Semantic conventions for RocketMQ

Status: Development

The Semantic Conventions for Apache RocketMQ 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 as a comma-separated list of category-specific values (e.g., http, databases, messaging). 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.

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

Apache RocketMQ attributes

Specific attributes for Apache RocketMQ are defined below.

Attributes:

Key	Stability	Requirement Level	Value Type	Description	Example Values
messaging.consumer.group.name		Required	string	RocketMQ consumer group name.	my-group; indexer
messaging.operation.name		Required	string	The system-specific name of the messaging operation.	ack; nack; send
messaging.rocketmq.namespace		Required	string	Namespace of RocketMQ resources, resources in different namespaces are individual.	myNamespace
error.type		Conditionally Required If and only if the messaging operation has failed.	string	Describes a class of error the operation ended with. [1]	amqp:decode-error; KAFKA_STORAGE_ERROR; channel-error
messaging.batch.message_count		Conditionally Required [2]	int	The number of messages sent, received, or processed in the scope of the batching operation. [3]	0; 1; 2
messaging.destination.name		Conditionally Required [4]	string	The message destination name [5]	MyQueue; MyTopic
messaging.operation.type		Conditionally Required If applicable.	string	A string identifying the type of the messaging operation. [6]	create; send; receive
messaging.rocketmq.message.delay_time_level		Conditionally Required [7]	int	The delay time level for delay message, which determines the message delay time.	3
messaging.rocketmq.message.delivery_timestamp		Conditionally Required [8]	int	The timestamp in milliseconds that the delay message is expected to be delivered to consumer.	1665987217045
messaging.rocketmq.message.group		Conditionally Required If the message type is FIFO.	string	It is essential for FIFO message. Messages that belong to the same message group are always processed one by one within the same consumer group.	myMessageGroup
server.address		Conditionally Required If available.	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
messaging.client.id		Recommended	string	A unique identifier for the client that consumes or produces a message.	client-5; myhost@8742@s8083jm
messaging.message.id		Recommended If span describes operation on a single message.	string	A value used by the messaging system as an identifier for the message, represented as a string.	452a7c7c7c7048c2f887f61572b18fc2
messaging.rocketmq.consumption_model		Recommended	string	Model of message consumption. This only applies to consumer spans.	clustering; broadcasting
messaging.rocketmq.message.keys		Recommended	string[]	Key(s) of message, another way to mark message besides message id.	["keyA", "keyB"]
messaging.rocketmq.message.tag		Recommended	string	The secondary classifier of message besides topic.	tagA
messaging.rocketmq.message.type		Recommended	string	Type of message.	normal; fifo; delay
server.port		Recommended	int	Server port number. [10]	80; 8080; 443
messaging.message.body.size		Opt-In	int	The size of the message body in bytes. [11]	1439

[1] 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.

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

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

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

[7] messaging.rocketmq.message.delay_time_level: If the message type is delay and delivery timestamp is not specified.

[8] messaging.rocketmq.message.delivery_timestamp: If the message type is delay and delay time level is not specified.

[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.

[11] messaging.message.body.size: This can refer to both the compressed or uncompressed body size. If both sizes are known, the uncompressed body size should be used.

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.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.rocketmq.consumption_model 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
broadcasting	Broadcasting consumption model
clustering	Clustering consumption model

messaging.rocketmq.message.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
delay	Delay message
fifo	FIFO message
normal	Normal message
transaction	Transaction message

messaging.client.id SHOULD be set to the client ID that is automatically generated by the Apache RocketMQ SDK.