startSession

Definition

startSession

New in version 3.6.

The startSession command starts a new logical session for a sequence of operations.

Tip

In the mongo Shell, this command can also be run through the Mongo.startSession() helper method.

Helper methods are convenient for mongo users, but they may not return the same level of information as database commands. In cases where the convenience is not needed or the additional return fields are required, use the database command.

startSession has the following syntax:

{ startSession: 1 }

To run startSession, use the db.runCommand( { <command> } ) method.

db.runCommand( { startSession: 1 } )

Important

featureCompatibilityVersion must be 3.6 or greater to use the startSession command.

Tip

See also:

Mongo.startSession()

Behavior

If the deployment enforces authentication/authorization, you must be authenticated to run the startSession command. The user who runs startSession owns the created session, and only that user can use the session.

If the deployment does not enforce authentication/authorization, a created session has no owner and can be used by any user on any connection. If the user authenticates and creates a session for a deployment that does not enforce authentication/authorization, the user owns the session. However, any user on any connection may use the session.

If the deployment transitions to auth without any downtime, any sessions without an owner cannot be used.

Output

In addition to the status and operation time of the command, the startSession returns the following session specific information:

id: { id: <UUID> }