Semantic conventions for CouchDB client operations

Status: Development

• Spans
• Metrics

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.

Status:

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.

Span name SHOULD follow the general database span name convention

Span kind SHOULD be CLIENT.

Span status SHOULD follow the Recording Errors document.

Attributes:

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

[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: If response was received and the HTTP response code is available.

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

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

[6] 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.

[7] db.operation.batch.size: Except for empty batch requests described below, a batch operation contains two or more database operations explicitly submitted as separate operations in a single client call, protocol message, or database command.

Requests to batch APIs that contain only one operation SHOULD be modeled as single operations, not as batch operations.

A database call is not a batch operation solely because one operation accepts multiple operands, such as keys, rows, documents, points, or other data elements, including Redis MGET with multiple keys.

In batch APIs that execute the same parameterized operation with parameter sets, each parameter set represents one database operation for determining whether the request is a batch operation. Requests with only one parameter set SHOULD be modeled as single operations, not as batch operations.

db.operation.batch.size SHOULD be set to the number of operations in the batch. It SHOULD NOT be set for non-batch operations.

A request to execute a batch operation with no operations SHOULD also be treated as a batch operation, and db.operation.batch.size SHOULD be set to 0.

[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.name MUST be set to "couchdb".