Managing MRS Role Instance Groups

Updated on 2024-09-23 GMT+08:00

View PDF

With MRS, you can easily manage instance groups by grouping multiple instances based on a specified principle, such as nodes with the same hardware configuration.

Any changes made to the configuration parameters of an instance group will apply to all instances within that group.

NOTE:

This section applies to MRS 3.x or later.

Prerequisites

You have logged in to MRS Manager. For details, see Accessing MRS Manager.

Managing MRS Role Instance Groups

On Manager, choose Cluster > Services.
Click the specified service name on the service management page.

On the displayed page, click Instance Groups.

Click and configure parameters as prompted.

Figure 1 Creating an instance group

**Table 1** Instance group configuration parameters
Parameter	Description
Group Name	Instance group name. The value can contain only letters, digits, underscores (_), hyphens (-), and spaces. It must start with a letter, digit, underscore (_), or hyphen (-) and cannot ends with a space. It can contain a maximum of 99 characters.
Role	Role to which an instance group belongs.
Copy From	Instance group where the configuration parameter values are copied from. If the value is null, default values are used.
Description	Instance group description. It can contain only letters, digits, commas (,), periods (.), underscores (_), spaces, and line breaks, and can contain a maximum of 200 characters.

NOTE:

Each instance must belong to only one instance group. When an instance is installed for the first time, it belongs to the instance group Role name-DEFAULT by default.

Click OK.
You can perform the following operations on an instance group as needed.
- Modifying an instance group: On the Instance Group page, locate the target instance group, click , and modify parameters as prompted. The default instance group cannot be modified.
- Deleting an instance group: Click Instance Groups. On the Instance Groups page, locate the row that contains the target instance group. Click . In the displayed dialog box, click OK. The default instance group cannot be deleted.
  You can delete unnecessary or unused instance groups. Before deleting an instance group, migrate all instances in the group to other instance groups. The default instance group cannot be deleted.
- Viewing instance group information: On the Instance Groups page, select a role. On the Basic page, view all instances of the instance group.
  NOTE:
  To move an instance from an instance group to another, perform the following operations:
  1. Select the instance to be moved and click Move.
  2. In the displayed dialog box, select an instance group to which the instance to be moved.
    During the migration, the configuration of the new instance group is automatically inherited. If the instance configuration is modified before the migration, the configuration of the instance will be used.
  3. Click OK.
    Restart the expired service or instance for the configuration to take effect.
- Configuring instance group parameters: On the Instance Groups page, select a role in the navigation pane, click Configuration, adjust the configuration parameters, and click Save. The configuration will take effect on all instances in the instance group.