Docs

Load Balancer

Health check log

Health check log overview

Overview

CLB provides health check log capabilities. The health check log collects log information about backend server health check status changes and delivers it to Torch Log Service for storage, making it easy for you to view as needed, analyze the cause of exceptions, and quickly locate problems.

tip

A health check log is generated only when there is a change in the backend server's health check status (i.e., from normal to exception, or from exception to normal).

Log fields

The health check log data is displayed in the form of key-value pairs, that is, {key: value}. The fields in the log and their meanings are described as follows:

Parameter	Description
cause	Cause for the health check failure. When the health check fails, the health check log contains this field.
destination	Destination of the health check, that is, the backend server. Format is: private IP address of the backend server instance:Backend port, for example 192.168.3.114:80.
domain	Domain name for the health check of a Layer 7 listener. This field is absent in the health check log of a Layer 4 listener.
instanceId	ID of the CLB instance.
origion	Source of the health check, that is, CLB. Format: [Private IPv4 address of the CLB instance,Private IPv6 address of the CLB instance]:listening port, For example [192.168.2.128,2000:1000:dff:ff01:1:1200:2:928]:80.
protocol	Protocol used for the health check, which is TCP, UDP, or HTTP.
result	Health check result, which is succeed or failed.
time	The time when the health check message was sent, default is Beijing time, for example: 2021-08-10T17:39:29 +08:00.
url	URL for the health check of a Layer 7 listener. This field is absent in the health check log of a Layer 4 listener.

Billing Description

CLB health check log generation does not incur a fee, but Tinder Log Service charges a fee. For details, please refer to Billing.

Constraints

One account can be used to create only one log project in the CLB service.

You can create up to 100 log topics for a log project.

A log topic can be associated with up to 60 CLB instances.

The log projects and log topics created by the CLB cannot be deleted in the Tinder Log Service console, only the CLB console deletes are supported.

Use process

Cross-service authorization and log project creation: Grant the relevant TLS operation permissions to the cross-service role **ServiceRoleForCLBLogDelivery** of the CLB instance. After successful authorization, a log project is automatically created.

Create log topic: Create a log topic to store and manage the CLB health check logs.

View health check logs: View the CLB health check logs as needed.

Last updated: 2025.09.26 16:51:25