v1.40.0

🛑 Breaking changes 🛑

• db: Oracle's db.namespace updated to represent only the database’s
  unique identifier. Information previously bundled into db.namespace —including
  PDB name, instance name, and service name — has been moved to dedicated attributes:
  oracle.db.pdb, oracle.db.instance.name, and oracle.db.service.
  Introduced a new oracle.db.domain attribute to capture the database domain
  (DB_DOMAIN).
  (#2147)
• error, feature-flags: Deprecate error.message in favor of using domain-specific codes such as feature_flag.error.message.
  (#3307, #3308)
• rpc: Remove network.protocol.name, network.protocol.version, and network.transport attributes from RPC spans and metrics.
  (#3349, #3350)
• system: Rename system.memory.shared to system.memory.linux.shared (#3260)
  The system.memory.shared metric has been renamed to system.memory.linux.shared to align with other Linux-specific memory metrics (system.memory.linux.available and system.memory.linux.slab.usage). This metric reports shared memory used, primarily by tmpfs, and is only available on Linux systems.

🚩 Deprecations 🚩

• exceptions: Update exception recording guidelines to not use span events. (#3256)
• rpc: Deprecate experimental rpc.server.request.size, rpc.server.response.size, rpc.client.request.size, and rpc.client.response.size metrics due to ambiguous definitions and inconsistent implementation.
  (#3267)
• rpc: Deprecate the rpc.message event and its attributes (#3266, #3283)
  Per-message events within RPC streaming calls are of limited utility in their current form. They are recorded as span events (also being deprecated). There is no direct replacement at this time.

💡 Enhancements 💡

• cloud: Add oracle_cloud.realm vendor-specific attribute for Oracle Cloud Infrastructure (OCI) realm identifier. (#3121)
  An Oracle Cloud realm is a logical collection of cloud regions that are isolated from each other, used for compliance and data residency requirements.

• db: Mark the Oracle Database client span as Release Candidate. (#2989)

• db: Modify area to oracledb from oracle (#3316)

• db: Clarified db.query.summary behavior for batch operations. (#3287)

• db, rpc: Define domain-specific exception events for database and RPC (#3426)
  These domain-specific exception events provide a structured way to record
  exceptions that occur during operations in each area:

  • db.client.operation.exception for database client operations
  • rpc.client.call.exception and rpc.server.call.exception for RPC

• docs: Add how-to guide for defining spans (#3240)

• event: Allow event body to represent a display message. (#3343)

• exception: Indicate that exception.message attribute may contain sensitive information. (#2967, #3310)

• exceptions: Introduce OTEL_SEMCONV_EXCEPTION_SIGNAL_OPT_IN environment variable for transitioning exception recording from span events to logs. (#3363)

• gcp: Add GCP GCE Instance Group Manager attributes (#905)

• gen-ai: Add retrieval span support to the gen-ai semantic conventions. (#2907)

• gen-ai: Enhance how tool calls are captured to extend support for server side tools.
  (#2585)

• gen-ai: Add gen_ai.agent.version attribute to capture the version of an agent. (#3428)

• gen-ai: Add cache token attributes and provider-specific normalization guidance for GenAI usage metrics (#1959)

  • Add gen_ai.usage.cache_read.input_tokens attribute for tokens served from provider cache
  • Add gen_ai.usage.cache_creation.input_tokens attribute for tokens written to provider cache
  • Add provider-specific token handling notes to OpenAI span
  • Add Anthropic span with computation guidance for gen_ai.usage.input_tokens

• gen_ai: Added sampling-relevant flag to relevant GenAI span attributes to indicate their importance for sampling decisions. (#2994)

• http: Defined declarative configuration for overriding known HTTP methods. (#3394)

• http: Define declarative configuration for sensitive query parameters. (#3403)

• http: Define http.client.request.exception and http.server.request.exception events for recording exceptions during HTTP operations (#3414)
  These domain-specific exception events provide a structured way to record
  exceptions that occur during HTTP client requests (network failures, timeouts)
  and HTTP server request processing (application errors, internal failures).

• jvm: Add jvm.file_descriptor.limit as an in-development metric to track the maximum number of open file descriptors as reported by the JVM. (#3430)

• k8s: Promote a selection of k8s and container attributes to beta (#3120)

• k8s: Add k8s.service entity with endpoint and load balancer ingress metrics (#3294)
  New metrics:

  • k8s.service.endpoint.count: Number of endpoints by condition, address type, and zone
  • k8s.service.load_balancer.ingress.count: Number of load balancer ingress points
    New attributes:
  • k8s.service.endpoint.condition, k8s.service.endpoint.address_type, k8s.service.endpoint.zone
  • k8s.service.traffic_distribution, k8s.service.publish_not_ready_addresses
    New entity:
  • entity.k8s.service: k8s service entity with identifying and descriptive attributes

• openai: Add openai.api.type attribute to distinguish between different OpenAI API types for similar operations. (#3337)

• pprof: add pprof.scope.default_sample_type and pprof.scope.sample_type_order attributes to support lossless conversion of pprof profiles. (#3078)

• rpc: Mark core RPC (plus gRPC and Apache Dubbo) semantic conventions as release candidate. (#3446)

• rpc: Add Metrics sections to JSON-RPC, gRPC, and Connect RPC system-specific conventions (#3319, #3320)

• rpc: Change rpc.server.call.duration and rpc.client.call.duration metrics from recommended to required (#3284)

• rpc: Add RPC migration guide documenting changes from v1.37.0 to latest version. (#3204)

• rpc: Clarify that network.peer.address should indicate the last contacted address in case of retries.
  (#3392, #3427)

• rpc: Add semantic conventions for Apache Dubbo RPC system. (#3291)

• rpc: Clarify how to populate server.address and server.port when using client-side load balancing or service discovery.
  (#3258, #3317)

• service: Add service.criticality attribute to classify services based on operational importance (#2986)
  This attribute enables observability platforms to implement criticality-aware tracing, monitoring,
  and sampling strategies. Supports four levels: critical, high, medium, and low.

• service: Stabilize service.instance.id attribute. (#1519)
  The service.instance.id attribute and entity are promoted from development to stable.

• service: Stabilize service.namespace attribute. (#3254)
  The service.namespace attribute is promoted from development to stable.

New Contributors

• @osullivandonal made their first contribution in #3263
• @JWinermaSplunk made their first contribution in #2924
• @bachgarash made their first contribution in #3088
• @verdie-g made their first contribution in #3163
• @Arnav-Bansal made their first contribution in #3254
• @bidetofevil made their first contribution in #3387
• @aalexand made their first contribution in #3368

Full Changelog: v1.39.0...v1.40.0