Replace an OBServer node

You can install an OBServer node on a new host to replace the current OBServer node. This topic describes how to replace a faulty or low-performance OBServer node with an OBServer node that is healthy or provides higher performance.

Prerequisites

• Make sure that you have the following permissions:

  • Resource Permissions: Cluster Maintenance permission
  • Menu Permissions: Permission on the Overview menu of Clusters

• The target OceanBase cluster is managed in the current OceanBase Cloud Platform (OCP) cluster.

  Otherwise, you need to take over the OceanBase cluster to the current OCP cluster. For more information, see Take over a cluster.

• We recommend that you replace an OBServer node only when your OceanBase cluster has at least three replicas.

• Standalone clusters do not support the OBServer node replacement operation.

Considerations

When the cluster has Cgroup enabled, if the host in the OBServer node to be replaced has an operating system kernel version earlier than 5.1.0, we recommend that you disable the cluster Cgroup. Otherwise, the system performance may drop or become unstable.

Procedure

1. Log on to the OCP console.

2. In the left-side navigation pane, click Clusters. The Clusters page automatically appears.

3. On the Clusters page, find the target cluster and click its name to go to the Overview page.

4. In the OBServers list, find the target OBServer node and click Replace in the Actions column.

5. Specify the relevant information and click Replace.

   1. Select the installation package type, which is the same as that of the current OceanBase cluster by default. If the system cannot identify the software installation package type of the OceanBase cluster, you need to select an appropriate installation package based on the version of your operating system.
   2. Select the substitute host. If no host is available in the drop-down list, you can add one. For more information, see Add a host.
   3. Complete the custom settings. Specifically, configure the OS user, path, and port number of the OBServer node. For more information, see the section about custom settings in Create a distributed cluster.
   4. Configure the startup parameters of the OBServer node. For more information, see Overview.

   Note

   • You can select only a host that matches the hardware architecture of the current cluster, and is in the same IDC as the OBServer node to be replaced.
   • When the host is offline, the cleanup job cannot be executed. The cleanup job is skipped and you must manually clean up the host environment.
   • In a production environment, we recommend that the size of the log disk be at least three times the memory size of the host. To avoid performance issues, we recommend that you do not create the data directory and the log directory on the same disk.

6. In the dialog box that appears, you can click View Task to view the progress. You can also view the task progress in Task Center.

   When the task enters the Completed state, and the status of the OBServer node is displayed as Running in the OBServer node list on the Overview page of the cluster, the OBServer node is replaced.