Deploy OceanBase Database by using systemd

This topic describes how to deploy and manage OceanBase Database on a single server by using systemd.

Prerequisites

Before you start, make sure that the following conditions are met:

• You are using one of the following RPM-based operating systems:

  • CentOS Linux 7.X and 8.X

  • Anolis OS 8.X and 23

  • openSUSE 15.X

  • openEuler 22.03

• You have installed jq, a command-line tool, in your environment and configured systemd as the system and service manager.

• You have installed the mysql client or OceanBase Client (OBClient) in your environment for database connection.

• You are going to deploy OceanBase Database V4.2.2 or later.

• You have the permissions to run sudo commands.

Deploy OceanBase Database

Step 1: Install OceanBase Database

You can install OceanBase Database online or offline, depending on whether your environment is connected to the Internet.

Step 2: Start OceanBase Database

You can start OceanBase Database by performing the following steps:

1. (Optional) Modify the configuration file.

   Run the following command to open the configuration file and modify it by referring to this step. If you skip this step, default configurations are used.

   [admin@test001 ~]$ vim /etc/oceanbase.cnf
   

   The configuration file contains the following parameters:

   mysqlPort=2881
   rootPwd=""
   redoDir=/var/lib/oceanbase/redo
   dataDir=/var/lib/oceanbase/data
   datafile_size=2G
   cpu_count=16
   memory_limit=6G
   system_memory=1G
   log_disk_size=13G
   

   Note

   • You can add other parameters to the configuration file. For more information about the parameters, see Parameter summary.

   • By default, the IP address of the OBServer node is 127.0.0.1 and the zone is zone1. You cannot modify the two parameters.

   The following table describes parameters in the configuration file.

   Parameter	Required?	Default value	Description
   mysqlPort	No	2881	The port number for the SQL service protocol of OceanBase Database.
   rootPwd	No	Empty	The password of the super administrator (root@sys) of the OceanBase cluster. We recommend that you set a complex password.
   redoDir	No	/var/lib/oceanbase/redo	The directory for storing clogs, ilogs, and slogs. We recommend that you set the directory on a separate disk.
   dataDir	No	/var/lib/oceanbase/data	The directory for storing SSTables and other data. We recommend that you set the directory on a separate disk.
   datafile_size	No	0	The size of the data file block_file on the corresponding OBServer node. If this parameter is not configured, the datafile_disk_percentage parameter takes effect. For more information, see datafile_size and datafile_disk_percentage.
   cpu_count	No	0	The total number of CPU cores that OceanBase Database can use. If you set the parameter to 0, the system will automatically detect the number of CPU cores.
   memory_limit	No	0	The maximum memory that the observer process can obtain from the environment. If this parameter is not configured, the memory_limit_percentage parameter takes effect. For more information about the two parameters, see memory_limit and memory_limit_percentage.
   system_memory	No	0M	The reserved system memory, which is part of memory_limit. If this parameter is not configured, OceanBase Database reserves memory for the system in adaptive mode.
   log_disk_size	No	0	The size of the redo log disk. If this parameter is not configured, the log_disk_percentage parameter takes effect. For more information, see log_disk_size and log_disk_percentage.

2. Start OceanBase Database.

   [admin@test001 ~]$ sudo systemctl start oceanbase
   

Step 3: Connect to OceanBase Database

In this example, OBClient is used to connect to OceanBase Database. Run the following command:

[admin@test001 ~]$ obclient -h127.0.0.1 -uroot@sys -P2881 -p -A oceanbase

where

• -h specifies the IP address for connecting to OceanBase Database. If you start OceanBase Database by using systemd, the IP address is 127.0.0.1 by default.

• -u specifies the OceanBase Database account in the username@tenant name format. The default username of the administrator of a MySQL tenant is root.

• -P specifies the port for connecting to OceanBase Database. If you start OceanBase Database by using systemd, the port number is 2881 by default.

• -p specifies the password of the tenant account for connecting to OceanBase Database. Instead of providing the password in the command, we recommend that you enter the password as prompted after you run the command. This way, the password is masked.

• -A specifies not to automatically retrieve the statistical information when connecting to OceanBase Database.

• oceanbase specifies the name of the database to access. You can change it to the name of a business database.

Manage OceanBase Database

Currently, you can use systemd only to start, stop, and view the status of OceanBase Database.

• View the status of OceanBase Database

  [admin@test001 ~]$ sudo systemctl status oceanbase
  

  OceanBase Database may be in one of the following states:

  • If the value of the Active field is active (running), and that of the Status field is Service is running, OceanBase Database is being started.

  • If the value of the Active field is active (running), and that of the Status field is Service is ready, OceanBase Database is successfully started.

  • If the value of the Active field is inactive (dead), OceanBase Database is stopped.

  • If the value of the Active field is failed, an error occurred to OceanBase Database and you must check the logs for troubleshooting.

• Stop OceanBase Database

  [admin@test001 ~]$ sudo systemctl stop oceanbase
  

• Uninstall OceanBase Database

  We recommend that you stop OceanBase Database first, and then perform the following steps to uninstall it:

  1. Delete the package of OceanBase Database.

     If you have installed OceanBase Database online, run the following command to delete the package:

     [admin@test001 ~]$ sudo yum erase package 
     

     You must replace package with the actual name of the package to be deleted. To view the package name, run the yum list | grep oceanbase command.

     If you have installed OceanBase Database offline, run the following command to delete the package:

     [admin@test001 ~]$ sudo rpm -e package
     

     You must replace package with the actual name of the package to be deleted. To view the package name, run the rpm -qa | grep oceanbase command.

  2. (Optional) Delete the data of OceanBase Database.

     After you perform the preceding step, OceanBase Database is uninstalled from your environment, but the database data still exists. If you redeploy OceanBase Database later, you can view and use the data.

     After you perform this step, the data of OceanBase Database is completely deleted.

     Delete the installation directory of OceanBase Database.

     [admin@test001 ~]$ rm -rf /home/admin/oceanbase 
     

     Delete the data directory of OceanBase Database.

     [admin@test001 ~]$ rm -rf /var/lib/oceanbase 
     

References

• You can log on to the cluster and run the ALTER USER command to modify the user password. For more information, see ALTER USER.

• For more information about how to connect to OceanBase Database after the deployment, see Connect to OceanBase Database.