Merge branch 'main' into cijothomas/knownbugtest

Author: cijothomas

.github/workflows/benchmark.yml

@@ -22,7 +22,10 @@ jobs:
     # If we're running on a PR, use ubuntu-latest - a shared runner. We can't use the self-hosted
     # runners on arbitrary PRs, and we don't want to unleash that load on the pool anyway.     
     # If we're running on main, use the OTEL self-hosted runner pool. 
-    runs-on: ${{ github.event_name == 'pull_request' && 'ubuntu-latest' || 'self-hosted' }}
+    
+    # TODO - temporarily move main to the shared workers, until we've resolved the instance setup issue
+    # runs-on: ${{ github.event_name == 'pull_request' && 'ubuntu-latest' || 'self-hosted' }}
+    runs-on: 'ubuntu-latest'
     if: ${{ (github.event_name == 'pull_request' && contains(github.event.pull_request.labels.*.name, 'performance')) || github.event_name == 'push' }}
     env:
       # For PRs, compare against the base branch - e.g., 'main'. 

.github/workflows/fossa.yml

@@ -14,7 +14,7 @@ jobs:
     steps:
       - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
 
-      - uses: fossas/fossa-action@93a52ecf7c3ac7eb40f5de77fd69b1a19524de94 # v1.5.0
+      - uses: fossas/fossa-action@c0a7d013f84c8ee5e910593186598625513cc1e4 # v1.6.0
         with:
           api-key: ${{secrets.FOSSA_API_KEY}}
           team: OpenTelemetry

.github/workflows/ossf-scorecard.yml

@@ -0,0 +1,47 @@
+name: OSSF Scorecard
+
+on:
+  push:
+    branches:
+      - main
+  schedule:
+    - cron: "50 3 * * 0" # once a week
+  workflow_dispatch:
+
+permissions: read-all
+
+jobs:
+  analysis:
+    runs-on: ubuntu-latest
+    permissions:
+      # Needed for Code scanning upload
+      security-events: write
+      # Needed for GitHub OIDC token if publish_results is true
+      id-token: write
+    steps:
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        with:
+          persist-credentials: false
+
+      - uses: ossf/scorecard-action@f49aabe0b5af0936a0987cfb85d86b75731b0186 # v2.4.1
+        with:
+          results_file: results.sarif
+          results_format: sarif
+          publish_results: true
+
+      # Upload the results as artifacts (optional). Commenting out will disable
+      # uploads of run results in SARIF format to the repository Actions tab.
+      # https://docs.github.com/en/actions/advanced-guides/storing-workflow-data-as-artifacts
+      - name: "Upload artifact"
+        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
+        with:
+          name: SARIF file
+          path: results.sarif
+          retention-days: 5
+
+      # Upload the results to GitHub's code scanning dashboard (optional).
+      # Commenting out will disable upload of results to your repo's Code Scanning dashboard
+      - name: "Upload to code-scanning"
+        uses: github/codeql-action/upload-sarif@1b549b9259bda1cb5ddde3b41741a82a2d15a841 # v3.28.13
+        with:
+          sarif_file: results.sarif

opentelemetry-otlp/src/metric.rs

@@ -21,6 +21,7 @@ use opentelemetry_sdk::metrics::{
     data::ResourceMetrics, exporter::PushMetricExporter, Temporality,
 };
 use std::fmt::{Debug, Formatter};
+use std::time::Duration;
 
 /// Target to which the exporter is going to send metrics, defaults to https://localhost:4317/v1/metrics.
 /// Learn about the relationship between this constant and default/spans/logs at
@@ -163,6 +164,10 @@ impl PushMetricExporter for MetricExporter {
     }
 
     fn shutdown(&self) -> OTelSdkResult {
+        self.shutdown_with_timeout(Duration::from_secs(5))
+    }
+
+    fn shutdown_with_timeout(&self, _timeout: std::time::Duration) -> OTelSdkResult {
         match &self.client {
             #[cfg(feature = "grpc-tonic")]
             SupportedTransportClient::Tonic(client) => client.shutdown(),

opentelemetry-sdk/CHANGELOG.md

@@ -12,6 +12,15 @@ the suppression flag in their dedicated thread, so that telemetry generated from
 those threads will not be fed back into OTel. Similarly, `SimpleLogProcessor`
 also modified to suppress telemetry before invoking exporters.
 
+- **Feature**: Implemented and enabled cardinality capping for Metrics by
+  default.  
+  - The default cardinality limit is 2000 and can be customized using Views.  
+  - This feature was previously removed in version 0.28 due to the lack of
+    configurability but has now been reintroduced with the ability to configure
+    the limit.  
+  - TODO/Placeholder: Add ability to configure cardinality limits via Instrument
+    advisory.
+
 ## 0.29.0
 
 Released 2025-Mar-21
@@ -68,6 +77,7 @@ Released 2025-Mar-21
 
   Custom exporters will need to internally synchronize any mutable state, if applicable.
 
+- **Breaking** The `shutdown_with_timeout` method is added to MetricExporter trait. This is breaking change for custom `MetricExporter` authors.
 - Bug Fix: `BatchLogProcessor` now correctly calls `shutdown` on the exporter
   when its `shutdown` is invoked.
 

opentelemetry-sdk/src/metrics/exporter.rs

@@ -1,5 +1,7 @@
 //! Interfaces for exporting metrics
+
 use crate::error::OTelSdkResult;
+use std::time::Duration;
 
 use crate::metrics::data::ResourceMetrics;
 
@@ -26,7 +28,12 @@ pub trait PushMetricExporter: Send + Sync + 'static {
     ///
     /// After Shutdown is called, calls to Export will perform no operation and
     /// instead will return an error indicating the shutdown state.
-    fn shutdown(&self) -> OTelSdkResult;
+    fn shutdown_with_timeout(&self, timeout: Duration) -> OTelSdkResult;
+
+    /// Shutdown with the default timeout of 5 seconds.
+    fn shutdown(&self) -> OTelSdkResult {
+        self.shutdown_with_timeout(Duration::from_secs(5))
+    }
 
     /// Access the [Temporality] of the MetricExporter.
     fn temporality(&self) -> Temporality;

opentelemetry-sdk/src/metrics/in_memory_exporter.rs

@@ -8,6 +8,7 @@ use crate::InMemoryExporterError;
 use std::collections::VecDeque;
 use std::fmt;
 use std::sync::{Arc, Mutex};
+use std::time::Duration;
 
 use super::data::{AggregatedMetrics, Metric, ScopeMetrics};
 
@@ -253,6 +254,10 @@ impl PushMetricExporter for InMemoryMetricExporter {
         Ok(())
     }
 
+    fn shutdown_with_timeout(&self, _timeout: Duration) -> OTelSdkResult {
+        Ok(())
+    }
+
     fn temporality(&self) -> Temporality {
         self.temporality
     }

opentelemetry-sdk/src/metrics/instrument.rs

@@ -130,10 +130,10 @@ impl Instrument {
 
     /// empty returns if all fields of i are their default-value.
     pub(crate) fn is_empty(&self) -> bool {
-        self.name == ""
-            && self.description == ""
+        self.name.is_empty()
+            && self.description.is_empty()
             && self.kind.is_none()
-            && self.unit == ""
+            && self.unit.is_empty()
             && self.scope == InstrumentationScope::default()
     }
 
@@ -203,6 +203,9 @@ pub struct Stream {
     /// dropped. If the set is empty, all attributes will be dropped, if `None` all
     /// attributes will be kept.
     pub allowed_attribute_keys: Option<Arc<HashSet<Key>>>,
+
+    /// Cardinality limit for the stream.
+    pub cardinality_limit: Option<usize>,
 }
 
 #[cfg(feature = "spec_unstable_metrics_views")]
@@ -245,6 +248,12 @@ impl Stream {
 
         self
     }
+
+    /// Set the stream cardinality limit.
+    pub fn cardinality_limit(mut self, limit: usize) -> Self {
+        self.cardinality_limit = Some(limit);
+        self
+    }
 }
 
 /// The identifying properties of an instrument.

opentelemetry-sdk/src/metrics/internal/aggregate.rs

@@ -15,16 +15,6 @@ use super::{
     precomputed_sum::PrecomputedSum, sum::Sum, Number,
 };
 
-pub(crate) const STREAM_CARDINALITY_LIMIT: usize = 2000;
-
-/// Checks whether aggregator has hit cardinality limit for metric streams
-pub(crate) fn is_under_cardinality_limit(_size: usize) -> bool {
-    true
-
-    // TODO: Implement this feature, after allowing the ability to customize the cardinality limit.
-    // size < STREAM_CARDINALITY_LIMIT
-}
-
 /// Receives measurements to be aggregated.
 pub(crate) trait Measure<T>: Send + Sync + 'static {
     fn call(&self, measurement: T, attrs: &[KeyValue]);
@@ -133,14 +123,22 @@ pub(crate) struct AggregateBuilder<T> {
     /// measurements.
     filter: AttributeSetFilter,
 
+    /// Cardinality limit for the metric stream
+    cardinality_limit: usize,
+
     _marker: marker::PhantomData<T>,
 }
 
 impl<T: Number> AggregateBuilder<T> {
-    pub(crate) fn new(temporality: Temporality, filter: Option<Filter>) -> Self {
+    pub(crate) fn new(
+        temporality: Temporality,
+        filter: Option<Filter>,
+        cardinality_limit: usize,
+    ) -> Self {
         AggregateBuilder {
             temporality,
             filter: AttributeSetFilter::new(filter),
+            cardinality_limit,
             _marker: marker::PhantomData,
         }
     }
@@ -150,18 +148,31 @@ impl<T: Number> AggregateBuilder<T> {
         LastValue::new(
             overwrite_temporality.unwrap_or(self.temporality),
             self.filter.clone(),
+            self.cardinality_limit,
         )
         .into()
     }
 
     /// Builds a precomputed sum aggregate function input and output.
     pub(crate) fn precomputed_sum(&self, monotonic: bool) -> AggregateFns<T> {
-        PrecomputedSum::new(self.temporality, self.filter.clone(), monotonic).into()
+        PrecomputedSum::new(
+            self.temporality,
+            self.filter.clone(),
+            monotonic,
+            self.cardinality_limit,
+        )
+        .into()
     }
 
     /// Builds a sum aggregate function input and output.
     pub(crate) fn sum(&self, monotonic: bool) -> AggregateFns<T> {
-        Sum::new(self.temporality, self.filter.clone(), monotonic).into()
+        Sum::new(
+            self.temporality,
+            self.filter.clone(),
+            monotonic,
+            self.cardinality_limit,
+        )
+        .into()
     }
 
     /// Builds a histogram aggregate function input and output.
@@ -177,6 +188,7 @@ impl<T: Number> AggregateBuilder<T> {
             boundaries,
             record_min_max,
             record_sum,
+            self.cardinality_limit,
         )
         .into()
     }
@@ -196,6 +208,7 @@ impl<T: Number> AggregateBuilder<T> {
             max_scale,
             record_min_max,
             record_sum,
+            self.cardinality_limit,
         )
         .into()
     }
@@ -211,10 +224,13 @@ mod tests {
 
     use super::*;
 
+    const CARDINALITY_LIMIT_DEFAULT: usize = 2000;
+
     #[test]
     fn last_value_aggregation() {
         let AggregateFns { measure, collect } =
-            AggregateBuilder::<u64>::new(Temporality::Cumulative, None).last_value(None);
+            AggregateBuilder::<u64>::new(Temporality::Cumulative, None, CARDINALITY_LIMIT_DEFAULT)
+                .last_value(None);
         let mut a = MetricData::Gauge(Gauge {
             data_points: vec![GaugeDataPoint {
                 attributes: vec![KeyValue::new("a", 1)],
@@ -244,7 +260,8 @@ mod tests {
     fn precomputed_sum_aggregation() {
         for temporality in [Temporality::Delta, Temporality::Cumulative] {
             let AggregateFns { measure, collect } =
-                AggregateBuilder::<u64>::new(temporality, None).precomputed_sum(true);
+                AggregateBuilder::<u64>::new(temporality, None, CARDINALITY_LIMIT_DEFAULT)
+                    .precomputed_sum(true);
             let mut a = MetricData::Sum(Sum {
                 data_points: vec![
                     SumDataPoint {
@@ -290,7 +307,8 @@ mod tests {
     fn sum_aggregation() {
         for temporality in [Temporality::Delta, Temporality::Cumulative] {
             let AggregateFns { measure, collect } =
-                AggregateBuilder::<u64>::new(temporality, None).sum(true);
+                AggregateBuilder::<u64>::new(temporality, None, CARDINALITY_LIMIT_DEFAULT)
+                    .sum(true);
             let mut a = MetricData::Sum(Sum {
                 data_points: vec![
                     SumDataPoint {
@@ -335,8 +353,9 @@ mod tests {
     #[test]
     fn explicit_bucket_histogram_aggregation() {
         for temporality in [Temporality::Delta, Temporality::Cumulative] {
-            let AggregateFns { measure, collect } = AggregateBuilder::<u64>::new(temporality, None)
-                .explicit_bucket_histogram(vec![1.0], true, true);
+            let AggregateFns { measure, collect } =
+                AggregateBuilder::<u64>::new(temporality, None, CARDINALITY_LIMIT_DEFAULT)
+                    .explicit_bucket_histogram(vec![1.0], true, true);
             let mut a = MetricData::Histogram(Histogram {
                 data_points: vec![HistogramDataPoint {
                     attributes: vec![KeyValue::new("a1", 1)],
@@ -382,8 +401,9 @@ mod tests {
     #[test]
     fn exponential_histogram_aggregation() {
         for temporality in [Temporality::Delta, Temporality::Cumulative] {
-            let AggregateFns { measure, collect } = AggregateBuilder::<u64>::new(temporality, None)
-                .exponential_bucket_histogram(4, 20, true, true);
+            let AggregateFns { measure, collect } =
+                AggregateBuilder::<u64>::new(temporality, None, CARDINALITY_LIMIT_DEFAULT)
+                    .exponential_bucket_histogram(4, 20, true, true);
             let mut a = MetricData::ExponentialHistogram(ExponentialHistogram {
                 data_points: vec![ExponentialHistogramDataPoint {
                     attributes: vec![KeyValue::new("a1", 1)],