Semantic Conventions for CouchDB

Status: Experimental

The Semantic Conventions for CouchDB extend and override the Database Semantic Conventions.

Spans

Spans representing calls to CouchDB adhere to the general Semantic Conventions for Database Client Spans.

db.system.name MUST be set to "couchdb" and SHOULD be provided at span creation time.

The following table outlines the span attributes applicable to CouchDB.

Attribute	Type	Description	Examples	Requirement Level	Stability
db.namespace	string	The name of the database, fully qualified within the server address and port.	customers; test.users	Conditionally Required If available.
db.operation.name	string	The HTTP method + the target REST route. [1]	GET /{db}/{docid}	Conditionally Required If readily available.
db.response.status_code	string	The HTTP response code returned by the Couch DB recorded as a string. [2]	200; 201; 429	Conditionally Required [3]
error.type	string	Describes a class of error the operation ended with. [4]	timeout; java.net.UnknownHostException; server_certificate_invalid; 500	Conditionally Required If and only if the operation failed.
server.port	int	Server port number. [5]	80; 8080; 443	Conditionally Required [6]
db.operation.batch.size	int	The number of queries included in a batch operation. [7]	2; 3; 4	Recommended
server.address	string	Name of the database host. [8]	example.com; 10.1.2.80; /tmp/my.sock	Recommended

[1] db.operation.name: In CouchDB, db.operation.name should be set to the HTTP method + the target REST route according to the API reference documentation. For example, when retrieving a document, db.operation.name would be set to (literally, i.e., without replacing the placeholders with concrete values): GET /{db}/{docid}.

[2] db.response.status_code: HTTP response codes in the 4xx and 5xx range SHOULD be considered errors.

[3] db.response.status_code: If response was received and the HTTP response code is available.

[4] error.type: The error.type SHOULD match the db.response.status_code returned by the database or the client library, or the canonical name of exception that occurred. When using canonical exception type name, instrumentation SHOULD do the best effort to report the most relevant type. For example, if the original exception is wrapped into a generic one, the original exception SHOULD be preferred. Instrumentations SHOULD document how error.type is populated.

[5] 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.

[6] server.port: If using a port other than the default port for this DBMS and if server.address is set.

[7] db.operation.batch.size: Operations are only considered batches when they contain two or more operations, and so db.operation.batch.size SHOULD never be 1.

[8] server.address: When observed from the client side, and when communicating through an intermediary, server.address SHOULD represent the server address 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):

• db.namespace
• db.operation.name
• 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.

Metrics

CouchDB client instrumentations SHOULD collect metrics according to the general Semantic Conventions for Database Client Metrics.

db.system MUST be set to "couchdb".