This topic describes how to add a read-only column store node in the PolarDB console. Learn about the Supported versions and Usage notes before you proceed.
Supported versions
An Enterprise Edition cluster that meets one of the following requirements:
PolarDB for MySQL 8.0.1 whose revision version is 8.0.1.1.22 or later.
PolarDB for MySQL 8.0.2 whose revision version is 8.0.2.2.12 or later.
A Standard Edition cluster that uses the X86 CPU architecture and meets one of the following conditions:
PolarDB for MySQL 8.0.1 whose revision version is 8.0.1.1.38 or later
PolarDB for MySQL 8.0.2 whose revision version is 8.0.2.2.19 and later.
Usage notes
For a Multi-master Cluster (Limitless) cluster, change the value of the
loose_polar_enable_imci_with_mmparameter toONand then add a global read-only column store node to the cluster. For more information about the parameter, see Configure cluster and node parameters.For a cluster in a global database network (GDN), contact us for assistance before you can add a read-only column store node.
The In-Memory Column Index (IMCI) feature can be used together with the Voting Disk Service (VDS) module of the failover with hot replica feature only under these conditions. For more information about the feature, see Overview.
For a cluster whose revision version is 8.0.1.1.42 or later or 8.0.2.2.23 or later:
If a cluster contains a read-only node where the failover with hot replica feature is enabled, you can add read-only column store nodes to the cluster.
If a read-only column store node already exists in a cluster, you cannot enable the hot standby feature for any read-only node in the cluster.
For a cluster whose revision version is earlier than 8.0.1.1.42 or earlier than 8.0.2.2.23, the IMCI feature cannot be used together with failover with hot replica feature.
If a cluster contains a read-only node for which the failover with hot replica feature is enabled, you cannot add read-only column store nodes to the cluster.
NoteIf you want to add a read-only column store node to the cluster, contact us to disable VDS. When VDS is being disabled, all nodes in the cluster are automatically restarted.
If a read-only column store node already exists in a cluster, you cannot enable the hot standby feature for any read-only node in the cluster.
Procedure
You can use one of the following methods to add read-only column store nodes:
Add a read-only column store node in the console
Log on to the PolarDB console. Click Clusters in the left-side navigation pane. In the upper-left corner of the page, select the region in which the cluster resides and then find the cluster in the list. Go to the Add/Remove Node dialog box by using one of the following methods:
On the Clusters page, click Add/Remove Node in the Actions column.
On the Basic Information page of the cluster, click Add/Remove Node in the Database Nodes section.
Select Add Read-only IMCI Node and click OK.
Add a read-only column store node and complete the payment.
Click +Add an IMCI Node and select the node specifications from the drop-down list.
Set the Switching Time parameter.
(Optional) View the terms of service and service level agreement.
Click Buy Now.
After you complete the payment, go to the cluster details page. The node is successfully added after it enters the Running state.
Add a read-only column store node when you purchase a cluster
In the cluster configuration page of the PolarDB buy page, find the Nodes parameter and set Read-only Column Store Nodes. After you complete the purchase, check whether read-only column store node is added. For more information, see the Results section of this topic.
Results
Log on to the PolarDB console, go to the Basic Information page of the cluster, and check whether the read-only column store node is added.
In the preceding figure, Read-only Columnar Node is the new column store node, and Read-only Node is the original row store node.
Related API operations
API | Description |
Adds a read-only node to a PolarDB cluster. |