Merge branch 'main' into opentelemetrybot/auto-update-opentelemetry-collector-releases-v0.150.0

Author: tiffany76

content/en/docs/collector/configuration.md

@@ -371,7 +371,7 @@ processors:
       - key: email
         action: hash
 
-  # Data sources: metrics, metrics, logs
+  # Data sources: traces, metrics, logs
   filter:
     error_mode: ignore
     traces:

content/en/docs/demo/sample-configurations/_index.md

@@ -0,0 +1,9 @@
+---
+title: Sample Configurations
+---
+
+This section provides sample OpenTelemetry Collector configurations that
+demonstrate how to leverage resource attributes and processors available in the
+demo application.
+
+- [Tail-Based Sampling with `service.criticality`](tail-sampling-service-criticality/)

content/en/docs/demo/sample-configurations/tail-sampling-service-criticality.md

@@ -0,0 +1,137 @@
+---
+title: Tail-Based Sampling with service.criticality
+linkTitle: Tail Sampling
+---
+
+This example demonstrates how to use the
+[`service.criticality`](/docs/specs/semconv/resource/service/#service) resource
+attribute for intelligent tail-based sampling decisions in the OpenTelemetry
+Collector.
+
+The demo application assigns a `service.criticality` value to each service,
+classifying them by operational importance:
+
+| Criticality | Sampling Rate | Services                                                                                   |
+| ----------- | ------------- | ------------------------------------------------------------------------------------------ |
+| `critical`  | 100%          | payment, checkout, frontend, frontend-proxy                                                |
+| `high`      | 50%           | cart, product-catalog, currency, shipping                                                  |
+| `medium`    | 10%           | recommendation, ad, product-reviews, email                                                 |
+| `low`       | 1%            | accounting, fraud-detection, image-provider, load-generator, quote, flagd, flagd-ui, Kafka |
+
+## Collector Configuration
+
+To enable tail-based sampling, add the following to your
+`otelcol-config-extras.yml`:
+
+```yaml
+processors:
+  tail_sampling:
+    decision_wait: 10s
+    num_traces: 100000
+    expected_new_traces_per_sec: 1000
+    policies:
+      # Policy 1: Always sample critical services (100%)
+      - name: critical-services-always-sample
+        type: string_attribute
+        string_attribute:
+          key: service.criticality
+          values:
+            - critical
+          enabled_regex_matching: false
+          invert_match: false
+
+      # Policy 2: Sample 50% of high-criticality services
+      - name: high-criticality-probabilistic
+        type: and
+        and:
+          and_sub_policy:
+            - name: is-high-criticality
+              type: string_attribute
+              string_attribute:
+                key: service.criticality
+                values:
+                  - high
+            - name: probabilistic-50
+              type: probabilistic
+              probabilistic:
+                sampling_percentage: 50
+
+      # Policy 3: Sample 10% of medium-criticality services
+      - name: medium-criticality-probabilistic
+        type: and
+        and:
+          and_sub_policy:
+            - name: is-medium-criticality
+              type: string_attribute
+              string_attribute:
+                key: service.criticality
+                values:
+                  - medium
+            - name: probabilistic-10
+              type: probabilistic
+              probabilistic:
+                sampling_percentage: 10
+
+      # Policy 4: Sample 1% of low-criticality services
+      - name: low-criticality-probabilistic
+        type: and
+        and:
+          and_sub_policy:
+            - name: is-low-criticality
+              type: string_attribute
+              string_attribute:
+                key: service.criticality
+                values:
+                  - low
+            - name: probabilistic-1
+              type: probabilistic
+              probabilistic:
+                sampling_percentage: 1
+
+      # Policy 5: Always sample error traces regardless of criticality
+      - name: errors-always-sample
+        type: status_code
+        status_code:
+          status_codes:
+            - ERROR
+
+      # Policy 6: Always sample slow traces from critical/high services
+      - name: slow-critical-traces
+        type: and
+        and:
+          and_sub_policy:
+            - name: is-critical-or-high
+              type: string_attribute
+              string_attribute:
+                key: service.criticality
+                values:
+                  - critical
+                  - high
+            - name: is-slow
+              type: latency
+              latency:
+                threshold_ms: 5000
+
+service:
+  pipelines:
+    traces:
+      receivers: [otlp]
+      processors: [resourcedetection, memory_limiter, transform, tail_sampling]
+      exporters: [otlp, debug, spanmetrics]
+```
+
+## How It Works
+
+The tail-sampling processor evaluates completed traces against the configured
+policies. A trace is sampled if **any** policy matches:
+
+- **Critical services** are always sampled to ensure full visibility into
+  payment flows, checkout, and user-facing services.
+- **High-criticality services** are sampled at 50%, balancing observability with
+  data volume.
+- **Medium and low-criticality services** are progressively sampled at lower
+  rates to reduce noise from less critical paths.
+- **Errors are always captured** regardless of service criticality, ensuring no
+  issues go unnoticed.
+- **Slow traces** (>5s) from critical and high-criticality services are always
+  sampled to help identify performance bottlenecks.