Configuring Alarm Policy

Last updated: 2021-05-07 17:28:03

    Log-based monitoring alarm use cases can be implemented by configuring alarm policies. This document describes how to configure an alarm policy in the CLS console.

    Prerequisites

    Configuration Process

    Step 1. Create an alarm policy

    Log in to the CLS console and click Monitoring Alarm on the left sidebar to create an alarm policy.

    Step 2. Configure a monitoring rule

    Monitoring object

    Select the log topic to be monitored and configure the corresponding analysis statement and query time range as detailed below:

    Name Description Example
    Log topic Target log topic for which to configure monitoring alarms Log topic nginx
    Analysis statement Analysis statement that acts on the log topic Example 1. Get the number of logs in the error status:
    status:error | select count(*) as ErrCount
    Example 2. Get the average request latency of the domain name:
    url:"aaa.com" | select avg(request_time) as Latency
    Query time range Data time range in which to run the analysis statement Example 1. Get the number of logs in the error status in the last 5 minutes
    Example 2. Get the average latency of the requests made in the last 1 minute

    Monitoring period

    The monitoring period indicates the frequency at which monitoring tasks are performed. CLS offers two ways to configure a period:

    Period Configuration Method Description Example
    Fixed frequency Monitoring tasks are performed at fixed intervals
    Interval: 1–1440 minutes; granularity: minute
    Monitoring tasks are performed once every 5 minutes
    Fixed time Monitoring tasks are performed at fixed time points
    Time point range: 00:00–23:59; granularity: minute
    Monitoring tasks are performed at 02:00 every day

    Step 3. Configure the alarm policy

    Trigger condition

    A trigger condition expression is used to determine whether to trigger an alarm, and an alarm will be triggered when it is met.
    CLS allows you to import analysis results by using $N.keyname.

    • $N: it indicates the Nth monitoring object in the current alarm policy (for more information, please see How do I view the number?).
    • keyname: name of the corresponding field. For example, $1.status>500 indicates triggering the alarm for the 1st monitoring object if the status field carries a value greater than 500.

    Alarm frequency

    After the trigger condition is continuously met for a certain number of times (default value: 1; value range: 1–10), CLS will trigger a notification according to the alarm frequency. Unimportant occurrences can be avoided by configuring a threshold for the number of consecutive periods. For example, configuring meeting the trigger condition for 5 consecutive periods indicates that a notification will be triggered after the trigger condition is met 5 consecutive times. If the trigger condition expression is modified, or if the expression condition is not met during computation, the number of triggered times will be zeroed.

    Notification convergence

    You can set the interval between two notifications to avoid frequently sending alarm notifications. When the execution result of a certain monitoring task meets the trigger condition, the cumulative number of triggered periods reaches the threshold, and the requirement for the notification interval is met, a notification will be sent. For example, sending an alarm notification once every 15 minutes indicates that only one alarm notification will be received within 15 minutes.

    Step 4. Configure alarm notifications

    The notification channels and objects can be set by associating a notification template. Notifications can be sent by SMS, phone calls, WeChat, WeCom, and webhook. For more information, please see Creating Notification Template.

    FAQs

    How do I view the number?

    On the monitoring rule page, the number of a monitoring object is displayed on its left. The query number for the 1st object is 1, the query number for the 2nd object is 2, and so on.