Usage limits of Simple Application Server resources - Simple Application Server

Simple Application Server has specific limits on features and service performance. Before you use Simple Application Server, we recommend that you understand these limits to ensure that your business requirements can be met. This topic describes the limits of Simple Application Server resources.

Servers

Limit	Description
Instance quota	By default, you can purchase a maximum of 50 simple application servers in a region for an Alibaba Cloud account. For information about how to increase the quota, see View or increase instance quotas.
Virtualization software and secondary virtualization	Simple application servers do not support installation of virtualization software and secondary virtualization.
Sound card applications	Simple application servers do not support sound card applications.
External hardware devices	External hardware devices, such as USB devices, USB security keys, external hard disks, and dongles, cannot be connected to simple application servers.
Service identification codes for Internet content provider (ICP) filings	For simple application servers in regions in the Chinese mainland with a subscription duration of three months or more (including accumulated renewal period), you can apply for a maximum of five service identification codes for ICP filings for each server.

Images

Limit	Description
Custom image	The maximum number of custom images that can be retained in an Alibaba Cloud account is triple the number of simple application servers in the account. The value cannot be greater than 15.
Cross-account custom image sharing	You can share images across accounts only within the same region. You cannot share images across regions. A custom image can be shared with a maximum of 10 Alibaba Cloud accounts. You cannot share a custom image with RAM users. Images cannot be shared between accounts on the China site (aliyun.com) and accounts on the international site (alibabacloud.com). If you share a custom image that contains a data disk across accounts, the custom image received by the peer account does not contain the data disk. For more information, see Share a custom image across accounts.
Application images or OS images	Some images have pre-installed software in the `/home/staragent/` and `/usr/local` directories, such as `/usr/local/aegis` and `/usr/local/cloudmonitor`. These software programs are environment-dependent programs and library files. Do not modify the software programs.
Release of custom images	If a simple application server is released when it expires, the custom images that are created based on the server are also released.

For more information about custom images, see Manage custom images.

Storage

Limit	Description
Maximum number of system disks on a single simple application server	1
Maximum number of data disks that can be attached to a single simple application server	1
Data disk size	0 to 16380 GiB
Data disk mount point	`/dev/vdb`
Detachment of a data disk	A data disk and its associated server expire at the same time. The data disk is bound to the server and cannot be detached.
Renewal of data disks	After a data disk is attached to a simple application server, the data disk must be renewed together with the simple application server.

Snapshots

Limit	Description
Maximum number of snapshots that can be created for a single simple application server	3
Maximum number of snapshots in an Alibaba Cloud account	The maximum number of snapshots that can be retained in an Alibaba Cloud account is triple the number of simple application servers in the account. The value cannot exceed 15.
Scheduled snapshots	You can only manually create snapshots. The system cannot create scheduled snapshots.
Disk roll-back based on a snapshot	If a simple application server is reset, the snapshots that are created before the server is reset are retained, but the snapshots cannot be used to roll back the disks of the server.
Release of snapshots	If a simple application server is released when it expires, the snapshots that are created based on the server are also released.
Snapshot download or export	You cannot download or export created snapshots.

For more information about snapshots, see Manage snapshots.

Network

Limit	Description
Public IP address	By default, each simple application server is assigned a public IP address. You cannot change the public IP address. You cannot retain the public IP address when the corresponding simple application server expires.
IPv6 address	IPv6 addresses cannot be configured for simple application servers.
Bandwidth	Bandwidth limits vary based on whether the peak outbound bandwidth exceeds 10 Mbit/s. If the peak outbound bandwidth in the plan that you purchased for your simple application server is less than or equal to 10 Mbit/s, the inbound bandwidth of the server is 10 Mbit/s. If the peak outbound bandwidth in the plan that you purchased for your simple application server exceeds 10 Mbit/s, the inbound bandwidth of the server is equal to the peak outbound bandwidth. The public bandwidth in the plan that you purchased for your simple application server is used as the maximum inbound and outbound public bandwidths instead of guaranteed performance. If resource contention occurs during peak hours, the maximum public bandwidths may not be reached. Simple application servers are not suitable for scenarios in which you have strict requirements for the quality of Internet connections. If you have strict requirements for the quality of Internet connections, we recommend that you us Elastic Compute Service instances of which bandwidths are billed.
Firewall	You can create a maximum of 50 firewall rules for a single simple application server. Port 25 on simple application servers cannot be used to send emails to external resources. If you want to send emails, use port 465. For more information, see Manage firewalls.
Service interconnection	By default, all simple application servers that belong to the same Alibaba Cloud account in the same region can communicate with each other over virtual private clouds (VPCs). By default, simple application servers cannot communicate with other Alibaba Cloud services in VPCs, such as ECS instances and ApsaraDB services, over VPCs. You can enable the service interconnection feature to implement connectivity between these services. For more information, see Manage service interconnection.