14.18.1.2 Functions which Configure the Group Replication Mode (original) (raw)

The world's most popular open source database

14.18.1.2 Functions which Configure the Group Replication Mode

The following functions enable you to control the mode which a replication group is running in, either single-primary or multi-primary mode.

• group_replication_switch_to_multi_primary_mode()
  Changes a group running in single-primary mode to multi-primary mode. Must be issued on a member of a replication group running in single-primary mode.
  Syntax:

STRING group_replication_switch_to_multi_primary_mode()  

This function has no parameters.
Return value:
A string containing the result of the operation, for example whether it was successful or not.
Example:

SELECT group_replication_switch_to_multi_primary_mode()  

All members which belong to the group become primaries.
For more information, seeSection 20.5.1.2, “Changing the Group Mode”

• group_replication_switch_to_single_primary_mode()
  Changes a group running in multi-primary mode to single-primary mode, without the need to stop Group Replication. Must be issued on a member of a replication group running in multi-primary mode. When you change to single-primary mode, strict consistency checks are also disabled on all group members, as required in single-primary mode (group_replication_enforce_update_everywhere_checks=OFF).
  Syntax:

STRING group_replication_switch_to_single_primary_mode([str])  

Arguments:

• str: A string containing the UUID of a member of the group which should become the new single primary. Other members of the group become secondaries.
  Return value:
  A string containing the result of the operation, for example whether it was successful or not.
  Example:

SELECT group_replication_switch_to_single_primary_mode(member_uuid);  

For more information, seeSection 20.5.1.2, “Changing the Group Mode”