azure-messaging.md

Semantic Conventions for Azure Messaging Systems

Status: Experimental

The Semantic Conventions for Azure Service Bus and Azure Event Hubs extend and override the Messaging Semantic Conventions.

Warning

Existing messaging instrumentations that are using v1.24.0 of this document (or prior):

• SHOULD NOT change the version of the messaging conventions that they emit by default until the messaging semantic conventions are marked stable. Conventions include, but are not limited to, attributes, metric and span names, span kind and unit of measure.
• SHOULD introduce an environment variable OTEL_SEMCONV_STABILITY_OPT_IN in the existing major version which is a comma-separated list of values. The list of values includes:
  • messaging - emit the new, stable messaging conventions, and stop emitting the old experimental messaging conventions that the instrumentation emitted previously.
  • messaging/dup - emit both the old and the stable messaging conventions, allowing for a seamless transition.
  • The default behavior (in the absence of one of these values) is to continue emitting whatever version of the old experimental messaging conventions the instrumentation was emitting previously.
  • Note: messaging/dup has higher precedence than messaging in case both values are present
• SHOULD maintain (security patching at a minimum) the existing major version for at least six months after it starts emitting both sets of conventions.
• SHOULD drop the environment variable in the next major version.
• SHOULD emit the new, stable values for span name, span kind and similar "single" valued concepts when messaging/dup is present in the list.

Azure Service Bus

messaging.system MUST be set to "servicebus" and SHOULD be provided at span creation time.

Span attributes

The following additional attributes are defined:

Attribute	Type	Description	Examples	Requirement Level	Stability
messaging.operation.name	string	Azure Service Bus operation name. [1]	send; receive; complete; process; peek	Required
error.type	string	Describes a class of error the operation ended with. [2]	amqp:decode-error; KAFKA_STORAGE_ERROR; channel-error	Conditionally Required If and only if the messaging operation has failed.
messaging.batch.message_count	int	The number of messages sent, received, or processed in the scope of the batching operation. [3]	0; 1; 2	Conditionally Required [4]
messaging.destination.name	string	The message destination name [5]	MyQueue; MyTopic	Conditionally Required [6]
messaging.destination.subscription.name	string	Azure Service Bus subscription name.	subscription-a	Conditionally Required If messages are received from the subscription.
messaging.operation.type	string	A string identifying the type of the messaging operation. [7]	create; send; receive	Conditionally Required If applicable.
messaging.servicebus.disposition_status	string	Describes the settlement type.	complete; abandon; dead_letter	Conditionally Required if and only if messaging.operation is settle.
messaging.servicebus.message.delivery_count	int	Number of deliveries that have been attempted for this message.	2	Conditionally Required [8]
server.address	string	Server domain name if available without reverse DNS lookup; otherwise, IP address or Unix domain socket name. [9]	example.com; 10.1.2.80; /tmp/my.sock	Conditionally Required If available.
messaging.message.conversation_id	string	Message correlation Id property.	MyConversationId	Recommended
messaging.message.id	string	A value used by the messaging system as an identifier for the message, represented as a string.	452a7c7c7c7048c2f887f61572b18fc2	Recommended If span describes operation on a single message.
messaging.servicebus.message.enqueued_time	int	The UTC epoch seconds at which the message has been accepted and stored in the entity.	1701393730	Recommended
server.port	int	Server port number. [10]	80; 8080; 443	Recommended

[1] messaging.operation.name: The operation name SHOULD match one of the following values:

• sender operations: send, schedule, cancel_scheduled
• transaction operations: create_transaction, commit_transaction, rollback_transaction
• receiver operation: receive, peek, receive_deferred, renew_message_lock
• settlement operations: abandon, complete, defer, dead_letter, delete
• session operations: accept_session, get_session_state, set_session_state, renew_session_lock

If none of the above operation names apply, the attribute SHOULD be set to the name of the client method in snake_case.

[2] error.type: The error.type SHOULD be predictable, and SHOULD have low cardinality.

When error.type is set to a type (e.g., an exception type), its canonical class name identifying the type within the artifact SHOULD be used.

Instrumentations SHOULD document the list of errors they report.

The cardinality of error.type within one instrumentation library SHOULD be low. Telemetry consumers that aggregate data from multiple instrumentation libraries and applications should be prepared for error.type to have high cardinality at query time when no additional filters are applied.

If the operation has completed successfully, instrumentations SHOULD NOT set error.type.

If a specific domain defines its own set of error identifiers (such as HTTP or gRPC status codes), it's RECOMMENDED to:

• Use a domain-specific attribute
• Set error.type to capture all errors, regardless of whether they are defined within the domain-specific set or not.

[3] messaging.batch.message_count: Instrumentations SHOULD NOT set messaging.batch.message_count on spans that operate with a single message. When a messaging client library supports both batch and single-message API for the same operation, instrumentations SHOULD use messaging.batch.message_count for batching APIs and SHOULD NOT use it for single-message APIs.

[4] messaging.batch.message_count: If the span describes an operation on a batch of messages.

[5] messaging.destination.name: Destination name SHOULD uniquely identify a specific queue, topic or other entity within the broker. If the broker doesn't have such notion, the destination name SHOULD uniquely identify the broker.

[6] messaging.destination.name: If span describes operation on a single message or if the value applies to all messages in the batch.

[7] messaging.operation.type: If a custom value is used, it MUST be of low cardinality.

[8] messaging.servicebus.message.delivery_count: If delivery count is available and is bigger than 0.

[9] server.address: Server domain name of the broker if available without reverse DNS lookup; otherwise, IP address or Unix domain socket name.

[10] server.port: When observed from the client side, and when communicating through an intermediary, server.port SHOULD represent the server port behind any intermediaries, for example proxies, if it's available.

The following attributes can be important for making sampling decisions and SHOULD be provided at span creation time (if provided at all):

• messaging.destination.name
• messaging.destination.subscription.name
• messaging.operation.name
• messaging.operation.type
• server.address
• server.port

---

error.type has the following list of well-known values. If one of them applies, then the respective value MUST be used; otherwise, a custom value MAY be used.

Value	Description	Stability
_OTHER	A fallback error value to be used when the instrumentation doesn't define a custom value.

---

messaging.operation.type has the following list of well-known values. If one of them applies, then the respective value MUST be used; otherwise, a custom value MAY be used.

Value	Description	Stability
create	A message is created. "Create" spans always refer to a single message and are used to provide a unique creation context for messages in batch sending scenarios.
process	One or more messages are processed by a consumer.
receive	One or more messages are requested by a consumer. This operation refers to pull-based scenarios, where consumers explicitly call methods of messaging SDKs to receive messages.
send	One or more messages are provided for sending to an intermediary. If a single message is sent, the context of the "Send" span can be used as the creation context and no "Create" span needs to be created.
settle	One or more messages are settled.

---

messaging.servicebus.disposition_status has the following list of well-known values. If one of them applies, then the respective value MUST be used; otherwise, a custom value MAY be used.

Value	Description	Stability
abandon	Message is abandoned
complete	Message is completed
dead_letter	Message is sent to dead letter queue
defer	Message is deferred

Azure Event Hubs

messaging.system MUST be set to "eventhubs" and SHOULD be provided at span creation time.

Span attributes

The following additional attributes are defined:

Attribute	Type	Description	Examples	Requirement Level	Stability
messaging.operation.name	string	Azure Event Hubs operation name. [1]	send; receive; checkpoint	Required
error.type	string	Describes a class of error the operation ended with. [2]	amqp:decode-error; KAFKA_STORAGE_ERROR; channel-error	Conditionally Required If and only if the messaging operation has failed.
messaging.batch.message_count	int	The number of messages sent, received, or processed in the scope of the batching operation. [3]	0; 1; 2	Conditionally Required [4]
messaging.consumer.group.name	string	Azure Event Hubs consumer group name.	my-group; indexer	Conditionally Required On consumer spans.
messaging.destination.name	string	The message destination name [5]	MyQueue; MyTopic	Conditionally Required [6]
messaging.destination.partition.id	string	String representation of the partition id messages are sent to or received from, unique within the Event Hub.	1	Conditionally Required If available.
messaging.operation.type	string	A string identifying the type of the messaging operation. [7]	create; send; receive	Conditionally Required If applicable.
server.address	string	Server domain name if available without reverse DNS lookup; otherwise, IP address or Unix domain socket name. [8]	example.com; 10.1.2.80; /tmp/my.sock	Conditionally Required If available.
messaging.eventhubs.message.enqueued_time	int	The UTC epoch seconds at which the message has been accepted and stored in the entity.	1701393730	Recommended
messaging.message.id	string	A value used by the messaging system as an identifier for the message, represented as a string.	452a7c7c7c7048c2f887f61572b18fc2	Recommended If span describes operation on a single message.
server.port	int	Server port number. [9]	80; 8080; 443	Recommended

[1] messaging.operation.name: The operation name SHOULD match one of the following values:

• send
• receive
• process
• checkpoint
• get_partition_properties
• get_event_hub_properties

If none of the above operation names apply, the attribute SHOULD be set to the name of the client method in snake_case.

[2] error.type: The error.type SHOULD be predictable, and SHOULD have low cardinality.

When error.type is set to a type (e.g., an exception type), its canonical class name identifying the type within the artifact SHOULD be used.

Instrumentations SHOULD document the list of errors they report.

The cardinality of error.type within one instrumentation library SHOULD be low. Telemetry consumers that aggregate data from multiple instrumentation libraries and applications should be prepared for error.type to have high cardinality at query time when no additional filters are applied.

If the operation has completed successfully, instrumentations SHOULD NOT set error.type.

If a specific domain defines its own set of error identifiers (such as HTTP or gRPC status codes), it's RECOMMENDED to:

• Use a domain-specific attribute
• Set error.type to capture all errors, regardless of whether they are defined within the domain-specific set or not.

[3] messaging.batch.message_count: Instrumentations SHOULD NOT set messaging.batch.message_count on spans that operate with a single message. When a messaging client library supports both batch and single-message API for the same operation, instrumentations SHOULD use messaging.batch.message_count for batching APIs and SHOULD NOT use it for single-message APIs.

[4] messaging.batch.message_count: If the span describes an operation on a batch of messages.

[5] messaging.destination.name: Destination name SHOULD uniquely identify a specific queue, topic or other entity within the broker. If the broker doesn't have such notion, the destination name SHOULD uniquely identify the broker.

[6] messaging.destination.name: If span describes operation on a single message or if the value applies to all messages in the batch.

[7] messaging.operation.type: If a custom value is used, it MUST be of low cardinality.

[8] server.address: Server domain name of the broker if available without reverse DNS lookup; otherwise, IP address or Unix domain socket name.

[9] server.port: When observed from the client side, and when communicating through an intermediary, server.port SHOULD represent the server port behind any intermediaries, for example proxies, if it's available.

The following attributes can be important for making sampling decisions and SHOULD be provided at span creation time (if provided at all):

• messaging.consumer.group.name
• messaging.destination.name
• messaging.destination.partition.id
• messaging.operation.name
• messaging.operation.type
• server.address
• server.port

---

error.type has the following list of well-known values. If one of them applies, then the respective value MUST be used; otherwise, a custom value MAY be used.

Value	Description	Stability
_OTHER	A fallback error value to be used when the instrumentation doesn't define a custom value.

---

messaging.operation.type has the following list of well-known values. If one of them applies, then the respective value MUST be used; otherwise, a custom value MAY be used.

Value	Description	Stability
create	A message is created. "Create" spans always refer to a single message and are used to provide a unique creation context for messages in batch sending scenarios.
process	One or more messages are processed by a consumer.
receive	One or more messages are requested by a consumer. This operation refers to pull-based scenarios, where consumers explicitly call methods of messaging SDKs to receive messages.
send	One or more messages are provided for sending to an intermediary. If a single message is sent, the context of the "Send" span can be used as the creation context and no "Create" span needs to be created.
settle	One or more messages are settled.