Remove Instance from InnoDb cluster in MYSQL

 [root@nikash-db2 ~]# cat /etc/hosts
127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6
15.68.13.86        nikash-db1
15.68.13.87        nikash-db2
15.68.13.88        nikash-db3
15.68.13.89     nikash-db4
[root@nikash-db2 ~]#

mysql> select member_host,member_role from performance_schema.replication_group_members;
+-------------+-------------+
| member_host | member_role |
+-------------+-------------+
| nikash-db2  | SECONDARY   |
| nikash-db4  | PRIMARY     |
| nikash-db3  | SECONDARY   |
+-------------+-------------+
3 rows in set (0.00 sec)

mysql>

[root@nikash-db2 ~]# mysql --user root --password=Bankasia#2020 --host 10.88.13.87 --port 4407 nikash_np_eft
mysql: [Warning] Using a password on the command line interface can be insecure.
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 112997
Server version: 8.0.31-cluster MySQL Cluster Community Server - GPL

Copyright (c) 2000, 2022, Oracle and/or its affiliates.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> select @@hostname;
+------------+
| @@hostname |
+------------+
| nikash-db2 |
+------------+
1 row in set (0.01 sec)



[root@nikash-db2 ~]# mysqlsh
MySQL Shell 8.0.31

Copyright (c) 2016, 2022, Oracle and/or its affiliates.
Oracle is a registered trademark of Oracle Corporation and/or its affiliates.
Other names may be trademarks of their respective owners.

Type '\help' or '\?' for help; '\quit' to exit.
 MySQL  JS > root@nikash-db2
SyntaxError: Invalid or unexpected token
 MySQL  JS > \c root@nikash-db2
Creating a session to 'root@nikash-db2'
Fetching schema names for auto-completion... Press ^C to stop.
Your MySQL connection id is 111803 (X protocol)
Server version: 8.0.31-cluster MySQL Cluster Community Server - GPL
No default schema selected; type \use <schema> to set one.
 MySQL  nikash-db2:33060+ ssl  JS > c.status()
ReferenceError: c is not defined
 MySQL  nikash-db2:33060+ ssl  JS > var c=dba.getCluster()
 MySQL  nikash-db2:33060+ ssl  JS > c.status()
{
    "clusterName": "nikash_db_cluster",
    "defaultReplicaSet": {
        "name": "default",
        "primary": "nikash-db4:4407",
        "ssl": "REQUIRED",
        "status": "OK",
        "statusText": "Cluster is ONLINE and can tolerate up to ONE failure.",
        "topology": {
            "nikash-db2:4407": {
                "address": "nikash-db2:4407",
                "instanceErrors": [
                    "WARNING: Instance is NOT a PRIMARY but super_read_only option is OFF."
                ],
                "memberRole": "SECONDARY",
                "mode": "R/W",
                "readReplicas": {},
                "replicationLag": "applier_queue_applied",
                "role": "HA",
                "status": "ONLINE",
                "version": "8.0.31"
            },
            "nikash-db3:4407": {
                "address": "nikash-db3:4407",
                "memberRole": "SECONDARY",
                "mode": "R/O",
                "readReplicas": {},
                "replicationLag": "applier_queue_applied",
                "role": "HA",
                "status": "ONLINE",
                "version": "8.0.31"
            },
            "nikash-db4:4407": {
                "address": "nikash-db4:4407",
                "memberRole": "PRIMARY",
                "mode": "R/W",
                "readReplicas": {},
                "replicationLag": "applier_queue_applied",
                "role": "HA",
                "status": "ONLINE",
                "version": "8.0.31"
            }
        },
        "topologyMode": "Single-Primary"
    },
    "groupInformationSourceMember": "nikash-db4:4407"
}
 MySQL  nikash-db2:33060+ ssl  JS >
 
 
  MySQL  nikash-db2:33060+ ssl  JS > c.describe()
{
    "clusterName": "nikash_db_cluster",
    "defaultReplicaSet": {
        "name": "default",
        "topology": [
            {
                "address": "nikash-db2:4407",
                "label": "nikash-db2:4407",
                "role": "HA"
            },
            {
                "address": "nikash-db3:4407",
                "label": "nikash-db3:4407",
                "role": "HA"
            },
            {
                "address": "nikash-db4:4407",
                "label": "nikash-db4:4407",
                "role": "HA"
            }
        ],
        "topologyMode": "Single-Primary"
    }
}
 MySQL  nikash-db2:33060+ ssl  JS >
 
 
 
  MySQL  nikash-db2:33060+ ssl  JS > c.listRouters();
{
    "clusterName": "nikash_db_cluster",
    "routers": {
        "nikash-db2::system": {
            "hostname": "nikash-db2",
            "lastCheckIn": "2024-10-09 14:25:48",
            "roPort": "6447",
            "roXPort": "6449",
            "rwPort": "6446",
            "rwXPort": "6448",
            "version": "8.0.31"
        }
    }
}
 MySQL  nikash-db2:33060+ ssl  JS >
 
----------------------Remove INSTANCE from InnoDB cluster------------------

 
MySQL  nikash-db2:33060+ ssl  JS > c.removeInstance('nikash-db4:4407')
The instance will be removed from the InnoDB cluster. Depending on the instance
being the Seed or not, the Metadata session might become invalid. If so, please
start a new session to the Metadata Storage R/W instance.

* Waiting for instance 'nikash-db4:4407' to synchronize with the primary...
** Transactions replicated  ############################################################  100%

* Instance 'nikash-db4:4407' is attempting to leave the cluster...

The instance 'nikash-db4:4407' was successfully removed from the cluster.

 MySQL  nikash-db2:33060+ ssl  JS >
 
 
 --------------------Now check Cluster Group Member-------------
 
 mysql> select member_host,member_role from performance_schema.replication_group_members;
+-------------+-------------+
| member_host | member_role |
+-------------+-------------+
| nikash-db2  | PRIMARY     |
| nikash-db3  | SECONDARY   |
+-------------+-------------+
2 rows in set (0.00 sec)

mysql>



MySQL  nikash-db2:33060+ ssl  JS > c.removeInstance('nikash-db3:4407')
The instance will be removed from the InnoDB cluster. Depending on the instance
being the Seed or not, the Metadata session might become invalid. If so, please
start a new session to the Metadata Storage R/W instance.

* Waiting for instance 'nikash-db3:4407' to synchronize with the primary...
** Transactions replicated  ############################################################  100%

* Instance 'nikash-db3:4407' is attempting to leave the cluster...

The instance 'nikash-db3:4407' was successfully removed from the cluster.

 MySQL  nikash-db2:33060+ ssl  JS >


mysql> select member_host,member_role from performance_schema.replication_group_members;
+-------------+-------------+
| member_host | member_role |
+-------------+-------------+
| nikash-db2  | PRIMARY     |
+-------------+-------------+
1 row in set (0.00 sec)

mysql>



 MySQL  nikash-db2:33060+ ssl  JS > c.status()
{
    "clusterName": "nikash_db_cluster",
    "defaultReplicaSet": {
        "name": "default",
        "primary": "nikash-db2:4407",
        "ssl": "REQUIRED",
        "status": "OK_NO_TOLERANCE",
        "statusText": "Cluster is NOT tolerant to any failures.",
        "topology": {
            "nikash-db2:4407": {
                "address": "nikash-db2:4407",
                "memberRole": "PRIMARY",
                "mode": "R/W",
                "readReplicas": {},
                "replicationLag": "applier_queue_applied",
                "role": "HA",
                "status": "ONLINE",
                "version": "8.0.31"
            }
        },
        "topologyMode": "Single-Primary"
    },
    "groupInformationSourceMember": "nikash-db2:4407"
}
 MySQL  nikash-db2:33060+ ssl  JS >
 
 
 MySQL  nikash-db2:33060+ ssl  JS > c.describe()
{
    "clusterName": "nikash_db_cluster",
    "defaultReplicaSet": {
        "name": "default",
        "topology": [
            {
                "address": "nikash-db2:4407",
                "label": "nikash-db2:4407",
                "role": "HA"
            }
        ],
        "topologyMode": "Single-Primary"
    }
}
 MySQL  nikash-db2:33060+ ssl  JS >