CANCEL SESSION

The CANCEL SESSION statement lets you stop long-running sessions. CANCEL SESSION will attempt to cancel the currently active query and end the session.

Required privileges

Only members of the admin role and the user that the session belongs to can cancel a session. By default, the root user belongs to the admin role.

Synopsis

CANCELSESSIONIFEXISTSsession_idSESSIONSIFEXISTSselect_stmt

Parameters

ParameterDescription
session_idThe ID of the session you want to cancel, which can be found with SHOW SESSIONS.CANCEL SESSION accepts a single session ID. If a subquery is used and returns multiple IDs, the CANCEL SESSION statement will fail. To cancel multiple sessions, use CANCEL SESSIONS.
select_stmtA selection query that returns session_id(s) to cancel.

Example

Cancel a single session

In this example, we use the SHOW SESSIONS statement to get the ID of a session and then pass the ID into the CANCEL SESSION statement:

  1. > SHOW SESSIONS;
  1. +---------+----------------------------------+-----------+...
  2. | node_id |            session_id            | user_name |...
  3. +---------+----------------------------------+-----------+...
  4. |       1 | 1530c309b1d8d5f00000000000000001 | root      |...
  5. +---------+----------------------------------+-----------+...
  6. |       1 | 1530fe0e46d2692e0000000000000001 | maxroach  |...
  7. +---------+----------------------------------+-----------+...
  1. > CANCEL SESSION '1530fe0e46d2692e0000000000000001';

You can also cancel a session using a subquery that returns a single session ID:

  1. > CANCEL SESSIONS (SELECT session_id FROM [SHOW SESSIONS]
  2.       WHERE username = 'root');

Cancel multiple sessions

Use the SHOW SESSIONS statement to view all active sessions:

  1. > SHOW SESSIONS;
  1. +---------+----------------------------------+-----------+...
  2. | node_id |            session_id            | user_name |...
  3. +---------+----------------------------------+-----------+...
  4. |       1 | 1530c309b1d8d5f00000000000000001 | root      |...
  5. +---------+----------------------------------+-----------+...
  6. |       1 | 1530fe0e46d2692e0000000000000001 | maxroach  |...
  7. +---------+----------------------------------+-----------+...
  8. |       1 | 15310cc79671fc6a0000000000000001 | maxroach  |...
  9. +---------+----------------------------------+-----------+...

To cancel multiple sessions, nest a SELECT clause that retrieves session_id(s) inside the CANCEL SESSIONS statement:

  1. > CANCEL SESSIONS (SELECT session_id FROM [SHOW SESSIONS]
  2.       WHERE user_name = 'maxroach');

All sessions created by maxroach will be cancelled.

See also

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