(mysql.info) mysql-cluster-single-user-mode

Info Catalog

(mysql.info) mysql-cluster-event-reports

(mysql.info) mysql-cluster-management

(mysql.info) mysql-cluster-backup

 
 15.6.4 Single-User Mode
 -----------------------
 
 Single-user mode allows the database administrator to restrict access
 to the database system to a single MySQL server (SQL node). When
 entering single-user mode, all connections to all other MySQL servers
 are closed gracefully and all running transactions are aborted. No new
 transactions are allowed to be started.
 
 Once the cluster has entered single-user mode, only the designated SQL
 node is granted access to the database.
 
 You can use the `ALL STATUS' command to see when the cluster has
 entered single-user mode.
 
 Example:
 
      NDB> ENTER SINGLE USER MODE 5
 
 After this command has executed and the cluster has entered single-user
 mode, the SQL node whose node ID is `5' becomes the cluster's only
 permitted user.
 
 The node specified in the preceding command must be a MySQL Server
 node; An attempt to specify any other type of node will be rejected.
 
 * When the preceding commmand is invoked, all transactions
 running on the designated node are aborted, the connection is closed,
 and the server must be restarted.
 
 The command `EXIT SINGLE USER MODE' changes the state of the cluster's
 data nodes from single-user mode to normal mode. MySQL Servers waiting
 for a connection (that is, for the cluster to become ready and
 available), are again permitted to connect. The MySQL Server denoted as
 the single-user SQL node continues to run (if still connected) during
 and after the state change.
 
 Example:
 
      NDB> EXIT SINGLE USER MODE
 
 There are two recommended ways to handle a node failure when running in
 single-user mode:
 
    * Method 1:
 
        1. Finish all single-user mode transactions
 
        2. Issue the `EXIT SINGLE USER MODE' command
 
        3. Restart the cluster's data nodes
 
    * Method 2:
 
      Restart database nodes prior to entering single-user mode.
 

Info Catalog

(mysql.info) mysql-cluster-event-reports

(mysql.info) mysql-cluster-management

(mysql.info) mysql-cluster-backup