Simple Application Server limitations

Limit

Description

Number of instances

The default quota for the total number of Simple Application Server instances, Simple Application Load Balancer instances, Simple Container Service instances, and Simple Database Service instances per Alibaba Cloud account in a single region is 50. To request a quota increase, see View or increase an instance quota.

Virtualization software and secondary virtualization

Virtualization software and secondary virtualization are not supported.

Sound card applications

Sound card applications are not supported.

Attaching external hardware devices

You cannot attach external hardware devices, such as hardware dongles, USB flash drives, external hard drives, or USB security keys.

ICP filing service numbers

For each instance in a Chinese mainland region subscribed for three months or longer (including renewals), you can apply for up to five ICP filing service numbers.

Item

Description

Available regions

Available only in Chinese mainland regions on the China site.

Data disk attachment

Attaching data disks is not supported.

Upgrade

Upgrading configurations is not supported.

Tokens resource plan

The Tokens resource plan is tightly coupled with the cloud server. It is purchased in a prepaid manner together with the instance and cannot be purchased separately. When the resource plan is exhausted, the model service becomes unavailable (throttled to 0). Usage is reset at the start of the next billing cycle.

Models

To optimize resource utilization for Agent-specific instances, legacy models are periodically retired based on model iteration and upgrades. From the date the retirement notice is issued, the RPM (requests per minute) and TPM (tokens per minute) of the models to be retired are gradually reduced. From the official retirement date, model inference services are no longer supported, and applications or services that call the retired model no longer return results.

Refund

The cloud server is refunded based on the residual value of the remaining subscription period, and the Tokens resource is refunded based on the residual value of the remaining usage. For the five-day no-reason refund scenario, refunds are not supported if any Tokens resource has already been consumed.

Limit

Description

Custom images

The quota for custom images per Alibaba Cloud account is three times the number of your instances, up to a maximum of 15.

Cross-account image sharing

• You can share custom images with other accounts only within the same region. Cross-region sharing is not supported.

• Each custom image can be shared with up to 10 primary Alibaba Cloud accounts. Sharing with RAM users is not supported.

• You cannot share images between Alibaba Cloud accounts on the China site and the International site.

• When you share a custom image created from an instance that has a data disk, the data disk is not included in the shared image.

For more information, see Share custom images across accounts.

Application or system images

The /home/staragent/ and /usr/local directories in some images contain pre-installed software, such as /usr/local/aegis and /usr/local/cloudmonitor. This software consists of programs and library files that are environment dependencies. Do not modify these files.

Releasing custom images

When you release a Simple Application Server instance, any custom images created from it are also released.

Limit

Description

Number of snapshots per instance

You can create up to three snapshots per instance.

Maximum number of snapshots per account

The snapshot quota per Alibaba Cloud account is three times the number of your instances, up to a maximum of 15.

Scheduled snapshots

You can only create snapshots manually; scheduled snapshots are not supported.

Rolling back a disk with a snapshot

Snapshots created before a system reset or an image change are retained but cannot be used to roll back the disk.

Releasing snapshots

When a Simple Application Server instance expires and is released, its snapshots are also released.

Downloading or exporting snapshots

You cannot download or export snapshots.

Limit

Description

Public IP address

By default, each Simple Application Server instance is assigned one public IP address. This address cannot be changed and is not retained after the instance expires.

IPv6 address

Simple Application Server does not support IPv6 addresses.

Bandwidth

• Simple Application Server provides symmetrical inbound and outbound bandwidth, where traffic in both directions shares a single peak bandwidth limit specified in your plan. For example, if you purchase a plan with 200 Mbps of bandwidth, the peak inbound and outbound bandwidth are both 200 Mbps. However, the total bandwidth for both directions cannot exceed 200 Mbps. This means you cannot reach the maximum bandwidth limit for both directions at the same time.

• The public bandwidth specified in a Simple Application Server plan is a peak value and not a guaranteed performance commitment. During periods of high traffic, resource contention may lead to bandwidth limitations or packet loss. This service is not suitable for applications that require a guaranteed high-quality public network connection. For such applications, we recommend that you purchase an ECS instance with a fixed-bandwidth billing plan.

Firewall

• You can create up to 50 firewall rules per instance.

• Port 25 on Simple Application Server instances is blocked for outbound email. If you need to send email, use port 465 instead.

For more information, see Manage firewalls.

VPC connection

By default, all Simple Application Server instances under the same Alibaba Cloud account and in the same region can communicate with each other over the internal network. However, they cannot communicate with other Alibaba Cloud services in a VPC, such as ECS and ApsaraDB instances. To enable this communication, you must set up a VPC connection. For more information, see Manage VPC connections.