Merge remote-tracking branch 'origin/main' into dependabot-auto-merge

Author: kimtore

docs/reference/observability/metrics/otel.md

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+# OpenTelemetry Metrics
+
+This is a list of metrics exported by the OpenTelemetry SDKs and auto-instrumentation libraries.
+
+## General Metrics
+
+The OpenTelemetry SDKs and auto-instrumentation libraries export the following general metrics:
+
+| Metric Name   | Description                                                                                            |
+| ------------- | ------------------------------------------------------------------------------------------------------ |
+| `target_info` | Information about the target service, such as the service name, service namespace, and container name. |
+
+## HTTP Server Metrics
+
+The OpenTelemetry SDKs and auto-instrumentation libraries export the following metrics for HTTP servers:
+
+| Metric Name                                | Description                                            |
+| ------------------------------------------ | ------------------------------------------------------ |
+| `http_server_duration_milliseconds_bucket` | Duration of HTTP server requests, in milliseconds.     |
+| `http_server_duration_milliseconds_count`  | Count of HTTP server requests, by duration.            |
+| `http_server_duration_milliseconds_sum`    | Sum of HTTP server request durations, in milliseconds. |
+
+## Database Client Connection Metrics
+
+The OpenTelemetry SDKs and auto-instrumentation libraries export the following metrics for database clients:
+
+| Metric Name                                             | Description                                                            |
+| ------------------------------------------------------- | ---------------------------------------------------------------------- |
+| `db_client_connections_create_time_milliseconds_bucket` | Duration of database client connection creation, in milliseconds.      |
+| `db_client_connections_create_time_milliseconds_count`  | Count of database client connection creations, by duration.            |
+| `db_client_connections_create_time_milliseconds_sum`    | Sum of database client connection creation durations, in milliseconds. |
+
+## JVM Metrics
+
+The OpenTelemetry SDKs and auto-instrumentation libraries export the following metrics for JVMs:
+
+| Metric Name                              | Description                          |
+| ---------------------------------------- | ------------------------------------ |
+| `process_runtime_jvm_buffer_count`       | Count of JVM buffers.                |
+| `process_runtime_jvm_buffer_limit_bytes` | Limit of JVM buffer sizes, in bytes. |
+| `process_runtime_jvm_buffer_usage_bytes` | Usage of JVM buffer sizes, in bytes. |
+
+## Kafka Metrics
+
+The OpenTelemetry SDKs and auto-instrumentation libraries export the following metrics for Kafka clients:
+
+| Metric Name        | Description                  |
+| ------------------ | ---------------------------- |
+| `kafka_producer_*` | Metrics for Kafka producers. |
+| `kafka_consumer_*` | Metrics for Kafka consumers. |