This topic describes the limits of the alerting feature in Log Service.

Alerting (New)

Category Item Limit
Monitoring and alerting Number of alert monitoring rules You can create up to 100 alert monitoring rules in each project.

If you want to increase the quota, you can submit a ticket. The quota can be increased to 200 in each project.

Query statements For more information about the limits on query statements, see Query and analysis.
Results of a single query statement If more than 1,000 rows are returned for a single query statement, only the first 1,000 rows are used for a set operation.

If you specify three query statements but do not select No Merge, only the first 100 rows that are returned for each query are used for set operations.

Number of query statements for set operations You can specify one to three query statements for set operations.
Field value length If the length of a field value exceeds 1,024 characters, the field value is truncated, and only the first 1,024 characters are used for analysis.
Time range for a query statement The time range for a query statement cannot exceed 24 hours.
Alert management Regions in which incident management is supported Incident management is supported in the following regions:
  • Chinese mainland: China (Chengdu), China (Heyuan), China (Hohhot), China (Guangzhou), China (Qingdao), China (Ulanqab), China (Hong Kong), China (Hangzhou), China (Shenzhen), China East 2 Finance, and China South 1 Finance
  • Outside the Chinese mainland: Singapore (Singapore), UAE (Dubai), Malaysia (Kuala Lumpur), India (Mumbai), Japan (Tokyo), Germany (Frankfurt), UK (London), Australia (Sydney), US (Silicon Valley), and US (Virginia)
Number of incidents Up to 1,000 incidents can be retained in 30 days. If the number of incidents exceeds 1,000, the earliest incident is automatically overwritten by the latest incident.
Number of incident comments Up to 10 comments can be added for each incident. If the number of comments for an incident exceeds 10, the earliest comment is automatically overwritten by the latest comment.
Notification management Notification methods
  • Voice Call
    This notification method supports only mobile phone numbers in the Chinese mainland, which are prefixed with 86.
    Note
    • If a voice call is not answered, Log Service sends a text message.
    • You are charged for a voice call regardless of whether the call is answered. You are not charged for the text message that is sent upon a non-answered voice call.
  • DingTalk
    • Only custom keywords are supported in the security settings of a DingTalk chatbot.
    • Each DingTalk chatbot can send up to 20 alert notifications every minute.
  • Enterprise WeChat
    • Only custom keywords are supported in the security settings of an Enterprise WeChat robot.
    • Each Enterprise WeChat robot can send up to 20 alert notifications every minute.
  • Lark
    • Only custom keywords are supported in the security settings of a Lark robot.
    • Each Lark robot can send up to 20 alert notifications every minute.
    • You can set Notified Contacts to No Reminder or All. You cannot set the parameter to Specified Members.
  • Webhook-Custom
    • The webhook URL must be accessible over the Internet.
    • If a webhook is successfully invoked, the HTTP status code 200 is returned. If the HTTP status code 200 is not returned, Log Service considers the request as failed.
    • IP address whitelists are not supported. For more information, see FAQ about custom webhooks.
  • Function Compute

    Only the functions that start with sls-ops- are supported.

For more information, see Notification methods.

Notification content
  • SMS Message

    A notification can contain up to 256 characters.

  • Voice Call

    A notification can contain up to 256 characters.

  • Email

    A notification cannot exceed 8 KB in size.

  • DingTalk

    A notification cannot exceed 8 KB in size.

  • Enterprise WeChat
    • A notification cannot exceed 4 KB in size.
    • If you set Notified Contacts to All or Specified Members, Enterprise WeChat supports only plain text in alert notifications, instead of the Markdown syntax.
  • Lark

    A notification cannot exceed 8 KB in size.

  • Slack

    A notification cannot exceed 8 KB in size.

  • Webhook-Custom

    A notification cannot exceed 16 KB in size.

  • Notifications

    A notification cannot exceed 8 KB in size.

  • Function Compute

    A notification cannot exceed 16 KB in size.

  • EventBridge

    A notification cannot exceed 16 KB in size.

Alert template variables The value of a variable cannot exceed 2 KB in size. If a value exceeds 2 KB in size, the value is truncated.
Notification quota A recipient can receive up to 9,999 emails, text messages, or phone calls per day. For more information, see Configure notification quotas.

Alerting (Old)

Item Description
Associated query statements You can associate an alert rule with a maximum of three query statements.
Field value size If a field value exceeds 1,024 characters in length, Log Service extracts only the first 1,024 characters for data processing.
Trigger condition The trigger condition has the following limits:
  • Each trigger condition must be 1 to 128 characters in length.
  • If a query result includes more than 100 rows, Log Service only checks whether the first 100 rows meet the trigger condition.
  • Log Service checks whether a trigger condition is met for a maximum of 1,000 times for the specified query statements.
Query time range The maximum time range that you can specify for each query is 24 hours.
Voice calls If a voice call is not answered, Log Service sends an SMS notification.

You are charged only once for the voice call regardless of whether the call is answered. The SMS notification does not incur fees.