Only applications that are stateless and horizontally scalable can run on instances in an AS group. ECS instances in an AS group can be released automatically by AS, so they cannot be used to save application status information (such as session statuses) or related data (such as database data and logs).

If the application status or related data must be saved, you can store the information on separate servers.

**Table 1** Quotas
Item	Description	Default
AS group	Maximum number of AS groups per region per account	25
AS configuration	Maximum number of AS configurations per region per account	100
AS policy	Maximum number of AS policies per AS group	50
Instance	Maximum number of instances per AS group	200
Bandwidth scaling policy	Maximum number of bandwidth scaling policies per region per account	50

AS requires authentication provided by Identity and Access Management (IAM).
The AS administrator account requires permissions of the tenant guest, ECS administrator, Cloud Eye administrator, and ELB administrator.

If the Cloud Eye administrator is not available, you can only use an existing alarm to create an alarm policy. If the ELB administrator is not available, you can still use existing load balancers.

AS resources must comply with quota requirements listed in Table 2.

**Table 2** Quotas
Item	Description	Default
AS group	Maximum number of AS groups per region per account	25
AS configuration	Maximum number of AS configurations per region per account	100
AS policy	Maximum number of AS policies per AS group	50
Instance	Maximum number of instances per AS group	200
Bandwidth scaling policy	Maximum number of bandwidth scaling policies per region per account	50

What Are Restrictions on Using AS?