages/opentelemetry-node/test/OTEL_TRACES_EXPORTER.test.js b/packages/opentelemetry-node/test/OTEL_TRACES_EXPORTER.test.js
index 57bf4fc4..24cf1043 100644
--- a/packages/opentelemetry-node/test/OTEL_TRACES_EXPORTER.test.js
+++ b/packages/opentelemetry-node/test/OTEL_TRACES_EXPORTER.test.js
@@ -3,6 +3,10 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
+// Test that the exporters and processors are properly set
+// via environment variables. thi test uses an existing fixture
+// since we're only interested in startup logs from the distro.
+
 const {test} = require('tape');
 const {runTestFixtures} = require('./testutils');
 
@@ -31,15 +35,16 @@ const testFixtures = [
         },
     },
     {
-        name: 'scenario with "none" in OTEL_TRACES_EXPORTER',
-        // Using an existing fixture since we're only interested in startup logs
-        // from the distro.
+        // NOTE: we believe the presence of "none" should disable all exporters
+        // (like metrics exporters) but this is not how the upstream SDK works.
+        // We keep behavior and will comment in the JS SIG
+        name: 'scenario with "none" in the 1st value of OTEL_TRACES_EXPORTER',
         args: ['./fixtures/use-exporter-protocol.js'],
         cwd: __dirname,
         env: {
             NODE_OPTIONS: '--import=@elastic/opentelemetry-node',
             OTEL_LOG_LEVEL: 'verbose',
-            OTEL_TRACES_EXPORTER: 'console, zipkin, otlp, none',
+            OTEL_TRACES_EXPORTER: 'none, console, zipkin, otlp',
         },
         // verbose: true,
         checkResult: (t, err, stdout, stderr) => {
@@ -58,10 +63,37 @@ const testFixtures = [
             t.ok(!hasLog('Initializing "console" traces exporter.'));
         },
     },
+    {
+        // NOTE: same here. The "none" value has a different effect when not in the
+        // 1st position of the list.
+        // ref: https://github.com/open-telemetry/opentelemetry-js/blob/main/experimental/packages/opentelemetry-sdk-node/src/utils.ts#L144-L162
+        name: 'scenario with "none" note in the 1st value of OTEL_TRACES_EXPORTER',
+        args: ['./fixtures/use-exporter-protocol.js'],
+        cwd: __dirname,
+        env: {
+            NODE_OPTIONS: '--import=@elastic/opentelemetry-node',
+            OTEL_LOG_LEVEL: 'verbose',
+            OTEL_TRACES_EXPORTER: 'console, zipkin, otlp, none',
+        },
+        // verbose: true,
+        checkResult: (t, err, stdout, stderr) => {
+            t.error(err);
+            const lines = stdout.split('\n');
+            const hasLog = (text) =>
+                getLogs(lines).some((log) => log.msg.includes(text));
+            t.ok(
+                hasLog(
+                    'OTEL_TRACES_EXPORTER contains "none" along with other exporters. Using default otlp exporter.'
+                )
+            );
+            t.ok(hasLog('Initializing "otlp" traces exporter.'));
+            t.ok(!hasLog('Initializing "zipkin" traces exporter.'));
+            t.ok(!hasLog('Initializing "jaeger" traces exporter.'));
+            t.ok(!hasLog('Initializing "console" traces exporter.'));
+        },
+    },
     {
         name: 'scenario with values in OTEL_TRACES_EXPORTER',
-        // Using an existing fixture since we're only interested in startup logs
-        // from the distro.
         args: ['./fixtures/use-exporter-protocol.js'],
         cwd: __dirname,
         env: {

From 35bcb2b2463715149a657d94e7993debaa1dcfcc Mon Sep 17 00:00:00 2001
From: David Luna <luna.bistuer@gmail.com>
Date: Thu, 26 Jun 2025 09:46:12 +0200
Subject: [PATCH 12/19] chore: update types

---
 .../opentelemetry-node/types/processors.d.ts  |  7 ++--
 .../opentelemetry-node/types/sdk-metrics.d.ts | 10 ++++++
 .../opentelemetry-node/types/semconv.d.ts     | 36 +++++++++++++++++++
 3 files changed, 48 insertions(+), 5 deletions(-)
 create mode 100644 packages/opentelemetry-node/types/sdk-metrics.d.ts

diff --git a/packages/opentelemetry-node/types/processors.d.ts b/packages/opentelemetry-node/types/processors.d.ts
index 71ced19c..6da2a935 100644
--- a/packages/opentelemetry-node/types/processors.d.ts
+++ b/packages/opentelemetry-node/types/processors.d.ts
@@ -1,9 +1,6 @@
-export type Meter = import('@opentelemetry/api').Meter;
-export type UpDownCounter = import('@opentelemetry/api').UpDownCounter;
-export type Counter = import('@opentelemetry/api').Counter;
 export type SpanProcessor = import('@opentelemetry/sdk-trace-base').SpanProcessor;
 export type SpanExporter = import('@opentelemetry/sdk-trace-base').SpanExporter;
 /**
- * @param {SpanProcessor[]} [processors]
+ * @returns {SpanProcessor[]}
  */
-export function getSpanProcessors(processors?: SpanProcessor[]): import("@opentelemetry/sdk-trace-base").SpanProcessor[];
+export function getSpanProcessors(): SpanProcessor[];
diff --git a/packages/opentelemetry-node/types/sdk-metrics.d.ts b/packages/opentelemetry-node/types/sdk-metrics.d.ts
new file mode 100644
index 00000000..6c32d2e4
--- /dev/null
+++ b/packages/opentelemetry-node/types/sdk-metrics.d.ts
@@ -0,0 +1,10 @@
+export type Meter = import('@opentelemetry/api').Meter;
+export type UpDownCounter = import('@opentelemetry/api').UpDownCounter;
+export type Counter = import('@opentelemetry/api').Counter;
+export type SpanProcessor = import('@opentelemetry/sdk-trace-base').SpanProcessor;
+/**
+ *
+ * @param {Partial<import('@opentelemetry/sdk-node').NodeSDKConfiguration>} cfg
+ * @returns
+ */
+export function setupSdkMetrics(cfg: Partial<import('@opentelemetry/sdk-node').NodeSDKConfiguration>): void;
diff --git a/packages/opentelemetry-node/types/semconv.d.ts b/packages/opentelemetry-node/types/semconv.d.ts
index 1ab1512a..89b695d6 100644
--- a/packages/opentelemetry-node/types/semconv.d.ts
+++ b/packages/opentelemetry-node/types/semconv.d.ts
@@ -24,3 +24,39 @@ export const ATTR_DEPLOYMENT_ENVIRONMENT_NAME: "deployment.environment.name";
  * @experimental This attribute is experimental and is subject to breaking changes in minor releases of `@opentelemetry/semantic-conventions`.
  */
 export const ATTR_DEPLOYMENT_NAME: "deployment.name";
+/**
+ * The number of created spans for which the end operation was called
+ *
+ * @note For spans with `recording=true`: Implementations **MUST** record both `otel.sdk.span.live` and `otel.sdk.span.ended`.
+ * For spans with `recording=false`: If implementations decide to record this metric, they **MUST** also record `otel.sdk.span.live`.
+ *
+ * @experimental This metric is experimental and is subject to breaking changes in minor releases of `@opentelemetry/semantic-conventions`.
+ */
+export const METRIC_OTEL_SDK_SPAN_ENDED: "otel.sdk.span.ended";
+/**
+ * The number of created spans for which the end operation has not been called yet
+ *
+ * @note For spans with `recording=true`: Implementations **MUST** record both `otel.sdk.span.live` and `otel.sdk.span.ended`.
+ * For spans with `recording=false`: If implementations decide to record this metric, they **MUST** also record `otel.sdk.span.ended`.
+ *
+ * @experimental This metric is experimental and is subject to breaking changes in minor releases of `@opentelemetry/semantic-conventions`.
+ */
+export const METRIC_OTEL_SDK_SPAN_LIVE: "otel.sdk.span.live";
+/**
+ * The result value of the sampler for this span
+ *
+ * @experimental This attribute is experimental and is subject to breaking changes in minor releases of `@opentelemetry/semantic-conventions`.
+ */
+export const ATTR_OTEL_SPAN_SAMPLING_RESULT: "otel.span.sampling_result";
+/**
+ * Enum value "DROP" for attribute {@link ATTR_OTEL_SPAN_SAMPLING_RESULT}.
+ */
+export const OTEL_SPAN_SAMPLING_RESULT_VALUE_DROP: "DROP";
+/**
+ * Enum value "RECORD_AND_SAMPLE" for attribute {@link ATTR_OTEL_SPAN_SAMPLING_RESULT}.
+ */
+export const OTEL_SPAN_SAMPLING_RESULT_VALUE_RECORD_AND_SAMPLE: "RECORD_AND_SAMPLE";
+/**
+ * Enum value "RECORD_ONLY" for attribute {@link ATTR_OTEL_SPAN_SAMPLING_RESULT}.
+ */
+export const OTEL_SPAN_SAMPLING_RESULT_VALUE_RECORD_ONLY: "RECORD_ONLY";

From a389f5c8c24c67069f21f2caf990328214cd591c Mon Sep 17 00:00:00 2001
From: David Luna <luna.bistuer@gmail.com>
Date: Thu, 26 Jun 2025 11:07:32 +0200
Subject: [PATCH 13/19] chore: ignore jaeger exporter from lint:deps

---
 packages/opentelemetry-node/package.json | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/opentelemetry-node/package.json b/packages/opentelemetry-node/package.json
index 81b459cc..71d44c82 100644
--- a/packages/opentelemetry-node/package.json
+++ b/packages/opentelemetry-node/package.json
@@ -47,7 +47,7 @@
     "lint:eslint": "eslint --ext=js,mjs,cjs . # requires node >=16.0.0",
     "lint:types": "rm -rf build/lint-types && tsc --outDir build/lint-types && diff -ur types build/lint-types",
     "lint:fix": "eslint --ext=js,mjs,cjs --fix . # requires node >=16.0.0",
-    "lint:deps": "dependency-check require.js import.mjs 'lib/**/*.js' 'test/**/*.js' '!test/fixtures/a-ts-proj' '!test/fixtures/an-esm-pkg' -e mjs:../../scripts/parse-mjs-source -i @types/tape -i dotenv -i @opentelemetry/winston-transport -i @opentelemetry/exporter-logs-* -i @opentelemetry/exporter-metrics-*",
+    "lint:deps": "dependency-check require.js import.mjs 'lib/**/*.js' 'test/**/*.js' '!test/fixtures/a-ts-proj' '!test/fixtures/an-esm-pkg' -e mjs:../../scripts/parse-mjs-source -i @types/tape -i dotenv -i @opentelemetry/winston-transport -i @opentelemetry/exporter-logs-* -i @opentelemetry/exporter-metrics-* -i @opentelemetry/exporter-jaeger",
     "lint:license-files": "../../scripts/gen-notice.sh --lint .  # requires node >=16",
     "lint:changelog": "../../scripts/extract-release-notes.js .",
     "test": "NODE_OPTIONS='-r dotenv/config' DOTENV_CONFIG_PATH=./test/test-services.env tape test/**/*.test.js",

From e25c31a7814962468599e1fe97dd6dfde72daf47 Mon Sep 17 00:00:00 2001
From: David Luna <luna.bistuer@gmail.com>
Date: Thu, 26 Jun 2025 20:21:29 +0200
Subject: [PATCH 14/19] chore(otel-node): fix samping result attribute

---
 .../opentelemetry-node/lib/sdk-metrics.js     | 42 ++++++++-----------
 packages/opentelemetry-node/lib/sdk.js        |  9 ++--
 packages/opentelemetry-node/lib/semconv.js    |  6 ---
 3 files changed, 22 insertions(+), 35 deletions(-)

diff --git a/packages/opentelemetry-node/lib/sdk-metrics.js b/packages/opentelemetry-node/lib/sdk-metrics.js
index ff537667..ad2888cc 100644
--- a/packages/opentelemetry-node/lib/sdk-metrics.js
+++ b/packages/opentelemetry-node/lib/sdk-metrics.js
@@ -4,7 +4,7 @@
  */
 
 // Gets the SDK configuration and updates it to have instruments
-// to collect metrics related to the SDK like:
+// to collect metrics related to the SDK, for now:
 // - otel.sdk.span.live
 // - otel.sdk.span.ended
 
@@ -13,7 +13,6 @@ const {
     METRIC_OTEL_SDK_SPAN_ENDED,
     METRIC_OTEL_SDK_SPAN_LIVE,
     ATTR_OTEL_SPAN_SAMPLING_RESULT,
-    OTEL_SPAN_SAMPLING_RESULT_VALUE_DROP,
     OTEL_SPAN_SAMPLING_RESULT_VALUE_RECORD_AND_SAMPLE,
     OTEL_SPAN_SAMPLING_RESULT_VALUE_RECORD_ONLY,
 } = require('./semconv');
@@ -22,6 +21,8 @@ const {
  * @typedef {import('@opentelemetry/api').Meter} Meter
  * @typedef {import('@opentelemetry/api').UpDownCounter} UpDownCounter
  * @typedef {import('@opentelemetry/api').Counter} Counter
+ * @typedef {import('@opentelemetry/sdk-trace-base').Span} Span
+ * @typedef {import('@opentelemetry/sdk-trace-base').ReadableSpan} ReadableSpan
  * @typedef {import('@opentelemetry/sdk-trace-base').SpanProcessor} SpanProcessor
  */
 
@@ -46,6 +47,8 @@ function getSpansMeter() {
     if (selfMetricsMeter) {
         return selfMetricsMeter;
     }
+    // NOTE: we have a metter for a single scope which is the EDOT package
+    // TODO: check WWJD (what would Java do?)
     selfMetricsMeter = metrics.getMeter(ELASTIC_SDK_SCOPE, ELASTIC_SDK_VERSION);
     return selfMetricsMeter;
 }
@@ -79,26 +82,16 @@ function getEndedSpansCounter() {
 }
 
 /**
- * @param {any} span - an Span form the API or a ReadableSpan from the trace SDK
+ * All Spans treated in SpanProcessors are recording so here none will have
+ * a "DROP" sampling result
+ * @param {Span | ReadableSpan} span
  * @returns {string}
  */
 function getSamplingResult(span) {
-    let result;
-    const isRecording =
-        typeof span.isRecording === 'function'
-            ? span.isRecording()
-            : !span.ended;
-
-    if (isRecording) {
-        const isSampled = span.spanContext().traceFlags & TraceFlags.SAMPLED;
-        result = isSampled
-            ? OTEL_SPAN_SAMPLING_RESULT_VALUE_RECORD_AND_SAMPLE
-            : OTEL_SPAN_SAMPLING_RESULT_VALUE_RECORD_ONLY;
-    } else {
-        result = OTEL_SPAN_SAMPLING_RESULT_VALUE_DROP;
-    }
-
-    return result;
+    const isSampled = span.spanContext().traceFlags & TraceFlags.SAMPLED;
+    return isSampled
+        ? OTEL_SPAN_SAMPLING_RESULT_VALUE_RECORD_AND_SAMPLE
+        : OTEL_SPAN_SAMPLING_RESULT_VALUE_RECORD_ONLY;
 }
 
 /** @type {SpanProcessor} */
@@ -106,18 +99,17 @@ const spanMetricsProcessor = {
     forceFlush: function () {
         return Promise.resolve();
     },
-    onStart: function (span, parentContext) {
+    onStart: function (span) {
         getLiveSpansCounter().add(1, {
             [ATTR_OTEL_SPAN_SAMPLING_RESULT]: getSamplingResult(span),
         });
     },
     onEnd: function (span) {
-        getLiveSpansCounter().add(-1, {
+        const attrs = {
             [ATTR_OTEL_SPAN_SAMPLING_RESULT]: getSamplingResult(span),
-        });
-        getEndedSpansCounter().add(1, {
-            [ATTR_OTEL_SPAN_SAMPLING_RESULT]: getSamplingResult(span),
-        });
+        };
+        getLiveSpansCounter().add(-1, attrs);
+        getEndedSpansCounter().add(1, attrs);
     },
     shutdown: function () {
         return Promise.resolve();
diff --git a/packages/opentelemetry-node/lib/sdk.js b/packages/opentelemetry-node/lib/sdk.js
index 837b18d9..a77891c0 100644
--- a/packages/opentelemetry-node/lib/sdk.js
+++ b/packages/opentelemetry-node/lib/sdk.js
@@ -195,15 +195,16 @@ function startNodeSDK(cfg = {}) {
                 aggregation: {type: AggregationType.DROP},
             },
         ];
-
-        // Configure OTEL SDK metrics
-        // ref: https://github.com/open-telemetry/semantic-conventions/blob/main/model/otel/metrics.yaml
-        setupSdkMetrics(defaultConfig);
     }
 
     const config = Object.assign(defaultConfig, cfg);
 
     setupEnvironment();
+    if (metricsEnabled) {
+        // Configure OTEL SDK metrics
+        // ref: https://github.com/open-telemetry/semantic-conventions/blob/main/model/otel/metrics.yaml
+        setupSdkMetrics(config);
+    }
     const sdk = new NodeSDK(config);
 
     // TODO perhaps include some choice resource attrs in this log (sync ones): service.name, deployment.environment.name
diff --git a/packages/opentelemetry-node/lib/semconv.js b/packages/opentelemetry-node/lib/semconv.js
index 16ca59f6..6912b50c 100644
--- a/packages/opentelemetry-node/lib/semconv.js
+++ b/packages/opentelemetry-node/lib/semconv.js
@@ -63,11 +63,6 @@ const METRIC_OTEL_SDK_SPAN_LIVE = 'otel.sdk.span.live';
  */
 const ATTR_OTEL_SPAN_SAMPLING_RESULT = 'otel.span.sampling_result';
 
-/**
- * Enum value "DROP" for attribute {@link ATTR_OTEL_SPAN_SAMPLING_RESULT}.
- */
-const OTEL_SPAN_SAMPLING_RESULT_VALUE_DROP = 'DROP';
-
 /**
  * Enum value "RECORD_AND_SAMPLE" for attribute {@link ATTR_OTEL_SPAN_SAMPLING_RESULT}.
  */
@@ -84,7 +79,6 @@ module.exports = {
     METRIC_OTEL_SDK_SPAN_ENDED,
     METRIC_OTEL_SDK_SPAN_LIVE,
     ATTR_OTEL_SPAN_SAMPLING_RESULT,
-    OTEL_SPAN_SAMPLING_RESULT_VALUE_DROP,
     OTEL_SPAN_SAMPLING_RESULT_VALUE_RECORD_AND_SAMPLE,
     OTEL_SPAN_SAMPLING_RESULT_VALUE_RECORD_ONLY,
 };

From d4b503c9598239dfbb7256728cec53ec4f3305ca Mon Sep 17 00:00:00 2001
From: David Luna <luna.bistuer@gmail.com>
Date: Fri, 27 Jun 2025 09:21:32 +0200
Subject: [PATCH 15/19] chore: fix metric attribs

---
 packages/opentelemetry-node/lib/processors.js      | 6 +-----
 packages/opentelemetry-node/types/sdk-metrics.d.ts | 2 ++
 packages/opentelemetry-node/types/semconv.d.ts     | 4 ----
 3 files changed, 3 insertions(+), 9 deletions(-)

diff --git a/packages/opentelemetry-node/lib/processors.js b/packages/opentelemetry-node/lib/processors.js
index 03db9093..c8524e01 100644
--- a/packages/opentelemetry-node/lib/processors.js
+++ b/packages/opentelemetry-node/lib/processors.js
@@ -50,11 +50,7 @@ function getSpanExporter(type) {
         const {ZipkinExporter} = require('@opentelemetry/exporter-zipkin');
         return new ZipkinExporter();
     } else if (type === 'jaeger') {
-        // TODO: this should be installed and there is a possible issue with bundlers. refs:
-        // - is a dev-dependency? https://github.com/open-telemetry/opentelemetry-js/blob/ec17ce48d0e5a99a122da5add612a20e2dd84ed5/experimental/packages/opentelemetry-sdk-node/package.json#L76
-        // - surreunded with try catch in https://github.com/open-telemetry/opentelemetry-js/blob/ec17ce48d0e5a99a122da5add612a20e2dd84ed5/experimental/packages/opentelemetry-sdk-node/src/utils.ts#L120
-        // const {JaegerExporter} = require('@opentelemetry/exporter-jaeger');
-        // result.push(new BatchSpanProcessor(new JaegerExporter()));
+        return getJaegerExporter();
     } else if (type === 'console') {
         return new ConsoleSpanExporter();
     }
diff --git a/packages/opentelemetry-node/types/sdk-metrics.d.ts b/packages/opentelemetry-node/types/sdk-metrics.d.ts
index 6c32d2e4..e3a62820 100644
--- a/packages/opentelemetry-node/types/sdk-metrics.d.ts
+++ b/packages/opentelemetry-node/types/sdk-metrics.d.ts
@@ -1,6 +1,8 @@
 export type Meter = import('@opentelemetry/api').Meter;
 export type UpDownCounter = import('@opentelemetry/api').UpDownCounter;
 export type Counter = import('@opentelemetry/api').Counter;
+export type Span = import('@opentelemetry/sdk-trace-base').Span;
+export type ReadableSpan = import('@opentelemetry/sdk-trace-base').ReadableSpan;
 export type SpanProcessor = import('@opentelemetry/sdk-trace-base').SpanProcessor;
 /**
  *
diff --git a/packages/opentelemetry-node/types/semconv.d.ts b/packages/opentelemetry-node/types/semconv.d.ts
index 89b695d6..e14e64f2 100644
--- a/packages/opentelemetry-node/types/semconv.d.ts
+++ b/packages/opentelemetry-node/types/semconv.d.ts
@@ -48,10 +48,6 @@ export const METRIC_OTEL_SDK_SPAN_LIVE: "otel.sdk.span.live";
  * @experimental This attribute is experimental and is subject to breaking changes in minor releases of `@opentelemetry/semantic-conventions`.
  */
 export const ATTR_OTEL_SPAN_SAMPLING_RESULT: "otel.span.sampling_result";
-/**
- * Enum value "DROP" for attribute {@link ATTR_OTEL_SPAN_SAMPLING_RESULT}.
- */
-export const OTEL_SPAN_SAMPLING_RESULT_VALUE_DROP: "DROP";
 /**
  * Enum value "RECORD_AND_SAMPLE" for attribute {@link ATTR_OTEL_SPAN_SAMPLING_RESULT}.
  */

From e82db6872dfa112d2eb8beafc48615fbd3e39630 Mon Sep 17 00:00:00 2001
From: David Luna <luna.bistuer@gmail.com>
Date: Fri, 27 Jun 2025 10:35:51 +0200
Subject: [PATCH 16/19] chore: add sdk metrics test

---
 .../test/OTEL_SDK_METRICS.test.js             | 82 +++++++++++++++++++
 1 file changed, 82 insertions(+)
 create mode 100644 packages/opentelemetry-node/test/OTEL_SDK_METRICS.test.js

diff --git a/packages/opentelemetry-node/test/OTEL_SDK_METRICS.test.js b/packages/opentelemetry-node/test/OTEL_SDK_METRICS.test.js
new file mode 100644
index 00000000..da0989dd
--- /dev/null
+++ b/packages/opentelemetry-node/test/OTEL_SDK_METRICS.test.js
@@ -0,0 +1,82 @@
+/*
+ * Copyright Elasticsearch B.V. and contributors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+const {test} = require('tape');
+const {runTestFixtures} = require('./testutils');
+
+/** @type {import('./testutils').TestFixture[]} */
+const testFixtures = [
+    {
+        name: 'basic scenario with no sampling configutarion involved (all spans sampled)',
+        args: ['./fixtures/use-http-server-metrics.js'],
+        cwd: __dirname,
+        env: {
+            NODE_OPTIONS: '--import=@elastic/opentelemetry-node',
+            OTEL_METRICS_EXPORTER: 'otlp,console',
+            // The default metrics interval is 30s, which makes for a slow test.
+            // However, too low a value runs into possible:
+            //      PeriodicExportingMetricReader: metrics collection errors TimeoutError: Operation timed out.
+            // which can lead to test data surprises.
+            OTEL_METRIC_EXPORT_INTERVAL: '1000',
+            OTEL_METRIC_EXPORT_TIMEOUT: '900',
+        },
+        // verbose: true,
+        checkResult: (t, err, stdout) => {
+            t.error(err);
+        },
+        checkTelemetry: (t, col) => {
+            t.ok(col.metrics.length > 0);
+
+            const spanMetrics = col.metrics.filter((m) =>
+                m.name.startsWith('otel.sdk.span')
+            );
+            t.ok(
+                spanMetrics.every((m) => {
+                    const dataPoints = m.sum.dataPoints;
+                    return dataPoints.every(
+                        (p) =>
+                            p.attributes['otel.span.sampling_result'] ===
+                            'RECORD_AND_SAMPLE'
+                    );
+                })
+            );
+        },
+    },
+    {
+        name: 'scenario with span sampling configuration involved (not sampling any spans)',
+        args: ['./fixtures/use-http-server-metrics.js'],
+        cwd: __dirname,
+        env: {
+            NODE_OPTIONS: '--import=@elastic/opentelemetry-node',
+            OTEL_METRICS_EXPORTER: 'otlp,console',
+            OTEL_TRACES_SAMPLER: 'always_off',
+            // The default metrics interval is 30s, which makes for a slow test.
+            // However, too low a value runs into possible:
+            //      PeriodicExportingMetricReader: metrics collection errors TimeoutError: Operation timed out.
+            // which can lead to test data surprises.
+            OTEL_METRIC_EXPORT_INTERVAL: '1000',
+            OTEL_METRIC_EXPORT_TIMEOUT: '900',
+        },
+        // verbose: true,
+        checkResult: (t, err, stdout) => {
+            t.error(err);
+        },
+        checkTelemetry: (t, col) => {
+            t.ok(col.metrics.length > 0);
+
+            const spanMetrics = col.metrics.filter((m) =>
+                m.name.startsWith('otel.sdk.span')
+            );
+            t.equal(spanMetrics.length, 0);
+        },
+    },
+];
+
+// ----- main line -----
+
+test('OTEL_SDK_METRICS', (suite) => {
+    runTestFixtures(suite, testFixtures);
+    suite.end();
+});

From e3f7ca0b2e72eabd2cef8a6d9520f4e470f796f4 Mon Sep 17 00:00:00 2001
From: David Luna <david.luna@elastic.co>
Date: Thu, 3 Jul 2025 09:54:55 +0200
Subject: [PATCH 17/19] Apply suggestions from code review

Co-authored-by: Trent Mick <trent.mick@elastic.co>
---
 packages/opentelemetry-node/lib/processors.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/opentelemetry-node/lib/processors.js b/packages/opentelemetry-node/lib/processors.js
index c8524e01..6cc3fffa 100644
--- a/packages/opentelemetry-node/lib/processors.js
+++ b/packages/opentelemetry-node/lib/processors.js
@@ -24,7 +24,7 @@ const otlpProtocol =
     getStringFromEnv('OTEL_EXPORTER_OTLP_PROTOCOL') ??
     'http/protobuf';
 
-// Jeager exporter is deprecated but upstream stills support it (for now)
+// Jaeger exporter is deprecated but upstream stills support it (for now)
 // ref: https://github.com/open-telemetry/opentelemetry-js/blob/main/experimental/CHANGELOG.md#0440
 function getJaegerExporter() {
     // The JaegerExporter does not support being required in bundled

From 001a8174b47ccfbc55a73e4d65484f8cdddfe88b Mon Sep 17 00:00:00 2001
From: David Luna <luna.bistuer@gmail.com>
Date: Thu, 3 Jul 2025 09:55:09 +0200
Subject: [PATCH 18/19] chore: rename test file and fix comments and typos

---
 packages/opentelemetry-node/lib/sdk-metrics.js        |  6 +++---
 packages/opentelemetry-node/lib/sdk.js                |  2 --
 .../test/OTEL_METRICS_EXPORTER.test.js                |  1 -
 .../{OTEL_SDK_METRICS.test.js => sdk-metrics.test.js} | 11 ++---------
 packages/opentelemetry-node/types/sdk-metrics.d.ts    |  3 ++-
 5 files changed, 7 insertions(+), 16 deletions(-)
 rename packages/opentelemetry-node/test/{OTEL_SDK_METRICS.test.js => sdk-metrics.test.js} (88%)

diff --git a/packages/opentelemetry-node/lib/sdk-metrics.js b/packages/opentelemetry-node/lib/sdk-metrics.js
index ad2888cc..e7326bf3 100644
--- a/packages/opentelemetry-node/lib/sdk-metrics.js
+++ b/packages/opentelemetry-node/lib/sdk-metrics.js
@@ -47,8 +47,7 @@ function getSpansMeter() {
     if (selfMetricsMeter) {
         return selfMetricsMeter;
     }
-    // NOTE: we have a metter for a single scope which is the EDOT package
-    // TODO: check WWJD (what would Java do?)
+    // NOTE: we have a meter for a single scope which is the EDOT package
     selfMetricsMeter = metrics.getMeter(ELASTIC_SDK_SCOPE, ELASTIC_SDK_VERSION);
     return selfMetricsMeter;
 }
@@ -117,7 +116,8 @@ const spanMetricsProcessor = {
 };
 
 /**
- *
+ * Updates the configuration to add OTEL SDK metrics
+ * ref: https://github.com/open-telemetry/semantic-conventions/blob/main/model/otel/metrics.yaml
  * @param {Partial<import('@opentelemetry/sdk-node').NodeSDKConfiguration>} cfg
  * @returns
  */
diff --git a/packages/opentelemetry-node/lib/sdk.js b/packages/opentelemetry-node/lib/sdk.js
index a77891c0..cf19a379 100644
--- a/packages/opentelemetry-node/lib/sdk.js
+++ b/packages/opentelemetry-node/lib/sdk.js
@@ -201,8 +201,6 @@ function startNodeSDK(cfg = {}) {
 
     setupEnvironment();
     if (metricsEnabled) {
-        // Configure OTEL SDK metrics
-        // ref: https://github.com/open-telemetry/semantic-conventions/blob/main/model/otel/metrics.yaml
         setupSdkMetrics(config);
     }
     const sdk = new NodeSDK(config);
diff --git a/packages/opentelemetry-node/test/OTEL_METRICS_EXPORTER.test.js b/packages/opentelemetry-node/test/OTEL_METRICS_EXPORTER.test.js
index e8f2b17b..bb4837cc 100644
--- a/packages/opentelemetry-node/test/OTEL_METRICS_EXPORTER.test.js
+++ b/packages/opentelemetry-node/test/OTEL_METRICS_EXPORTER.test.js
@@ -34,7 +34,6 @@ const testFixtures = [
             t.ok(hasLog(`name: 'nodejs.eventloop.delay.min'`));
             t.ok(hasLog(`name: 'nodejs.eventloop.delay.max'`));
             t.ok(hasLog(`name: 'process.cpu.utilization'`));
-            t.ok(hasLog(`name: 'process.cpu.utilization'`));
             t.ok(hasLog(`name: 'otel.sdk.span.live'`));
             t.ok(hasLog(`name: 'otel.sdk.span.ended'`));
         },
diff --git a/packages/opentelemetry-node/test/OTEL_SDK_METRICS.test.js b/packages/opentelemetry-node/test/sdk-metrics.test.js
similarity index 88%
rename from packages/opentelemetry-node/test/OTEL_SDK_METRICS.test.js
rename to packages/opentelemetry-node/test/sdk-metrics.test.js
index da0989dd..3433013f 100644
--- a/packages/opentelemetry-node/test/OTEL_SDK_METRICS.test.js
+++ b/packages/opentelemetry-node/test/sdk-metrics.test.js
@@ -9,12 +9,11 @@ const {runTestFixtures} = require('./testutils');
 /** @type {import('./testutils').TestFixture[]} */
 const testFixtures = [
     {
-        name: 'basic scenario with no sampling configutarion involved (all spans sampled)',
+        name: 'basic scenario with no sampling configuration involved (all spans sampled)',
         args: ['./fixtures/use-http-server-metrics.js'],
         cwd: __dirname,
         env: {
             NODE_OPTIONS: '--import=@elastic/opentelemetry-node',
-            OTEL_METRICS_EXPORTER: 'otlp,console',
             // The default metrics interval is 30s, which makes for a slow test.
             // However, too low a value runs into possible:
             //      PeriodicExportingMetricReader: metrics collection errors TimeoutError: Operation timed out.
@@ -23,15 +22,13 @@ const testFixtures = [
             OTEL_METRIC_EXPORT_TIMEOUT: '900',
         },
         // verbose: true,
-        checkResult: (t, err, stdout) => {
-            t.error(err);
-        },
         checkTelemetry: (t, col) => {
             t.ok(col.metrics.length > 0);
 
             const spanMetrics = col.metrics.filter((m) =>
                 m.name.startsWith('otel.sdk.span')
             );
+            t.ok(spanMetrics.length > 0);
             t.ok(
                 spanMetrics.every((m) => {
                     const dataPoints = m.sum.dataPoints;
@@ -50,7 +47,6 @@ const testFixtures = [
         cwd: __dirname,
         env: {
             NODE_OPTIONS: '--import=@elastic/opentelemetry-node',
-            OTEL_METRICS_EXPORTER: 'otlp,console',
             OTEL_TRACES_SAMPLER: 'always_off',
             // The default metrics interval is 30s, which makes for a slow test.
             // However, too low a value runs into possible:
@@ -60,9 +56,6 @@ const testFixtures = [
             OTEL_METRIC_EXPORT_TIMEOUT: '900',
         },
         // verbose: true,
-        checkResult: (t, err, stdout) => {
-            t.error(err);
-        },
         checkTelemetry: (t, col) => {
             t.ok(col.metrics.length > 0);
 
diff --git a/packages/opentelemetry-node/types/sdk-metrics.d.ts b/packages/opentelemetry-node/types/sdk-metrics.d.ts
index e3a62820..e1d844a7 100644
--- a/packages/opentelemetry-node/types/sdk-metrics.d.ts
+++ b/packages/opentelemetry-node/types/sdk-metrics.d.ts
@@ -5,7 +5,8 @@ export type Span = import('@opentelemetry/sdk-trace-base').Span;
 export type ReadableSpan = import('@opentelemetry/sdk-trace-base').ReadableSpan;
 export type SpanProcessor = import('@opentelemetry/sdk-trace-base').SpanProcessor;
 /**
- *
+ * Updates the configuration to add OTEL SDK metrics
+ * ref: https://github.com/open-telemetry/semantic-conventions/blob/main/model/otel/metrics.yaml
  * @param {Partial<import('@opentelemetry/sdk-node').NodeSDKConfiguration>} cfg
  * @returns
  */

From cebfcd03e6b39176e2fabec3a5ac088cfaad4f03 Mon Sep 17 00:00:00 2001
From: David Luna <david.luna@elastic.co>
Date: Fri, 4 Jul 2025 15:31:25 +0200
Subject: [PATCH 19/19] Update packages/opentelemetry-node/lib/processors.js

Co-authored-by: Trent Mick <trent.mick@elastic.co>
---
 packages/opentelemetry-node/lib/processors.js | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/packages/opentelemetry-node/lib/processors.js b/packages/opentelemetry-node/lib/processors.js
index 6cc3fffa..d4b857b0 100644
--- a/packages/opentelemetry-node/lib/processors.js
+++ b/packages/opentelemetry-node/lib/processors.js
@@ -3,7 +3,9 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
-// This replicates the SDKs logic of getting processors from env
+// This replicates the sdk-node logic of getting processors from env, because
+// the created NodeSDK doesn't expose the created processors and EDOT Node.js
+// wants to customize the default.
 
 const {getStringListFromEnv, getStringFromEnv} = require('@opentelemetry/core');
 const {