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Simple Application Server:FAQ

Last Updated:Dec 04, 2025

This topic answers frequently asked questions about Simple Application Server.

In which regions are simple application servers deployed?

The regions available for Simple Application Server differ between the Alibaba Cloud China Website (www.aliyun.com) and the Alibaba Cloud International Website (www.alibabacloud.com). For more information, see Supported regions.

What are the statuses of simple application servers?

The status of a simple application server varies based on how you query it. A console status is displayed in the Simple Application Server console. An API status is returned when you call the ListInstances operation.

Server statuses are classified as stable or intermediate. An intermediate status is a transitional state that occurs before a server enters a stable status. If a server remains in an intermediate status for an extended period, an error has occurred.

The following table describes the server statuses.

Console status

API status

Status property

Description

Starting

Starting

Intermediate

The intermediate status of a server after it is created, started, or restarted. The server then enters the Running state.

Running

Running

Stable

The simple application server is running as expected. The server can be accessed only in this state.

Note

A simple application server that is about to expire is also in this state. Pay attention to the remaining subscription duration of the server.

Stopping

Stopping

Intermediate

The intermediate status of a server after you stop it. The server then enters the Stopped state.

Resetting

Resetting

Intermediate

The intermediate status of a server after you reset its system.

Upgrading

Upgrading

Intermediate

The intermediate status of a server after you upgrade its configuration.

Stopped

Stopped

Stable

The stable status of a simple application server after it is stopped.

Disabled

Disabled

Stable

The simple application server is locked due to reasons such as overdue payments or security risks. Renew the server as needed. For more information, see Renewal policy. You can also submit a ticket to request to unlock the server.

Can I upgrade the configuration of a simple application server?

Yes, you can. If your server's configuration no longer meets your business needs, you can upgrade it to improve performance. For more information, see Upgrade a simple application server.

Can I transfer a simple application server to another Alibaba Cloud account?

No, you cannot.

What do I do if the memory and system disk usage are not displayed when I view the monitoring information of a server in the console?

In the Simple Application Server console, the CloudMonitor agent collects memory and system disk data. Operations such as resetting the system may cause the CloudMonitor agent to become invalid. If you cannot query the server's memory and system disk usage in the Metrics section of the console, you must manually install the CloudMonitor agent. For more information, see Install and uninstall the CloudMonitor agent.

Why is my server in the Disabled state?

A simple application server enters the Disabled state if the instance has expired, is stopped due to an overdue payment, or is locked because of security risks.

  • If your instance is at risk of being stopped because of expiration or an overdue payment, the system sends you a reminder or notification. Renew the instance promptly to avoid business disruptions. For more information, see Overdue payments.

  • If the instance is locked, submit a ticket to request that it be unlocked.

How do simple application servers ensure data security?

Simple Application Server ensures data security using the triplicate technology of cloud disks and the snapshot feature. The details are as follows:

  • Triplicate technology of cloud disks

    The data protection mechanism for cloud disks is implemented using Alibaba Cloud's triplicate technology. This technology uses a distributed file system to provide stable, efficient, and reliable random data access for simple application servers, which ensures 99.9999999% data reliability. For more information, see Triplicate technology of cloud disks.

  • Snapshot feature

    Simple Application Server provides a snapshot backup feature. You can create snapshot backups or use snapshots to restore the cloud disk data of your server at any time. For more information about how to back up and restore data from snapshots, see Manage snapshots.

How do simple application servers ensure network security?

Simple Application Server ensures network security using default network configurations and firewall features. The details are as follows:

  • Default network configuration (VPC)

    Simple application servers use a virtual private cloud (VPC) by default. Multiple simple application servers under the same account and in the same region are in the same VPC by default. Service interconnection between multiple servers can be achieved over the internal network, but by default, they are not interconnected with other products under the same account over the internal network. For example, you cannot directly associate an ApsaraDB RDS instance over a VPC.

  • Firewall feature

    Simple Application Server provides a firewall feature. Ports 22, 80, and 443 are open by default, while other ports are closed. You can select the range of ports to open based on your needs. For more information, see Manage firewalls.

How do I harden the operating system?

You can ensure the security of your operating system by managing access security, hardening the operating system, and implementing advanced security measures. For more information, see Operating system security.

Can simple application servers defend against network attacks?

Simple Application Server is equipped with Alibaba Cloud Security to defend against DDoS flood attacks. When a network attack occurs, the Alibaba Cloud monitoring system automatically detects and scrubs unusual traffic. If the attack volume is very large, Alibaba Cloud applies blackhole routing to protect your simple application server instance. For security reasons, you should install protection software to enhance security and close infrequently used ports. For more information, see Network Security.

What security services does Alibaba Cloud offer?

Alibaba Cloud Security Center, combined with the powerful data analytics capabilities of the Alibaba Cloud platform, provides one-stop security services, such as security vulnerability detection, web Trojan detection, host intrusion detection, and defense against DDoS flood attacks.

For more information about security services, see the Security Products page.

How do I detect mining programs on a server?

Based on the features of mining programs, you can use the following methods to detect if a server is being used for mining.

  • Check if the server's CPU is functioning normally.

    Note

    If your server's CPU utilization increases significantly, for example, to over 80%, and an unknown process continuously sends network packets, you can determine that a mining threat exists on your server.

  • Log on to the Security Alerts page of the Security Center console and check for attack alerts in the processing list.

For more information, see Best practices for defending against mining programs and Best practices for handling mining programs.

How do I handle mining programs or request to unblock a server?

  • Solution 1: Handle mining programs

    You can check for mining programs in Security Center and mining worms in Cloud Firewall. For more information, see Best practices for defending against mining programs and Best practices for handling mining programs.

  • Solution 2: Request to unblock the server

    A server may be locked because of mining viruses or attacks. You can request to unblock it. For more information, see Penalty List.

    Note the following points about unblocking requests:

    • You can request self-service unblocking only once.

    • After the unblocking request is approved, the system automatically performs a check after three days. If mining behavior is detected again, the server is blocked again and cannot be unblocked.

    • After the server is unblocked, back up your data promptly.

Why is the server download speed slow at times? Is it throttled?

The public bandwidth of a Simple Application Server plan specifies the upper limit for inbound and outbound traffic. It is not a guaranteed performance metric. During peak hours, resource contention may cause bandwidth throttling and packet loss. Simple application servers are not suitable for scenarios that have high requirements for public network quality. If your business has high requirements for public network quality, we recommend that you purchase an Elastic Compute Service (ECS) instance that uses the pay-by-bandwidth billing method.

Can a simple application server connect to ApsaraDB RDS over a VPC?

Yes, they can. By default, multiple simple application servers that belong to the same account and are in the same region are in the same VPC and can communicate with each other over the internal network. However, they cannot communicate with other products over the internal network by default.

Why is the network latency high when I access a website or application on the server?

Factors such as the server's region and your local network environment can cause high network latency or even inaccessibility. For troubleshooting and solutions, see The network speed of a simple application server is slow and does not match the expected bandwidth.

How do I obtain the public IP address of a simple application server?

You can obtain the public IP address from the simple application server card in the console. For more information, see View simple application server information.

Can I change the public IP address of a simple application server?

No, you cannot. Each simple application server is configured with one public IP address by default. This public IP address cannot be changed or retained after the server expires.

Why is the public IP address of an instance purchased in the China (Hong Kong) region detected as not belonging to Hong Kong?

The IP address databases of third-party or game service providers may have significant update delays. The geographic location of a network IP address is related to its announcement. The previous geographic location of an IP address does not represent its current location. The region that you specified at the time of purchase is the correct one.

Can port 25 be unblocked for a simple application server?

No, it cannot. For security reasons, you cannot use port 25 of an Alibaba Cloud simple application server to send emails externally. To send emails, use port 465 instead. For more information, see Manage firewalls.

Why is a simple application server inaccessible from a specific IP address?

Possible reasons are as follows:

  • The corresponding firewall port on the simple application server is not open. For example, to remotely connect to a MySQL database on the server and the firewall does not allow traffic on the default MySQL port 3306, you will receive a connection timeout error. For information about how to set firewall rules, see Manage firewalls.

  • The IP address may be blocked by Security Center if Alibaba Cloud determines that it is engaging in attack behavior against cloud resources, such as frequent website access or other improper operations. If you are sure that the IP address is safe and its blocking by Security Center affects your business operations, submit a ticket to have it unblocked.

Why does creating a server from a custom image fail?

To prevent server creation from failing, avoid the following operations before the server is created:

  • Deleting the corresponding custom image.

  • Deleting the source snapshot of the custom image.

  • Resetting the system or replacing the image of the source simple application server for the custom image.

  • Releasing the source simple application server of the custom image.

How do I change the operating system of a simple application server?

Simple Application Server provides application images and OS images that you can use to create servers.

  • Application image: Simple Application Server provides a variety of application images. You can use different application images to quickly deploy application environments or websites.

  • OS image: Simple Application Server provides Windows Server OS images and mainstream Linux OS images. You can use these images to create a clean, secure, and stable runtime environment.

You can change the operating system of your simple application server based on your needs. For more information, see Reset the system.

Why can't I change the operating system of a simple application server?

Resetting the system lets you reinstall the server's application or operating system to reinitialize the server. If you cannot change the operating system of your simple application server in the Simple Application Server console, check whether the requirements for resetting the system are met. For more information, see Limits on resetting the system.

Does the mobile app support system reset?

Yes, it does, but the range of images available for reset differs from the range available in the console on a PC:

  • Console: Supports resetting to other images. You can change the server's operating system. For example, you can change from Windows to Linux or switch to a different application image.

  • Alibaba Cloud App: Supports only resetting to the current image. You can restore the server only to the initial state of the currently installed image. You cannot change to a different operating system or application image in the app.

How do I set the preferred language for a Windows operating system?

If the default language of the Windows operating system does not meet your needs, you can change the language within the operating system. For more information, see Set the preferred language for a Windows operating system.

How do I download an image of a simple application server?

Custom images of simple application servers cannot be downloaded directly. To download a custom image, follow these steps:

  1. Share the simple application server image with ECS. For more information, see Share an image to ECS.

  2. On the Shared Images tab in the ECS console, you can copy the image to create a custom image. For more information, see Copy a custom image.

  3. You can export the custom image from the Custom Images tab in the ECS console. For more information, see Export a custom image.

    Note

    Due to image copyright restrictions, you cannot export custom images created from application images or images of the Windows Server operating system.

What do I do if the initialization of a Plesk application image gets stuck at 95%?

  1. Enable the following firewall rules for the instance where the Plesk application image is located. For more information, see Firewall settings.

    • Enable TCP ports 80, 443, 8880, 8443, and 8447.

    • Enable UDP ports 443 and 8443.

  2. Use the root account to remotely connect to the instance where the Plesk application image is located. For more information, see Connect to a Linux server.

  3. Run the following command to update the configuration parameters.

    /usr/local/psa/bin/cloning --update -prepare-public-image true -reset-init-conf false -reset-license true -skip-update true
  4. Run the following command to restart the instance.

    reboot
  5. Re-initialize the Plesk application image by following the prompts on the console interface.

For more information about Plesk images, see the official Plesk documentation.

Can I migrate data between simple application servers?

Yes, you can. If a simple application server cannot meet your current business needs through configuration upgrades, or if you want to migrate the server to another region, you can migrate the website data from the server to another server in the same or a different region. For more information, see Migrate data between simple application servers.

Can I migrate a simple application server to an ECS instance?

Yes, you can. If your current simple application server cannot meet your business needs, you can migrate it to an Elastic Compute Service (ECS) instance to obtain more flexible resource configuration solutions. For more information, see Migrate data from a simple application server to an ECS instance.

Can a simple application server in the China (Hong Kong) region be moved to the Chinese mainland?

Yes, it can. After a simple application server is created, you cannot directly change its region, but you can migrate the server to the Chinese mainland. For more information, see Migrate data between simple application servers.

Can I transfer a simple application server to another Alibaba Cloud account?

No, you cannot. You cannot directly transfer a simple application server and its data to another Alibaba Cloud account.

How do I find common commands for application software management?

Application software management commands vary depending on the operating system, runtime environment, and software version. For example, in CentOS 7:

  • If MySQL has been added to the system services, the command to log on to MySQL is mysql -uroot -p.

  • If MySQL has not been added to the system services, you must go to the bin directory of the MySQL installation path and manage MySQL using the executable file. For example, the command to log on to MySQL is ./mysql -uroot -p.

Therefore, to maintain the application software on your server, we recommend that you first obtain the relevant operations and maintenance (O&M) knowledge from the official website of the software or other third-party websites. The official documentation for common application software is as follows:

If you selected an application image when you created the simple application server, you can obtain the image version, basic operation steps for the application, and installation path from the console after the server is created. For more information, see Manage applications (for application images).

How do I handle abnormal CPU usage caused by mining programs?

For more information, see Best practices for handling mining programs.

We also recommend that you perform security compliance checks and hardening on your Linux server. For more information, see Operating system security.

Why is the server unable to access GitHub?

When you access GitHub from a server that is deployed in the Chinese mainland, you may be unable to access it because of cross-border network issues. We recommend that you try again later or resolve the issue yourself using third-party tools.

What do I do if the "The following signatures were invalid: KEYEXPIRED 1544811256" error occurs on an Ubuntu server?

When you run the apt-get update command on an Ubuntu server, you may receive the The following signatures were invalid: KEYEXPIRED 1544811256 error. This error occurs because the signature of the software source used on the server has expired and needs to be updated. For more information, see What do I do if the "The following signatures were invalid: KEYEXPIRED 1544811256" error is reported when I run the apt-get update command?.

What do I do if "Internet Explorer Enhanced Security Configuration is blocking content from the following website" is reported when I use Internet Explorer to open a website in Windows?

For the solution, see Error "Internet Explorer Enhanced Security Configuration is blocking content from the following website" when opening a website with IE browser.

What are the database configuration file paths for common third-party open source programs?

The specific configuration file paths depend on the third-party open source program and the type of database used.

Important
  • If you perform risky operations such as modifying the instance or data, check the disaster recovery and fault tolerance capabilities of the instance to ensure data security.

  • If you modify the configuration and data of an instance (such as ECS or RDS), create a snapshot or enable RDS log backup in advance.

  • If you have authorized or submitted logon credentials or other security information on the Alibaba Cloud platform, change them promptly.

The following table lists the configuration file paths for PHP to call MySQL:

Software name

Configuration file path

UCenter

/data/config.inc.php

Discuz!

/config.inc.php

UCH

/config.php

EmpireCMS

/e/class/config.php

ECShop

/data/config.php

ShopEX

/config/config.php

WordPress

/wp-config.php

Joomla!

/configuration.php

HDWiki

/config.php

PHPwind 8.0

/data/sql_config.php

DedeCMS

/data/common.inc.php

PHPCMS

/include/config.inc.php

.NET program

/web.config

How do I resolve issues where features such as HTTPS settings, load balancing, system reset, and remote connection are affected after Cloud Assistant Agent is uninstalled or stopped?

Cloud Assistant Agent is installed on simple application servers by default. If you uninstall or stop Cloud Assistant Agent, features such as HTTPS settings, load balancing, system reset, and remote connection may be affected. Do not manually uninstall or stop Cloud Assistant Agent on your simple application server.

The solution is as follows:

  1. Remotely log on to the simple application server. For more information, see Connect to a Linux server or Connect to a Windows server.

  2. Check if the process that corresponds to Cloud Assistant Agent is running normally.

    • Linux server: Run the following command.

      ps -ef |grep aliyun-service

      If a response similar to the following is returned, the process that corresponds to Cloud Assistant Agent is running normally.

      root     30758 30703  0 16:38 pts/0    00:00:00 grep --color=auto aliyun-service
      root     31161     1  0  2021 ?        00:34:31 /usr/local/share/aliyun-assist/2.2.3.256/aliyun-service
    • Windows server: In Task Manager, check if the aliyun_assist_service process exists.

  3. If the process does not exist, start Cloud Assistant Agent.

    • Linux server: Run the following command.

      #For Linux systems that support systemctl
      systemctl start aliyun.service
      
      #For Linux systems that do not support systemctl
      /etc/init.d/aliyun-service start
    • Windows server: Start the AliyunService service in Service Manager.

Note

If you still cannot start Cloud Assistant Agent after you perform the preceding operations, reinstall Cloud Assistant. For more information, see Install Cloud Assistant Agent.

How do I configure multi-user logon for a Windows server?

By configuring multi-user logon, you can allow multiple users to remotely log on to the same simple application server at the same time. For more information, see Configure multiple concurrent remote desktop connections for Windows.

How do I upload files to a simple application server?

You can use WinSCP and FTP to upload files to a simple application server and perform operations such as uploading, downloading, creating, or deleting files. Select the appropriate method based on the server's operating system.

How do I install an application or software on a simple application server

If you are using a simple application server with an application image, the software or runtime environment is already installed. If you are not using a simple application server with an application image, you can remotely log on to the server to install an application or software yourself.

This example shows how to install Python:

  1. Remotely connect to the simple application server. For more information, see Connect to a Linux instance.

  2. Run the following command to install the Python environment.

    This example installs the Python 2.7 environment.

    sudo yum install python

    The system displays a response similar to the following. Enter y when prompted.

    Loaded plugins: fastestmirror 
    ... 
    Is this ok [y/d/N]: y
     ...
  3. Run the following command to check if the Python environment is installed successfully.

    python -V

    If the following response is returned, Python 2.7 has been installed successfully.

    [admin@iZbp176xsi6ct73elzq**** ~]$ python -V
    Python 2.7.5

How many service identification numbers does a simple application server support for ICP filings?

A simple application server supports up to five service identification numbers (SNs), which allow you to complete five website ICP filings. Each website can be associated with multiple domain names. For example, you have filed for two websites. The first website is associated with the domain name aliyundoc.com, and the second website is associated with the domain names example.com and example.org. After the ICP filing is approved, you can use each associated domain name to access the website.

Note
  • If the second website is associated with multiple domain names, you must ensure that these domain names open the same website content. You cannot use example.org to point to another website after the ICP filing is approved.

  • ICP filings are only for top-level domain names. You can build a new website on a simple application server and associate it with blog.aliyundoc.com, and then build another website and associate it with new.example1.com. This method of building websites is not restricted and does not count towards the limit of filing for a maximum of five websites.

What do I need to know before I apply for an ICP filing for a simple application server?

  • Before you use a simple application server in the Chinese mainland region to provide external website services, you need to apply for an ICP filing. For more information, see What is an ICP filing?

  • Simple application servers in regions outside the Chinese mainland do not require an ICP filing.

  • For more information about the ICP filing process, see ICP filing process.

  • A service identification number is a verification code used to associate your simple application server when you submit ICP filing information in the Alibaba Cloud ICP Filing system. For information about how to apply for a service identification number, see (Optional) Authorize another account for ICP filing. Note the following when you apply for a service identification number:

    • Starting from May 21, 2018, the subscription duration of a simple application server for which a service identification number is requested must be three months or longer (including renewals).

    • The public IP address of a server can be associated with up to five service identification numbers, which lets you complete five website ICP filings. A successful ICP filing for one website consumes one service identification number. The consumed service identification number is considered used and cannot be used for another website's ICP filing. If you later unregister the website or remove Alibaba Cloud from the service provider list, the service identification number remains in a used state and cannot be used for another website's ICP filing.

    • The number of domain names that can be submitted for each service identification number is as follows:

      • If it is your first ICP filing, you can submit five separate websites, and each website can correspond to multiple domain names.

      • If it is a new ICP filing, you need to submit only one domain name for each website, and you can submit multiple websites multiple times. For example, if multiple domain names are under the ICP filing number ICP Bei No. 1200000-1, you can add any one of the domain names under ICP Bei No. 1200000-1, and the other domain names are automatically added. After ICP Bei No. 1200000-1 is submitted, you can continue to submit other ICP filing numbers.

    • Domain names without an ICP filing cannot be used to launch a website for access in advance. You must shut down the website to apply for an ICP filing in accordance with relevant regulations.

    • If the website's domain name has already been successfully filed through other channels, you must transfer the ICP filing to Alibaba Cloud. After the ICP filing transfer request is approved by the system, the website can be opened for access. In addition, you must complete the transfer procedure within 30 days. Otherwise, the page will become inaccessible.

What is the ICP filing policy for simple application servers?

Starting from May 21, 2018, the subscription duration of your purchased simple application server must be three months or longer (including the cumulative duration of multiple renewals) to be eligible to apply for a service identification number. Other rules remain unchanged.

Simple application servers purchased before May 21, 2018, are still subject to the original service identification number application rules and are not affected by this adjustment.

I purchased a one-month simple application server and then renewed it for two months. Can I apply for a service identification number for an ICP filing?

Yes, you can. After you renew the server for two more months, your subscription duration reaches three months, and you can apply for a service identification number for an ICP filing.

I purchased a simple application server for more than three months, but it is about to expire. Can I still apply for a service identification number for an ICP filing?

Yes, you can. If the server's subscription duration is three months or longer, you can apply for a service identification number before it expires.

Important

During or after the ICP filing process, if the simple application server is not renewed and is released upon expiration, the successfully filed website can no longer point to that server. The ICP filing number may be canceled, and website access is affected.