Deploy a three-replica OceanBase cluster using the CLI|V4.2.0| docs|Distributed Database

Deploy a three-replica OceanBase cluster using the CLI

Last Updated：2025-12-04 02:47:57 Updated

This topic describes how to deploy a three-replica OceanBase cluster using the CLI.

Prerequisites

Before installing OceanBase Database, make sure that the following conditions are met:

The OBServer node has been configured. For more information, see Server configuration, (Optional) Configure a clock source, and Initialize the OBServer node using oat-cli.
You have obtained the RPM package of OceanBase Database. For more information, see Prepare installation packages.

Procedure

Step 1: Install the RPM package

Install the OceanBase Database RPM package.

In this step, $rpm_dir indicates the directory where the RPM package is stored, and $rpm_name indicates the name of the RPM package.

[root@xxx /]# cd $rpm_dir
[root@xxx $rpm_dir]# rpm -ivh $rpm_name

Note

By default, OceanBase Database is installed in the /home/admin/oceanbase directory.

Here is an example:

[root@xxx /home/admin/rpm]# rpm -ivh oceanbase-4.2.0.0-100000052023073123.el7.x86_64.rpm
Preparing...                          ################################# [100%]
Updating / installing...
   1:oceanbase-4.2.0.0-100000052023073################################# [100%]

(Optional) Install OceanBase Client.

OceanBase Client OBClient is a dedicated command-line client tool for OceanBase Database. With OBClient, you can connect to MySQL and Oracle tenants in OceanBase Database. If you only connect to a MySQL tenant, you can also use the MySQL client (mysql) to connect to OceanBase Database.

Notice

Due to the dependency of obclient V2.2.1 and earlier on libobclient, you need to install libobclient first. Contact the technical support team to obtain the OBClient RPM package and the libobclient RPM package.

Here is an example:
```
[root@xxx /home/admin/rpm]# rpm -ivh obclient-2.2.1-20221122151945.el7.alios7.x86_64.rpm
Preparing...                          ################################# [100%]
Updating / installing...
   1:obclient-2.2.1-20221122151945.el7################################# [100%]

##Check whether OceanBase Client is installed##
[root@xxx /home/admin/rpm]# which obclient
/usr/bin/obclient
```

Step 2: Configure directories

Clear the OceanBase directory (if it was cleared during the first deployment).

If you want to clear the previous OceanBase environment or the environment is messy or contains files that will affect the next installation due to an issue that occurred during the OceanBase installation and deployment, you can choose to clear the old OceanBase directory. In this case, you must specify the cluster name $cluster_name.

[root@xxx admin]# su - admin
-bash-4.2$ kill -9 `pidof observer` 
-bash-4.2$ rm -rf /data/1/$cluster_name 
-bash-4.2$ rm -rf /data/log1/$cluster_name 
-bash-4.2$ rm -rf /home/admin/oceanbase/store/$cluster_name /home/admin/oceanbase/log/* /home/admin/oceanbase/etc/*config*
-bash-4.2$ ps -ef|grep observer

Here is an example:

[root@xxx admin]# su - admin
-bash-4.2$ kill -9 `pidof observer` 
-bash-4.2$ rm -rf /data/1/obdemo 
-bash-4.2$ rm -rf /data/log1/obdemo 
-bash-4.2$ rm -rf /home/admin/oceanbase/store/obdemo /home/admin/oceanbase/log/* /home/admin/oceanbase/etc/*config*
-bash-4.2$ ps -ef|grep observer

Initialize the OceanBase directory.

We recommend that you install OceanBase Database's data directory on an independent disk and then link it to the software home directory through a soft link. In this case, you must specify the cluster name $cluster_name.

[root@xxx admin]# su - admin
-bash-4.2$ mkdir -p /data/1/$cluster_name/{etc3,sstable,slog} 
-bash-4.2$ mkdir -p /data/log1/$cluster_name/{clog,etc2} 
-bash-4.2$ mkdir -p /home/admin/oceanbase/store/$cluster_name
-bash-4.2$ for t in {etc3,sstable,slog};do ln -s /data/1/$cluster_name/$t /home/admin/oceanbase/store/$cluster_name/$t; done
-bash-4.2$ for t in {clog,etc2};do ln -s /data/log1/$cluster_name/$t /home/admin/oceanbase/store/$cluster_name/$t; done

Here is an example:

[root@xxx admin]# su - admin
-bash-4.2$ mkdir -p /data/1/obdemo/{etc3,sstable,slog} 
-bash-4.2$ mkdir -p /data/log1/obdemo/{clog,etc2} 
-bash-4.2$ mkdir -p /home/admin/oceanbase/store/obdemo
-bash-4.2$ for t in {etc3,sstable,slog};do ln -s /data/1/obdemo/$t /home/admin/oceanbase/store/obdemo/$t; done
-bash-4.2$ for t in {clog,etc2};do ln -s /data/log1/obdemo/$t /home/admin/oceanbase/store/obdemo/$t; done

Note

The obdemo directory is created based on the cluster name and can be customized. It is used by the startup process.

Check the results:

-bash-4.2$ cd /home/admin/oceanbase
-bash-4.2$ tree store/
store/
`-- obdemo
 |-- clog -> /data/log1/obdemo/clog
 |-- etc2 -> /data/log1/obdemo/etc2
 |-- etc3 -> /data/1/obdemo/etc3
 |-- slog -> /data/1/obdemo/slog
 `-- sstable -> /data/1/obdemo/sstable

6 directories, 0 files

Step 3: Initialize the OceanBase cluster

Note

The example IP address has been desensitized and is not a requirement for installation. You need to specify your own server IP addresses during deployment.

Start the observer process on each node.

Start the observer process on each node as the admin user.

Notice

In a three-replica setup, the startup parameters for each node are different. When you start the observer process, specify the IP addresses of three (or more) servers where RootService resides. You do not need to specify all servers when you create a cluster. After the cluster is created, you can add more servers.

cd /home/admin/oceanbase && /home/admin/oceanbase/bin/observer {-I $ip | -i $devname} -P $rpc_port -p $sql_port -z $zone_name -d /home/admin/oceanbase/store/$cluster_name -r '$ip:2882:2881' -c $cluster_id -n $cluster_name -o "system_memory=30G,datafile_size=500G,config_additional_dir=/data/1/$cluster_name/etc3;/data/log1/$cluster_name/etc2"

The parameters are described as follows:

Parameter	Description
`-I` \| `-i`	`-I`: the IP address of the node to be started. In a multi-server deployment scenario, 127.0.0.1 cannot be specified as the target IP address. We recommend that you use the specified IP address (`-I 10.10.10.1`) to start the node. `-i`: the name of the network interface card. You can view the available network interface card names by using the `ifconfig` command. Note You can specify both the IP address and the network interface card name (`-I 10.10.10.1 -i eth0`) to start the node, but we recommend that you do not specify both parameters.
`-p`	the service port number, which is generally set to `2881`.
`-P`	the RPC port number, which is generally set to `2882`.
`-n`	the cluster name. Custom cluster names must not be repeated.
`-z`	the zone to which the observer process belongs.
`-d`	the directory where the cluster is located. The directory is created when the cluster is initialized. Except for the cluster name `$cluster_name`, other parameters must not be changed.
`-c`	the cluster ID. It is a group of numbers, and custom cluster IDs must not be repeated.
`-l`	the log level.
`-r`	the RootService list in the format of `$ip:2882:2881`; the list is separated by semicolons.
`-o`	the startup parameters (configuration items) of the cluster. Multiple configuration items can be specified, and the values of the configuration items are separated by commas. You can specify appropriate startup parameters and values based on your business requirements to optimize the performance and resource utilization of the cluster. For more information, see the followingcommon cluster startup configuration items.

Here is an example:

zone1:

[root@xxx admin]# su - admin
-bash-4.2$ cd /home/admin/oceanbase && /home/admin/oceanbase/bin/observer -I 10.10.10.1 -P 2882 -p 2881 -z zone1 -d /home/admin/oceanbase/store/obdemo -r '10.10.10.1:2882:2881;10.10.10.2:2882:2881;10.10.10.3:2882:2881' -c 10001 -n obdemo -o "system_memory=30G,datafile_size=500G,config_additional_dir=/data/1/obdemo/etc3;/data/log1/obdemo/etc2"

zone2:

[root@xxx admin]# su - admin
-bash-4.2$ cd /home/admin/oceanbase && /home/admin/oceanbase/bin/observer -I 10.10.10.2 -P 2882 -p 2881 -z zone2 -d /home/admin/oceanbase/store/obdemo -r '10.10.10.1:2882:2881;10.10.10.2:2882:2881;10.10.10.3:2882:2881' -c 10001 -n obdemo -o "system_memory=30G,datafile_size=500G,config_additional_dir=/data/1/obdemo/etc3;/data/log1/obdemo/etc2"

zone3:

[root@xxx admin]# su - admin
-bash-4.2$ cd /home/admin/oceanbase && /home/admin/oceanbase/bin/observer -I 10.10.10.3 -P 2882 -p 2881 -z zone3 -d /home/admin/oceanbase/store/obdemo -r '10.10.10.1:2882:2881;10.10.10.2:2882:2881;10.10.10.3:2882:2881' -c 10001 -n obdemo -o "system_memory=30G,datafile_size=500G,config_additional_dir=/data/1/obdemo/etc3;/data/log1/obdemo/etc2"

You can run the following command to check whether the observer process has been started:

Use the netstat -ntlp command. If the 2881 and 2882 ports are listened to, the process has been started.
Use the ps -ef|grep observer command to return the observer process information.

Here is an example:

-bash-4.2$ netstat -ntlp
(Not all processes could be identified, non-owned process info
will not be shown, you would have to be root to see it all.)
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address           Foreign Address         State       PID/Program name
tcp        0      0 0.0.0.0:2881            0.0.0.0:*               LISTEN      11114/observer
tcp        0      0 0.0.0.0:2882            0.0.0.0:*               LISTEN      11114/observer
...        ...    ...                       ...                     ...         ...

-bash-4.2$ ps -ef|grep observer
admin     11114      0 40 16:18 ?        00:00:17 /home/admin/oceanbase/bin/observer -I 10.10.10.1 -P 2882 -p 2881 -z zone1 -d /home/admin/oceanbase/store/obdemo -r 10.10.10.1:2882:2881;10.10.10.2:2882:2881;10.10.10.3:2882:2881 -c 10001 -n obdemo -o system_memory=30G,datafile_size=500G,config_additional_dir=/data/1/obdemo/etc3;/data/log1/obdemo/etc2

Perform the bootstrap operation to initialize the cluster.

Use OBClient to connect to any server. The password is empty.
```
[root@xxx admin]# obclient -h127.0.0.1 -uroot -P2881 -p******

obclient> SET SESSION ob_query_timeout=1000000000;
Query OK, 0 rows affected

obclient> ALTER SYSTEM BOOTSTRAP ZONE 'zone1' SERVER '10.10.10.1:2882',ZONE 'zone2' SERVER '10.10.10.2:2882',ZONE 'zone3' SERVER '10.10.10.3:2882';
Query OK, 0 rows affected
```
Notice

If an error occurs during this step, check whether the startup parameters of the observer process are correctly specified, whether the directory where the observer process resides has the correct permissions, whether the log directory has sufficient space (if it is the same directory as the data directory, check whether the data directory has sufficient space), whether the node time is synchronized, and whether the node has sufficient memory resources. If the problem persists, clear the OceanBase directory and deploy the software again.
Verify whether the cluster has been initialized.

After the bootstrap initialization is completed, execute the SHOW DATABASES; command to verify whether the initialization is successful. If the query result shows a database named oceanbase in the database list, the initialization is successful.
Change the password.

By default, the root user of the sys tenant has an empty password. We recommend that you change the password after the initialization is successful.
```
ALTER USER root IDENTIFIED BY '******';
```

Next steps

After the cluster is created, you can create user tenants as needed.

For more information about how to create a user tenant using the CLI, see Create a tenant.

Deploy a three-replica OceanBase cluster using the CLI

Prerequisites

Procedure

Step 1: Install the RPM package

Note

Notice

Step 2: Configure directories

Note

Step 3: Initialize the OceanBase cluster

Note

Notice

Note

Notice

Next steps

References