## 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, see Section 18.5.1.2, “Changing a Group’s 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, see Section 18.5.1.2, “Changing a Group’s Mode” 

## 13.4.3.5 Functions to Inspect and Configure the Maximum Consensus Instances of a Group 

The following functions enable you to inspect and configure the maximum number of consensus instances that a group can execute in parallel. 

• group_replication_get_write_concurrency() 

Check the maximum number of consensus instances that a group can execute in parallel. 

## Syntax: 

INT group_replication_get_write_concurrency() 

This function has no parameters. 

## Return value: 

The maximum number of consensus instances currently set for the group. 

## Example: 

SELECT group_replication_get_write_concurrency() 

For more information, see Section 18.5.1.3, “Using Group Replication Group Write Consensus” . 

• group_replication_set_write_concurrency() 

