Simple Application Server has specific limits on features and service performance. Before you use Simple Application Server, we recommend that you understand the limits to ensure that your business requirements can be met. This topic describes the usage limits of Simple Application Server resources.
Limits on servers
You can create up to 20 simple application servers within an Alibaba Cloud account.
Simple application servers do not support virtualization software or secondary virtualization.
Simple application servers do not support sound card applications.
External hardware, such as USB devices, USB security keys, external hard disks, and dongles, cannot be connected to simple application servers.
Each simple application server can have only one data disk mounted.
If a simple application server is located in the Chinese mainland and the total subscription period (including renewal periods) of the server reaches three months or longer, you can apply for up to five Internet Content Provider (ICP) filings for the server.
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 addresses cannot be configured for simple application servers.
If a simple application server is released when the server expires, the snapshots and custom images that are created based on the server are also released.
Limits on other resources
Network bandwidths
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 that have strict requirements for the quality of the public network.
Application or OS images
The
/home/staragent/and/usr/localdirectories of specific images contain pre-installed software, such as/usr/local/aegisand/usr/local/cloudmonitor. The pre-installed software consists of environment-dependent programs and libraries. You cannot modify the pre-installed software.Firewall rules
You can create up to 50 firewall rules for each 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.
Snapshots
You can create up to three snapshots for disks of each simple application server.
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 be greater than 15.
You can only manually create snapshots. The system cannot create snapshots on schedule.
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.
Custom images
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.