Semantic Conventions for MongoDB

Status: Experimental

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

Spans

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

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

The following table outlines the span attributes applicable to MongoDB.

Attributes

Attribute	Type	Description	Examples	Requirement Level	Stability
db.collection.name	string	The MongoDB collection being accessed within the database stated in db.namespace. [1]	public.users; customers	Required
db.namespace	string	The MongoDB database name.	customers; test.users	Conditionally Required If available.
db.operation.name	string	The name of the command being executed. [2]	findAndModify; getMore; update	Conditionally Required If readily available.
db.response.status_code	string	MongoDB error code represented as a string. [3]	36; 11602	Conditionally Required [4]
error.type	string	Describes a class of error the operation ended with. [5]	timeout; java.net.UnknownHostException; server_certificate_invalid; 500	Conditionally Required If and only if the operation failed.
server.port	int	Server port number. [6]	80; 8080; 443	Conditionally Required [7]
db.operation.batch.size	int	The number of queries included in a batch operation. [8]	2; 3; 4	Recommended
server.address	string	Name of the database host. [9]	example.com; 10.1.2.80; /tmp/my.sock	Recommended

[1] db.collection.name: It is RECOMMENDED to capture the value as provided by the application without attempting to do any case normalization.

The collection name SHOULD NOT be extracted from db.query.text, unless the query format is known to only ever have a single collection name present.

For batch operations, if the individual operations are known to have the same collection name then that collection name SHOULD be used.

[2] db.operation.name: See MongoDB database commands.

[3] db.response.status_code: All MongoDB error codes SHOULD be considered errors.

[4] db.response.status_code: If the operation failed and error code is available.

[5] 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.

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

[8] 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.

[9] 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.collection.name
• 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.

Example

Metrics

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

db.system MUST be set to "mongodb".