This topic describes how to analyze logs that are collected by Log Service and configure an alert rule for the logs.
Prerequisites
On-premises logs are collected and stored in Log Service. For more information, see Log Service.
Procedure
当您首次使用日志监控功能时，需要授权云监控访问日志服务的权限。
Log on to the Cloud Monitor console.
在左侧导航栏，单击日志监控。
在云监控服务关联角色对话框，单击确定。
Create a log monitoring metric.
In the upper-left corner of the Log Monitoring page, click Create Log Monitoring Metric.
In the Associate Resource step, select the resources that you want to associate and click Next.
In the Define Metric step, set the parameters and click Next.
The following table describes the parameters.
Parameter
Description
Metric Name
The name of the metric.
Unit
The unit of the metric.
Computing Cycle
The statistical period of the metric. Unit: minutes. Valid values: 1, 2, 3, 4, 5, 10, 15, 20, 30, and 60.
Statistical Method
The function that is used to aggregate the log data of a statistical period. If the value of the specified field is a numeric value, you can use all statistical methods. Otherwise, you can use only the Count and countps methods to aggregate data. Valid values:
Count: calculates the number of values of the specified field within a statistical period.
Sum: calculates the sum of the values of the specified field within the last minute.
Max: calculates the maximum value of the specified field within a statistical period.
Min: calculates the minimum value of the specified field within a statistical period.
Average: calculates the average of the values of the specified field within a statistical period.
countps: calculates the number of values of the specified field divided by the total number of seconds of a statistical period.
sumps: calculates the sum of the values of the specified field divided by the total number of seconds of a statistical period.
distinct: calculates the number of unique values of the specified field within a statistical period.
Extended Field
Performs basic operations on calculation results. For example, after you set the Statistical Method parameter to aggregate log data, you specify a field as TotalNumber to calculate the total number of HTTP requests. At the same time, you specify another field as 5xxNumber to calculate the number of HTTP requests whose status code is greater than 499. In this case, you can specify an extended field to calculate the server error rate by using the following formula: 5XXNumber/TotalNumber × 100%.
Log Filter
Filters log data. This parameter is equivalent to the WHERE clause in SQL. For example, if you want to monitor logs in which the value of the level field is ERROR, set the parameter to
level=Error.The name of the log field that you want to use to filter data cannot contain Chinese characters.
Group-by
The dimension based on which data is aggregated. This parameter is equivalent to the GROUP BY clause in SQL.
Log data is grouped by specified dimension. If you do not specify a dimension, all data is aggregated based on the specified aggregate function.
For more information, see GROUP BY clause.
Select SQL
Converts the statistical methods that you specify to an SQL statement. This parameter indicates how data is processed.
Application Group
The name of the application group. The metric is added to the specified application group.
In the Define Metric step, click Preview to preview the aggregated log data of the last minute by using the specified statistical methods. Only the most recent 100 logs of the last minute are analyzed. The following figure shows a sample preview result.
In the Configure Alert Rule step, set the parameters and click Next.
In the Creation Result step, click Close.
View the monitoring data of the metric.
After you create the log monitoring metric, wait for 3 to 5 minutes. On the Log Monitoring page, find the metric whose monitoring chart you want to view and click the
icon in the Actions column. View the alert notifications that are sent for the metric.
If the metric meets the specified condition in the alert rule, Cloud Monitor sends an alert notification.