What are restrictions on using AS?

Only applications that are stateless and horizontally scalable can run on ECSs in an AS group. ECSs in an AS group can be released automatically by AS, so they cannot be used to save application status information (such as session) or related data (such as database data and logs). If the application status or related log data must be saved, you can store the information on separate ECSs.

Must I use AS together with ELB and Cloud Eye (CES)?

AS can work independently or in conjunction with ELB and CES. CES does not require additional fees and is enabled by default. ELB is not enabled by default, but you can enable it manually if needed, for example, if distributed clusters are required.

Will an abrupt change in monitoring indicators trigger an unnecessary scaling action?

No. No. Monitoring data used by AS is obtained from CES. The monitoring period can be set to multiple intervals, such as 5 minutes, 20 minutes, or 1 hour. An abrupt change in monitoring data values will not impact scaling actions.

In addition, AS alarm policies allow you to configure a cooldown period to prevent unnecessary scaling actions caused by frequently reported alarms. You can customize the cooldown period as needed.

How many policies and AS configurations can I create and use?

You can create up to 10 AS groups and 10 AS configuration items. An AS group can use 1 AS configuration and 10 AS policies at a time.

How many AS policies can I enable?

You can enable one or multiple AS policies.

Can the system automatically delete the ECSs added based on an AS policy when they are not required?

Yes. They can be automatically deleted if an AS policy has been added to delete the ECSs.

How do I automatically deploy applications?

You need to create a private image for your OS, applications and configurations. After you select the private image in the AS configuration, the ECS added by AS can automatically deploy your applications.

Will AS be disabled after the ECS is shut down?

AS will not be disabled.

How do I prevent ECSs from being automatically removed from an AS group?

You can enable instance protection for one or more healthy instances in an AS group. After the configuration, the protected instances will not be removed when the AS scales down resources. You can also set the minimum number of instances for an AS group and use an instance removal policy to ensure that the AS group always has some in-service ECS instances.

How do I automatically initialize a newly added ECS data disk for AS?

For details, see Initializing a Data Disk.

Auto Scaling

Operation