chore: env vars for span limit as per specification

packages/opentelemetry-core/src/utils/environment.ts

@@ -25,10 +25,16 @@ export interface ENVIRONMENT {
   OTEL_LOG_LEVEL?: LogLevel;
   OTEL_NO_PATCH_MODULES?: string;
   OTEL_SAMPLING_PROBABILITY?: number;
+  OTEL_SPAN_ATTRIBUTE_COUNT_LIMIT?: number;
+  OTEL_SPAN_EVENT_COUNT_LIMIT?: number;
+  OTEL_SPAN_LINK_COUNT_LIMIT?: number;
 }
 
 const ENVIRONMENT_NUMBERS: Partial<keyof ENVIRONMENT>[] = [
   'OTEL_SAMPLING_PROBABILITY',
+  'OTEL_SPAN_ATTRIBUTE_COUNT_LIMIT',
+  'OTEL_SPAN_EVENT_COUNT_LIMIT',
+  'OTEL_SPAN_LINK_COUNT_LIMIT',
 ];
 
 /**
@@ -38,6 +44,9 @@ export const DEFAULT_ENVIRONMENT: Required<ENVIRONMENT> = {
   OTEL_NO_PATCH_MODULES: '',
   OTEL_LOG_LEVEL: LogLevel.INFO,
   OTEL_SAMPLING_PROBABILITY: 1,
+  OTEL_SPAN_ATTRIBUTE_COUNT_LIMIT: 1000,
+  OTEL_SPAN_EVENT_COUNT_LIMIT: 1000,
+  OTEL_SPAN_LINK_COUNT_LIMIT: 1000,
 };
 
 /**
@@ -57,8 +66,15 @@ function parseNumber(
 ) {
   if (typeof values[name] !== 'undefined') {
     const value = Number(values[name] as string);
-    if (!isNaN(value) && value >= min && value <= max) {
-      environment[name] = value;
+
+    if (!isNaN(value)) {
+      if (value < min) {
+        environment[name] = min;
+      } else if (value > max) {
+        environment[name] = max;
+      } else {
+        environment[name] = value;
+      }
     }
   }
 }

packages/opentelemetry-core/test/utils/environment.test.ts

@@ -77,11 +77,31 @@ describe('environment', () => {
         OTEL_NO_PATCH_MODULES: 'a,b,c',
         OTEL_LOG_LEVEL: 'ERROR',
         OTEL_SAMPLING_PROBABILITY: '0.5',
+        OTEL_SPAN_ATTRIBUTE_COUNT_LIMIT: 10,
+        OTEL_SPAN_EVENT_COUNT_LIMIT: 20,
+        OTEL_SPAN_LINK_COUNT_LIMIT: 30,
       });
       const env = getEnv();
       assert.strictEqual(env.OTEL_NO_PATCH_MODULES, 'a,b,c');
       assert.strictEqual(env.OTEL_LOG_LEVEL, LogLevel.ERROR);
       assert.strictEqual(env.OTEL_SAMPLING_PROBABILITY, 0.5);
+      assert.strictEqual(env.OTEL_SPAN_ATTRIBUTE_COUNT_LIMIT, 10);
+      assert.strictEqual(env.OTEL_SPAN_EVENT_COUNT_LIMIT, 20);
+      assert.strictEqual(env.OTEL_SPAN_LINK_COUNT_LIMIT, 30);
+    });
+
+    it('should match invalid values to closest valid equivalent', () => {
+      mockEnvironment({
+        OTEL_SAMPLING_PROBABILITY: '-0.1',
+      });
+      const minEnv = getEnv();
+      assert.strictEqual(minEnv.OTEL_SAMPLING_PROBABILITY, 0);
+
+      mockEnvironment({
+        OTEL_SAMPLING_PROBABILITY: '1.1',
+      });
+      const maxEnv = getEnv();
+      assert.strictEqual(maxEnv.OTEL_SAMPLING_PROBABILITY, 1);
     });
 
     it('should parse OTEL_LOG_LEVEL despite casing', () => {

packages/opentelemetry-tracing/src/config.ts

@@ -16,13 +16,6 @@
 
 import { AlwaysOnSampler, getEnv } from '@opentelemetry/core';
 
-/** Default limit for Message events per span */
-export const DEFAULT_MAX_EVENTS_PER_SPAN = 128;
-/** Default limit for Attributes per span */
-export const DEFAULT_MAX_ATTRIBUTES_PER_SPAN = 32;
-/** Default limit for Links per span */
-export const DEFAULT_MAX_LINKS_PER_SPAN = 32;
-
 /**
  * Default configuration. For fields with primitive values, any user-provided
  * value will override the corresponding default value. For fields with
@@ -33,9 +26,9 @@ export const DEFAULT_CONFIG = {
   logLevel: getEnv().OTEL_LOG_LEVEL,
   sampler: new AlwaysOnSampler(),
   traceParams: {
-    numberOfAttributesPerSpan: DEFAULT_MAX_ATTRIBUTES_PER_SPAN,
-    numberOfLinksPerSpan: DEFAULT_MAX_LINKS_PER_SPAN,
-    numberOfEventsPerSpan: DEFAULT_MAX_EVENTS_PER_SPAN,
+    numberOfAttributesPerSpan: getEnv().OTEL_SPAN_ATTRIBUTE_COUNT_LIMIT,
+    numberOfLinksPerSpan: getEnv().OTEL_SPAN_LINK_COUNT_LIMIT,
+    numberOfEventsPerSpan: getEnv().OTEL_SPAN_EVENT_COUNT_LIMIT,
   },
   gracefulShutdown: true,
 };

packages/opentelemetry-tracing/src/utility.ts

@@ -14,12 +14,7 @@
  * limitations under the License.
  */
 
-import {
-  DEFAULT_CONFIG,
-  DEFAULT_MAX_ATTRIBUTES_PER_SPAN,
-  DEFAULT_MAX_EVENTS_PER_SPAN,
-  DEFAULT_MAX_LINKS_PER_SPAN,
-} from './config';
+import { DEFAULT_CONFIG } from './config';
 import { TracerConfig } from './types';
 import {
   ParentBasedSampler,
@@ -32,10 +27,10 @@ import {
  * user provided configurations.
  */
 export function mergeConfig(userConfig: TracerConfig) {
-  const traceParams = userConfig.traceParams;
   const otelSamplingProbability = getEnv().OTEL_SAMPLING_PROBABILITY;
 
   const target = Object.assign(
+    {},
     DEFAULT_CONFIG,
     // use default AlwaysOnSampler if otelSamplingProbability is 1
     otelSamplingProbability !== undefined && otelSamplingProbability < 1
@@ -48,14 +43,11 @@ export function mergeConfig(userConfig: TracerConfig) {
     userConfig
   );
 
-  // the user-provided value will be used to extend the default value.
-  if (traceParams) {
-    target.traceParams.numberOfAttributesPerSpan =
-      traceParams.numberOfAttributesPerSpan || DEFAULT_MAX_ATTRIBUTES_PER_SPAN;
-    target.traceParams.numberOfEventsPerSpan =
-      traceParams.numberOfEventsPerSpan || DEFAULT_MAX_EVENTS_PER_SPAN;
-    target.traceParams.numberOfLinksPerSpan =
-      traceParams.numberOfLinksPerSpan || DEFAULT_MAX_LINKS_PER_SPAN;
-  }
+  target.traceParams = Object.assign(
+    {},
+    DEFAULT_CONFIG.traceParams,
+    userConfig.traceParams || {}
+  );
+
   return target;
 }

packages/opentelemetry-tracing/test/BasicTracerProvider.test.ts

@@ -75,9 +75,9 @@ describe('BasicTracerProvider', () => {
     it('should construct an instance with default trace params', () => {
       const tracer = new BasicTracerProvider({}).getTracer('default');
       assert.deepStrictEqual(tracer.getActiveTraceParams(), {
-        numberOfAttributesPerSpan: 32,
-        numberOfEventsPerSpan: 128,
-        numberOfLinksPerSpan: 32,
+        numberOfAttributesPerSpan: 1000,
+        numberOfEventsPerSpan: 1000,
+        numberOfLinksPerSpan: 1000,
       });
     });
 
@@ -89,8 +89,8 @@ describe('BasicTracerProvider', () => {
       }).getTracer('default');
       assert.deepStrictEqual(tracer.getActiveTraceParams(), {
         numberOfAttributesPerSpan: 100,
-        numberOfEventsPerSpan: 128,
-        numberOfLinksPerSpan: 32,
+        numberOfEventsPerSpan: 1000,
+        numberOfLinksPerSpan: 1000,
       });
     });
 
@@ -101,9 +101,9 @@ describe('BasicTracerProvider', () => {
         },
       }).getTracer('default');
       assert.deepStrictEqual(tracer.getActiveTraceParams(), {
-        numberOfAttributesPerSpan: 32,
+        numberOfAttributesPerSpan: 1000,
         numberOfEventsPerSpan: 300,
-        numberOfLinksPerSpan: 32,
+        numberOfLinksPerSpan: 1000,
       });
     });
 
@@ -114,8 +114,8 @@ describe('BasicTracerProvider', () => {
         },
       }).getTracer('default');
       assert.deepStrictEqual(tracer.getActiveTraceParams(), {
-        numberOfAttributesPerSpan: 32,
-        numberOfEventsPerSpan: 128,
+        numberOfAttributesPerSpan: 1000,
+        numberOfEventsPerSpan: 1000,
         numberOfLinksPerSpan: 10,
       });
     });

packages/opentelemetry-tracing/test/Span.test.ts

@@ -39,6 +39,10 @@ const performanceTimeOrigin = hrTime();
 describe('Span', () => {
   const tracer = new BasicTracerProvider({
     logger: new NoopLogger(),
+    traceParams: {
+      numberOfAttributesPerSpan: 100,
+      numberOfEventsPerSpan: 100,
+    },
   }).getTracer('default');
   const name = 'span1';
   const spanContext: SpanContext = {
@@ -327,7 +331,7 @@ describe('Span', () => {
     span.end();
   });
 
-  it('should drop extra links, attributes and events', () => {
+  it('should drop extra attributes and events', () => {
     const span = new Span(
       tracer,
       ROOT_CONTEXT,
@@ -341,8 +345,8 @@ describe('Span', () => {
     }
     span.end();
 
-    assert.strictEqual(span.events.length, 128);
-    assert.strictEqual(Object.keys(span.attributes).length, 32);
+    assert.strictEqual(span.events.length, 100);
+    assert.strictEqual(Object.keys(span.attributes).length, 100);
     assert.strictEqual(span.events[span.events.length - 1].name, 'sent149');
     assert.strictEqual(span.attributes['foo0'], undefined);
     assert.strictEqual(span.attributes['foo149'], 'bar149');