# Managing active-active clusters


The following stored procedures set up and manage RDS for MySQL active-active clusters. For more information, see [Configuring active-active clusters for RDS for MySQL](mysql-active-active-clusters.md).

These stored procedures are only available with RDS for MySQL DB instances running the following versions:
+ All MySQL 8.4 versions
+ MySQL 8.0.35 and higher minor versions

**Topics**
+ [

## mysql.rds\$1group\$1replication\$1advance\$1gtid
](#mysql_rds_group_replication_advance_gtid)
+ [

## mysql.rds\$1group\$1replication\$1create\$1user
](#mysql_rds_group_replication_create_user)
+ [

## mysql.rds\$1group\$1replication\$1set\$1recovery\$1channel
](#mysql_rds_group_replication_set_recovery_channel)
+ [

## mysql.rds\$1group\$1replication\$1start
](#mysql_rds_group_replication_start)
+ [

## mysql.rds\$1group\$1replication\$1stop
](#mysql_rds_group_replication_stop)

## mysql.rds\$1group\$1replication\$1advance\$1gtid


Creates placeholder GTIDs on the current DB instance.

### Syntax


```
CALL mysql.rds_group_replication_advance_gtid(
begin_id
, end_id
, server_uuid
);
```

### Parameters


 *begin\$1id*   
The start transaction ID to be created.

 *end\$1id*   
The end transaction ID to be created.

 *begin\$1id*   
The `group_replication_group_name` for the transaction to be created. The `group_replication_group_name` is specified as a UUID in the DB parameter group associated with the DB instance.

### Usage notes


In an active-active cluster, for a DB instance to join a group, all GTID transactions executed on the new DB instance must exist on the other members in the cluster. In unusual cases, a new DB instance might have more transactions when transactions are executed before joining the instance to group. In this case, you can't remove any existing transactions, but you can use this procedure to create the corresponding placeholder GTIDs on the othe DB instances in the group. Before doing so, verify that the transactions *don't affect the replicated data*.

When you call this procedure, GTID transactions of `server_uuid:begin_id-end_id` are created with empty content. To avoid replication issues, don't use this procedure under any other conditions.

**Important**  
Avoid calling this procedure when the active-active cluster is functioning normally. Don't call this procedure unless you understand the possible consequences of the transactions you are creating. Calling this procedure might result in inconsistent data.

### Example


The following example creates placeholder GTIDs on current DB instance.:

```
CALL mysql.rds_group_replication_advance_gtid(5, 6, '11111111-2222-3333-4444-555555555555');
```

## mysql.rds\$1group\$1replication\$1create\$1user


Creates the replication user `rdsgrprepladmin` for group replication on the DB instance.

### Syntax


```
CALL mysql.rds_group_replication_create_user(
replication_user_password
);
```

### Parameters


 *replication\$1user\$1password*   
The password of the replication user `rdsgrprepladmin`.

### Usage notes

+ The password of the replication user `rdsgrprepladmin` must be the same on all of the DB instances in an active-active cluster.
+ The `rdsgrprepladmin` user name is reserved for group replication connections. No other user, including the master user, can have this user name.

### Example


The following example creates the replication user `rdsgrprepladmin` for group replication on the DB instance:

```
CALL mysql.rds_group_replication_create_user('password');
```

## mysql.rds\$1group\$1replication\$1set\$1recovery\$1channel


Sets the `group_replication_recovery` channel for an active-active cluster. The procedure uses the reserved `rdsgrprepladmin` user to configure the channel.

### Syntax


```
CALL mysql.rds_group_replication_set_recovery_channel(
replication_user_password);
```

### Parameters


 *replication\$1user\$1password*   
The password of the replication user `rdsgrprepladmin`.

### Usage notes


The password of the replication user `rdsgrprepladmin` must be the same on all of the DB instances in an active-active cluster. A call to the `mysql.rds_group_replication_create_user` specifies the password.

### Example


The following example sets the `group_replication_recovery` channel for an active-active cluster:

```
CALL mysql.rds_group_replication_set_recovery_channel('password');
```

## mysql.rds\$1group\$1replication\$1start


Starts group replication on the current DB instance.

### Syntax


```
CALL mysql.rds_group_replication_start(
bootstrap
);
```

### Parameters


 *bootstrap*   
A value that specifies whether to initialize a new group or join an existing group. `1` initializes a new group with the current DB instance. `0` joins the current DB instance to an existing group by connecting to the endpoints defined in `group_replication_group_seeds` parameter in the of DB parameter group associated with the DB instance.

### Example


The following example initializes a new group with the current DB instance:

```
CALL mysql.rds_group_replication_start(1);
```

## mysql.rds\$1group\$1replication\$1stop


Stops group replication on the current DB instance.

### Syntax


```
CALL mysql.rds_group_replication_stop();
```

### Usage notes


When you stop replication on a DB instance, it doesn't affect any other DB instance in the active-active cluster.