Guide to Expanding an OceanBase Cluster: Adding Zones and Resources

1. Environment Description

Cluster expansion can be done by expanding replicas (zones) or resources (OBServers). The original deployment mode is 1‑1‑1.

2. White‑screen Expansion

To expand replicas: OCP → target cluster → Overview → Add zone.

To expand resources: OCP → target cluster → Overview → Add OBServer.

3. Black‑screen Expansion

3.1 Expand Replicas (Zone)

Automated expansion using OBD:

vi /data/5zones.yaml
# Only need to configure when remote login is required
user:
    username: admin
    #password: admin
    key_file: /home/admin/.ssh/id_rsa.pub
    #port: your ssh port, default 22
    # timeout: ssh connection timeout (second), default 30
oceanbase-ce:
    servers:
        # Please don use hostname, only IP can be supported
        - name: observer4
          ip: 10.186.60.175
        - name: observer5
          ip: 10.186.60.176

    global:
        ......
        appname: ywob2
        ......

    observer4:
        mysql_port: 2881 # External port for OceanBase Database. The default value is 2881.
        rpc_port: 2882 # Internal port for OceanBase Database. The default value is 2882.
        home_path: /home/admin/oceanbase-ce
        data_dir: /data
        redo_dir: /redo
        zone: zone4
    observer5:
        mysql_port: 2881
        rpc_port: 2882
        home_path: /home/admin/oceanbase-ce
        data_dir: /data
        redo_dir: /redo
        zone: zone5

Deploy the cluster:

obd cluster deploy ywob2 -c 5zones.yaml

Merge configuration, start the original cluster, and add new zones:

obd cluster start ywob
+------------------------------------------------+
|                    observer                    |
+--------------+---------+------+-------+--------+
|ip            | version | port | zone  | status |
+--------------+---------+------+-------+--------+
|10.186.60.85  | 3.2.2   | 2881 | zone1 | active |
|10.186.60.173 | 3.2.2   | 2881 | zone2 | active |
|10.186.60.174 | 3.2.2   | 2881 | zone3 | active |
+------------------------------------------------+

Check processes, add new nodes, and verify:

mysql> alter system add zone 'zone4' region 'sys_region';
mysql> alter system add zone 'zone5' region 'sys_region';
mysql> alter system start zone 'zone4';
mysql> alter system start zone 'zone5';
mysql> alter system add server '10.186.60.175:2882' zone 'zone4';
mysql> alter system add server '10.186.60.176:2882' zone 'zone5';
mysql> alter system start server '10.186.60.175:2882' zone 'zone4';
mysql> alter system start server '10.186.60.176:2882' zone 'zone5';
obd cluster display ywob
+------------------------------------------------+
|                    observer                    |
+--------------+---------+------+-------+--------+
|ip            | version | port | zone  | status |
+--------------+---------+------+-------+--------+
|10.186.60.85  | 3.2.2   | 2881 | zone1 | active |
|10.186.60.173 | 3.2.2   | 2881 | zone2 | active |
|10.186.60.174 | 3.2.2   | 2881 | zone3 | active |
|10.186.60.175 | 3.2.2   | 2881 | zone4 | active |
|10.186.60.176 | 3.2.2   | 2881 | zone5 | active |
+------------------------------------------------+

For tenant data‑replica expansion, follow the same steps; to shrink, remove nodes and adjust locality.

3.2 Expand Resources (OBServer)

Install and start observer processes on new hosts (example for 10.186.60.175, .176, .177):

su - admin
sudo rpm -ivh /tmp/oceanbase-ce-*.rpm

cd ~/oceanbase && bin/observer -i eth0 -p 2881 -P 2882 -z zone1 \
-d ~/oceanbase/store/ywob \
-r '10.186.65.85:2882:2881;10.186.60.173:2882:2881;10.186.60.174:2882:2881;10.186.60.175:2882:2881;10.186.60.176:2882:2881;10.186.60.177:2882:2881' \
-c 20230131 -n ywob \
-o "memory_limit=8G,cache_wash_threshold=1G,__min_full_resource_pool_memory=268435456,system_memory=3G,memory_chunk_cache_size=128M,cpu_count=12,net_thread_count=4,datafile_size=50G,stack_size=1536K,config_additional_dir=/data/ywob/etc3;/redo/ywob/etc2"
... (similar commands for other zones)

Verify processes and ports, add new servers to zones, and check cluster status with SQL queries such as:

select zone,svr_port,inner_port,with_rootserver,status from __all_server order by zone, svr_ip;

3.3 Shrink Resources (OBServer)

Reduce the cluster from a 2‑2‑2 to a 1‑1‑1 configuration by decreasing unit numbers and deleting observers:

alter resource pool pool_yw1 unit_num = 1;
alter system delete server '10.186.60.175:2882' zone zone3;
alter system delete server '10.186.60.176:2882' zone zone2;
alter system delete server '10.186.60.177:2882' zone zone1;

Check the final node list and tenant partition distribution to confirm data re‑balancing.