Alert-related concepts

This topic describes the concepts of alert target, alert scope, alert item, alert, alert item group, alert level, template, alert aggregation, and alert clearance.

Alert target

An alert target is a target that is monitored by the alert task and uniquely identifies an alert. It can be an OceanBase cluster, a server, or a service.

Based on the alert item, an alert target can be a tag value or a combination of tag values, such as obregion=obocp:svr_ip=*.*.*.*identifies a server in an OceanBase cluster or OceanBase Cloud Platform (OCP) cluster.

Alert scope

The alert scope defines the scope of an alert and is consistent with the metric scope. For example, when the CPU utilization exceeds the threshold, it can be a problem for the entire cluster, the tenant, or a single server.

Valid values of the alert scope:

• Cluster

• Tenant

• Server

Alert item

An alert item is the metadata of an alert. It consists of many elements such as the alert type, name, trigger rule, alert overview template, and alert details template.

Alert items can be divided into two types based on how they are generated:

• Expression-triggered alert items : Alert items that are created on the console and generated by the alert rule engine based on the monitoring metrics.

• Custom-triggered alert items : Alert items that are automatically triggered by other components.

For expression-triggered alert items, the alert rule expressions are configured in the alert items. For custom-triggered alert items, the alert rule expressions are empty.

Alert

An alert is a notification generated by the system when an alert item occurs on a notification target.

For example, when the alarm_b alert item occurs on Server A (an alert target), the alert signal is sent every minute. However, it is counted as one alert on OCP, and only one record is displayed on the Alert Events tab.

Alert item group

You can set multiple groups for each alert item for easy configuration of alert subscriptions.

Alert level

Each alert item has an alert level.

Template

Templates are used to generate dynamic content by using variables during the runtime. They can be used for:

• Generating alerts (configuring the alert overview and and details templates for alert items)

• Notification content (configuring the message and message aggregation templates for channels)

• Channel parameters (for example, configuring the Header and Body content templates in the HTTP channel)

Sample template:

• alarm_summary: The CPU utilization of ${alarm_target} exceeds the threshold.``

• alarm_description: The CPU utilization of ${alarm_target} has exceeded ${alarm_threshold} for ${alarm_duration}.

For more information about the supported template variables, see OCP alert template variables.

Alert aggregation

To avoid alert storms caused by too many alerts, you can aggregate the alert channels.

Aggregation rules:

• Aggregate OceanBase log alerts by alert type, log error code, and OceanBase cluster.

• Aggregate other OceanBase alerts by alert type and OceanBase cluster.

• Aggregate application alerts by alert type and alert target.

Alert clearance

An alert is cleared when a fault is recovered. After that, the monitoring module identifies that the fault is resolved and notifies the alert service, or the alert service clears the alert automatically after the clearance timeout expires.

The logic of clearing alerts after a timeout period:

• Each alert item has a check cycle and ignorance cycle.

• During the new check cycle, the monitoring module calls the alert API to set the alert item as cleared if it finds that the alert item meets the clearance criteria.

• When the ignorance cycle expires, the alert item is considered cleared if the alert item is no longer reported.

Alert API

OCP provides HTTP-based RESTful APIs to help you manage OceanBase resources and develop your applications. Alert APIs describes the API operations and syntax and provides some examples. The API document is intended for developers. Before you call an API, make sure that you have fully understood the OCP-related concepts.

You can call an API based on the access method.

• API call description

• Example of an alert API call

Quick start

Alerts and alert notifications are important monitoring features in OCP. Users of different roles perform different operations when they use these features.

After OCP is deployed, an administrator must perform the initial settings of the alert modules, such as adding alert items and configuring alert channels. An administrator also manages alert items and alert channels based on business requirements. An OCP user can subscribe to alerts of different modules, view alert events and notifications, or choose to block some alerts.

We recommend that you perform the following steps to configure the alert module in OCP:

1. If you log on as an administrator:

   1. Configure alert channels.

   2. Create alert items.

2. If you log on as a general user:

   1. Subscribe to alerts.

   2. View alert events.

   3. Block some alerts (optional).