Semantic Conventions for Messaging Metrics

Status: Experimental

Common attributes

All messaging metrics share the same set of attributes:

[1]: The error.type SHOULD be predictable and SHOULD have low cardinality. 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]: If and only if the messaging operation has failed.

[3]: 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.

[4]: if and only if messaging.destination.name is known to have low cardinality. Otherwise, messaging.destination.template MAY be populated.

[5]: Destination names could be constructed from templates. An example would be a destination name involving a user name or product id. Although the destination name in this case is of high cardinality, the underlying template is of low cardinality and can be effectively used for grouping and aggregation.

[6]: The value SHOULD be normalized to lowercase.

[7]: network.protocol.version refers to the version of the protocol used and might be different from the protocol client’s version. If the HTTP client has a version of 0.27.2, but sends HTTP version 1.1, this attribute should be set to 1.1.

[8]: This should be the IP/hostname of the broker (or other network-level peer) this specific message is sent to/received from.

[9]: 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.

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.

messaging.system 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.

Producer metrics

Metric: messaging.publish.duration

This metric is required.

When this metric is reported alongside a messaging publish span, the metric value SHOULD be the same as the corresponding span duration.

This metric SHOULD be specified with ExplicitBucketBoundaries of [ 0.005, 0.01, 0.025, 0.05, 0.075, 0.1, 0.25, 0.5, 0.75, 1, 2.5, 5, 7.5, 10 ].

Metric: messaging.publish.messages

This metric is required when the messaging system supports batch publishing. It’s opt-in when the messaging system does not support batch publishing, since the message count can be derived from the messaging.publish.duration histogram.

The need to report messaging.publish.messages depends on the messaging system capabilities and not application scenarios or client library limitations. For example, RabbitMQ does not support batch publishing and corresponding instrumentations don’t need to report messaging.publish.messages. Kafka supports both, single and batch publishing, and instrumentations MUST report messaging.publish.messages counter regardless of application scenarios or APIs available in the client library.

Consumer metrics

Metric: messaging.receive.duration

This metric is required for operations that are initiated by the application code (pull-based).

This metric SHOULD be specified with ExplicitBucketBoundaries of [ 0.005, 0.01, 0.025, 0.05, 0.075, 0.1, 0.25, 0.5, 0.75, 1, 2.5, 5, 7.5, 10 ].

When this metric is reported alongside a messaging receive span, the metric value SHOULD be the same as the corresponding span duration.

Metric: messaging.receive.messages

This metric is required for batch receive operations. It’s opt-in when the messaging system does not support batch receive since the message count can be derived from the messaging.receive.duration histogram.

Note: The need to report messaging.receive.messages depends on the messaging system capabilities and not application scenarios or client library limitations.

Metric: messaging.deliver.duration

This metric is required for operations are not initiated by the application code (push-based deliver).

When this metric is reported alongside a messaging deliver span, the metric value SHOULD be the same as the corresponding span duration.

This metric SHOULD be specified with ExplicitBucketBoundaries of [ 0.005, 0.01, 0.025, 0.05, 0.075, 0.1, 0.25, 0.5, 0.75, 1, 2.5, 5, 7.5, 10 ].

Metric: messaging.deliver.messages

This metric is required for batch delivery operations. It’s opt-in when the messaging system does not support batch delivery since the message count can be derived from the messaging.deliver.duration histogram.

Note: The need to report messaging.deliver.messages depends on the messaging system capabilities and not application scenarios or client library limitations.