This topic describes how to create an arbitration service.
Applicability
This topic applies only to OceanBase Cloud Platform Enterprise Edition. OceanBase Cloud Platform Community Edition does not support the arbitration service.
Prerequisites
The host for deploying an arbitration service has not been deployed with any OceanBase Database cluster.
Procedure
Log on to the OceanBase Cloud Platform (OCP) console.
In the left-side navigation pane, click Clusters.
In the upper-right corner of the Cluster Overview page, click the More icon, and choose Arbitration Service Management.
On the Arbitration Service List page, click Create Arbitration Service.
In the Create Arbitration Service panel, configure the basic information of the arbitration service.
Parameter Description Host The host for deploying the arbitration service. You can deploy multiple arbitration service processes on the same host. You can search for hosts by IP address or click Add Host in the drop-down list to add an available host. Service Version The OceanBase Database version of the cluster. The hardware architecture of the selected version must be the same as that of the host. Only software packages of OceanBase Database V4.1 or later are supported. You can also click Add Version at the bottom of the drop-down list to upload a software package of the required version. OS User The OS user that you use to install and run OceanBase Database. You cannot edit this parameter here. You can change the default value of the ocp.operation.default.os.userparameter to set this user. For more information, see Modify system parameters.Note
The modification of theocp.operation.default.os.userparameter affects only the following operations: create a distributed cluster, create an OBProxy cluster, and create arbitration service. Other settings of existing clusters are not affected.Software Path The path where the arbitration service software is installed. You must have the write permission on the path on the host. - If the OS user is admin, the default software installation path is
/home/admin/oceanbase. You can change the path. - If the OS user is not admin, the default software installation path is
/opt/oceanbase/oceanbase. You can change the path.
Service Port The port of the arbitration service. By default, Port 2882 is used. You can use a custom port based on your business requirements. Make sure that the port is not occupied. Description The supplementary description of the arbitration service. This parameter is optional. Parameter Configurations The startup parameters of the arbitration service. For more information, see Startup parameters. - If the OS user is admin, the default software installation path is
Click OK. In the window that appears, click the task ID to view the task execution status.
The system verifies the parameter settings. If the settings fail the verification, you can perform troubleshooting or modify the parameters as prompted.
Startup parameters
The following table describes the startup parameters of the arbitration service of OCP. For more information about the parameters, see OceanBase Database parameters.
| Parameter | Description | Remarks |
|---|---|---|
| cpu_count | The number of CPU cores. | If you want to deploy only an arbitration service, you do not need to specify this parameter. The arbitration service automatically obtains the number of CPU cores of the host where the database resides. The number of CPU cores affects the number of threads in the thread pool of the arbitration service. |
| enable_syslog_recycle | Specifies whether to enable automatic log file recycling. Default value: False. |
If you set this parameter to True, you can set the max_syslog_file_count parameter to specify the number of log files to retain.
NoticeWe recommend that you set the |
| log_disk_percentage | The percentage of the disk space available for redo logs. Default value: 0. | Evaluation rules: |
| log_disk_size | The size of the log disk where redo logs are stored. Default value: 0. | If you set this parameter to 0, the log disk space is allocated based on the value of log_disk_percentage. |
| max_syslog_file_count | The maximum number of log files that can be retained. Default value: 0. | - |
| memory_limit | The maximum size of memory that the observer process can use. The default value is calculated by using the following formula: Physical memory of the host × memory_limit_percentage. |
In OceanBase Database V4.1.0 BP1 and later, if an OBServer node starts in arbitration service mode, the minimum memory size is 1 GB. However, if the OBServer node starts in other modes, the minimum memory size is 4 GB for the sake of stability. |
| syslog_io_bandwidth_limit | The maximum bandwidth available for log printing per second. If this value is reached, the remaining system logs will be discarded. The default bandwidth is 30 MB. | You can adjust the value as needed. |
| syslog_level | The level of system logs. Default value: WDIAG. |
We recommend that you use the default value. |
| system_memory | The size of memory reserved by the system for the sys500 tenant. The default memory size is 0 MB. |
We recommend that you use the default value. |
| __easy_memory_limit | The maximum size of memory for sending RPC packets to a single OBServer node. The default memory size is 4 GB. | In OceanBase Database V4.1.0 BP1 and later, the minimum memory size is 256 MB. |