wait_timeout

Description

wait_timeout sets the number of seconds that the server waits for activity before closing a noninteractive connection.

Privilege requirements

• Query variables

  • Global level

    You can use the SHOW VARIABLES statement or query the SYS.TENANT_VIRTUAL_GLOBAL_VARIABLE view (Oracle mode) or information_schema.GLOBAL_VARIABLES view (MySQL mode) to view the values of global system variables for the sys tenant and user tenants.

  • Session level

    In both Oracle and MySQL compatible modes, the sys tenant and all user tenants can query session system variables by using the SHOW VARIABLES statement or views. In Oracle compatible mode, session system variables are displayed in the SYS.TENANT_VIRTUAL_SESSION_VARIABLE view. In MySQL compatible mode, session system variables are displayed in the information_schema.SESSION_VARIABLES view.

• Modify variables

  • Global level

    • You can directly modify the values of Global system variables in the sys tenant.

    • MySQL user tenants must have the SUPER or ALTER SYSTEM permission to modify Global system variable values.

    • For V4.x, from V4.2.0 onward, Oracle user tenants need the ALTER SYSTEM privilege to modify the values of Global system variables.

  • Session level

    All tenants, including the sys tenant, can directly modify the values of session system variables for their tenants.

Attributes

Description

At the start of the session, the system initializes the value of the wait_timeout session variable based on the value of the global wait_timeout or interactive_timeout variable, depending on the client type. The CLIENT_INTERACTIVE connection option in mysql_real_connect() defines the client type. For more information about the interactive_timeout variable, see interactive_timeout.

Examples

Set the time that the server waits for active connections before closing them to 1800 seconds or 30 minutes.

• Session level

  obclient> SET wait_timeout =1800;
  

• Global level

  obclient> SET GLOBAL wait_timeout =1800;
  

References

If you want to set the number of seconds that the server waits for an interactive connection to become inactive before closing it, see interactive_timeout.