- What's New
- Function Overview
- Service Overview
- Getting Started
- User Guide
- Best Practices
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API Reference
- Before You Start
- API Overview
- Calling APIs
- Getting Started
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APIs
- AS Groups
- AS Configurations
- Instances
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AS Policies
- Creating an AS Policy
- Creating an AS Policy (V2)
- Modifying an AS Policy
- Modifying an AS Policy (V2)
- Querying AS Policies Bound to an AS Group
- Querying AS Policies Bound to a Scaling Resource (V2)
- Querying AS Policies (V2)
- Querying an AS Policy
- Querying an AS Policy (V2)
- Executing, Enabling, or Disabling an AS Policy
- Deleting an AS Policy
- Batch Managing AS Policies
- AS Policy Execution Logs
- Scaling Action Logs
- Quotas
- Notifications
- Lifecycle Hooks
- Tags
- API Version Query
- Application Examples
- Permissions Policies and Supported Actions
- Appendix
- Change History
- SDK Reference
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FAQs
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General
- What Are Restrictions on Using AS?
- Must I Use AS Together With ELB and Cloud Eye?
- Is AS Billed?
- Will an Abrupt Change in Monitoring Metric Values Trigger an Unnecessary Scaling Action?
- How Many AS Policies and AS Configurations Can I Create and Use?
- Can AS Automatically Scale Up or Down vCPUs, Memory, and Bandwidth of ECSs?
- What Is an AS Quota?
- How Do I Fix the Error "The key pair does not exist" When I Connect to an Instance?
- What Types of EIP and Shared Bandwidths Can Be Adjusted by AS?
- What Types of ECS and HECS Instances Can Be Scaled by AS?
- If the OS of an ECS Instance in an AS Group Is Upgraded, Can AS Automatically Add Instances with the Newest OS During the Next Scale-out Action?
- Can AS Add Yearly/Monthly ECS Instances When It Scales Out an AS Group?
- Can AS Increase Bandwidths as Required?
- AS Group
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AS Policy
- How Many AS Policies Can I Enable?
- What Are the Conditions to Trigger an Alarm-based AS Policy?
- What Is a Cooldown Period and Why Is It Required?
- Can AS Scale Capacity Based on Custom Monitoring by Cloud Eye?
- What Monitoring Metrics for an AS Group Will Be Affected If VM Tools Are Not Installed on the Instances in the Group?
- What Can I Do If an AS Policy Fails to Be Enabled?
- How Do I Install the Agent on Instances in an AS Group to Use Agent Monitoring Metrics?
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Instance
- How Do I Prevent Instances Manually Added to an AS Group from Being Automatically Removed?
- When an Instance Is Removed from an AS Group and Deleted, Is the Application Data Saved?
- Can I Add Yearly/Monthly ECS Instances to an AS Group?
- Can AS Automatically Delete Instances Added Based on an AS Policy When They Are Not Required?
- What Is the Expected Number of Instances?
- How Do I Delete an ECS Instance Created in a Scaling Action?
- Will ECS Instances Be Deleted If They Become Unhealthy?
- How Do I Handle Unhealthy Instances in an AS Group?
- Why Instances in an AS Group Keep Failing Health Checks and Getting Deleted and Recreated?
- How Do I Prevent Instances from Being Automatically Removed from an AS Group?
- Why Is an Instance that Was Removed from an AS Group and Deleted Still Displayed in the ECS List?
- Do I Need to Bind an EIP to an Instance Before I Manually Add the Instance to an AS Group?
- Can I Apply the Configurations of an Existing Instance in an AS Group to Instances to Be Added in the Future?
- Will the System Bind a New EIP or an Existing One a Newly Added ECS Instance?
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Others
- How Can I Automatically Deploy My Application on an Instance?
- How Does Cloud-Init Affect the AS Service?
- Why Can't I Use a Key File to Log In to an ECS?
- Do I Need to Configure an EIP in an AS Configuration When a Load Balancer Has Been Enabled for an AS Group?
- How Do I Enable Automatic Initialization of EVS Disks on Instances that Have Been Added to an AS Group During Scaling Actions?
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General
- Videos
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Health Check
A health check removes unhealthy instances from an AS group. Then, AS adds new instances to the AS group so that the number of instances is the same as the expected number. There are two types of AS group health checks.
- ECS health check: checks ECS instance running status. If an instance is stopped or deleted, it is considered abnormal. ECS health check is the default health check mode for an AS group. The AS group periodically uses the check result to determine the running status of every instance in the AS group. If the health check results show that an instance is unhealthy, AS removes the instance from the AS group.
- ELB health check: determines ECS instance running status using a load balancing listener. If the AS group uses load balancers, the health check method can also be ELB health check. If you add multiple load balancers to an AS group, an ECS instance is considered to be healthy only when all load balancers detect that the instance status is healthy. If any load balancer detects that an instance is unhealthy, the instance will be removed from the AS group.
In both ECS health check and ELB health check methods, AS removes unhealthy instances from the AS group. Whether a removed instance will be deleted depends on how the instance is added to the AS group.
Instance Type |
Description |
Billing Mode |
Removed If Unhealthy |
Deleted When Removed |
---|---|---|---|---|
Automatically added instances |
Instances automatically created and added to an AS group in a scaling action |
Pay-per-use By default, this type of instances is billed on a pay-per-use basis. |
Yes |
Yes |
Yearly/Monthly The billing mode of an automatically added instance can be manually changed from pay-per-use to yearly/monthly. |
Yes |
No |
||
Manually added instances |
Instances manually created and added to an AS group |
Pay-per-use |
Yes |
No |
Yearly/Monthly |
Yes |
No |
When an AS group is disabled, checking instance health status continues. However, AS will not remove instances.
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