ALM-45431 Improper ClickHouse Instance Distribution for Topology Allocation

Description

The ClickHouseServer instance distribution does not meet the topology allocation requirements.

Attribute

Alarm ID

Alarm Severity

Auto Clear

45431

Critical

No

Parameters

Name

Meaning

Source

Specifies the cluster for which the alarm is generated.

ServiceName

Specifies the service for which the alarm is generated.

RoleName

Specifies the role for which the alarm is generated.

HostName

Specifies the host for which the alarm is generated.

Impact on the System

Some ClickHouseServer instances are unavailable.

Possible Causes

During installation or capacity expansion, the number of instances or allocation mode does not meet the topology requirements.

Procedure

  1. On MRS Manager, choose O&M. In the navigation pane on the left, choose Alarm > Alarms, locate the row that contains the alarm, and analyze the cause based on Location and Additional Information.
  2. Handle the alarm based on the additional alarm information and handling method in the following table.

    Additional Information

    Remarks

    Handling Method

    n ClickHouseServer instances should be added to other AZ.

    This alarm is generated when a single cluster is deployed in cross-AZ DR mode. The ClickHouseServer instance deployment does not meet the cross-AZ DR topology allocation requirements. As a result, some instances cannot work properly.
    1. On MRS Manager, choose Cluster > Services > ClickHouse, click the Instance tab, locate the row that contains the alarm, view the host name in Location, and find the AZ for which the alarm is generated in the AZ column based on the host name.
    2. On the Instance page, click Add Instance to add n ClickHouseServer instances to other AZs except the AZ where the alarm is generated.

    n ClickHouseServer instances should be added.

    This alarm is generated when a non-single-cluster is deployed in the default deployment mode of cross-AZ DR. The number of ClickHouseServer instances in the cluster is less than an even number. As a result, some instances cannot work properly.
    1. Determine the number (n) of ClickHouseServer instances to be added based on the alarm information.
    2. On MRS Manager, choose Cluster > Services > ClickHouse, click the Instance tab, and add n ClickHouseServer instances to the cluster.

Alarm Clearing

This alarm needs to be manually cleared after the fault is rectified.

Related Information

None

Parent topic: Alarm Reference (Applicable to MRS 3.x)