$listLocalSessions¶

Definition定义¶

$listLocalSessions¶

New in version 3.6.版本3.6中的新功能。

Lists the sessions cached in memory by the mongod or mongos instance.列出mongod或mongos实例缓存在内存中的会话。

Important

When a user creates a session on a mongod or mongos instance, the record of the session initially exists only in-memory on the instance; i.e. the record is local to the instance. 当用户在mongod或mongos实例上创建会话时，会话记录最初仅存在于实例的内存中；亦即，记录是实例的本地记录。Periodically, the instance will sync its cached sessions to the system.sessions collection in the config database, at which time, they are visible to $listSessions and all members of the deployment. 实例将定期将其缓存的会话同步到config数据库的system.sessions集合中，此时，$listSessions和部署的所有成员都可以看到它们。Until the session record exists in the system.sessions collection, you can only list the session via the $listLocalSessions operation.除非system.sessions集合中存在会话记录，否则只能通过$listLocalSessions操作列出会话。

The $listLocalSessions operation uses the db.aggregate() method and not the db.collection.aggregate().$listLocalSessions操作使用db.aggregate()方法，而不是db.collection.aggregate()方法。

To run $listLocalSessions, it must be the first stage in the pipeline.要运行$listLocalSessions，它必须是管道中的第一个阶段。

The stage has the following syntax:语法如下所示：

{ $listLocalSessions: <document> }

The $listLocalSessions stage takes a document with one of the following contents:$listLocalSessions阶段接收包含以下内容之一的文档：

{ }	If running with access control, returns all sessions for the current authenticated user.如果使用访问控制运行，则返回当前已验证用户的所有会话。 If running without access control, returns all sessions.如果在没有访问控制的情况下运行，则返回所有会话。
{ users: [ { user: <user>, db: <db> }, ... ] }	Returns all sessions for the specified users. 返回指定用户的所有会话。If running with access control, the authenticated user must have privileges with listSession action on the cluster to list sessions for other users.如果使用访问控制运行，经过身份验证的用户必须具有在群集上执行listSession操作的权限，才能列出其他用户的会话。
{ allUsers: true }	Returns all sessions for all users. 返回所有用户的所有会话。If running with access control, the authenticated user must have privileges with listSession action on the cluster.如果使用访问控制运行，则经过身份验证的用户必须具有在群集上执行listSession操作的权限。

Restrictions限制¶

$listLocalSessions is not allowed in transactions.事务中不允许使用$listLocalSessions。

Examples示例¶

db.aggregate( [  { $listLocalSessions: { allUsers: true } } ] )

db.aggregate( [ { $listLocalSessions: { users: [ { user: "myAppReader", db: "test" } ] } } ] )

db.aggregate( [ { $listLocalSessions: { } } ] )