Elastic Compute Service:Instance management and O&M FAQ

Upgrading a subscription instance

Yes. For more information, see Change the instance type of a subscription instance.

Upgrading a pay-as-you-go instance

Yes, but you must stop the instance first. For more information, see Change the instance type of a pay-as-you-go instance or call the ModifyInstanceSpec API operation to upgrade the configurations of a pay-as-you-go instance.

Upgrade duration

• Upgrading the instance type of a subscription instance takes about 15 minutes and does not require you to stop the instance.

• Upgrading the instance type of a pay-as-you-go instance requires you to stop the instance and takes about 15 minutes.

• Upgrading the bandwidth of an instance does not require you to stop the instance and takes about 5 minutes.

Upgrade fees

When you upgrade the instance type and configuration of an ECS instance, the fees are displayed on the page. You can also go to the Billing Management console to view the fee details.

Service impact from upgrades

Upgrading a pay-as-you-go instance requires you to stop it, while upgrading a subscription instance requires a restart for the new configuration to take effect. The upgrade operation causes a brief service interruption. We recommend that you perform upgrades during off-peak hours. After the upgrade, the instance seamlessly integrates with your services. You do not need to reconfigure the ECS environment.

Upgrading ECS resources

When upgrades do not take effect

For the new configuration to take effect, you must restart the instance through the console or by using an API operation.

Canceling upgrade orders

No. After an upgrade order takes effect, the configuration is upgraded, and the order cannot be canceled. To restore the original configuration, you must downgrade the instance. You will then be billed based on the new, downgraded configuration.

Exporting resource usage

You can download an intelligent water level analysis report from Enterprise Cloud Monitor to export resource information from the last month. If you are using Enterprise Cloud Monitor for the first time, you must activate it separately. Enterprise Cloud Monitor uses a pay-as-you-go billing method. Activating the service is free of charge, and you are subsequently charged based on your actual usage. For more information about billing, see Intelligent water level analysis.

Converting to a subscription instance

No.

Changing the instance type

No.

Upgrading an underpowered spot instance

Because you cannot change the instance type of a spot instance, we recommend that you create a custom image from the system disk of the spot instance. You can then use the custom image to create a spot instance with a larger instance type. For more information, see Create a custom image from a snapshot and Create an instance by using a custom image or a shared image.

Release with automatic bidding

Automatic bidding caps the price at the pay-as-you-go rate, which prevents release if the market price exceeds your bid. However, the instance can still be released if the inventory for the specified instance type is insufficient.

Release with maximum bid price

Setting the maximum price to the pay-as-you-go rate prevents the instance from being released due to market price fluctuations. However, the instance can still be released if the inventory for the specified instance type is insufficient.

Cancel or change a scheduled release

Yes. You can cancel or change the release time at any point before the spot instance is released.

Unexplained instance release

After the protection period of a spot instance ends, the instance is reclaimed if the market price exceeds your bid or if the supply of ECS resources changes.

Release rate calculation

The release rate is calculated based on the availability zone and instance type. The daily release rate is calculated by using the following formula: Daily release rate = Total number of released instances in a day / Total number of active instances in a day. A release rate between 0% and 3% is expected. Alibaba Cloud continuously works to lower the release rate so that you can use spot instances more reliably.

Release notifications

Yes. When a spot instance is scheduled for release due to market price changes or supply and demand adjustments, it first enters a pending-release state and is then automatically released approximately 5 minutes later.

To receive notifications, subscribe to spot instance interruption notifications in CloudMonitor. For more information, see Configure event-triggered alert rules.

To confirm whether an instance is in a pending-release state, you can query its instance metadata or the OperationLocks information returned by the DescribeInstances operation. For more information, see Instance metadata and DescribeInstances.

Data retention after release

No. If you temporarily do not need a spot instance, we recommend that you create a snapshot to back up your data and environment, and then release the instance. You can then purchase a new spot instance when needed. For more information, see Create a snapshot for a disk.

Startup failure in economical mode

After you enable economical mode, the instance may fail to start if the resource inventory is insufficient. To save the business data in the instance, follow these steps:

1. Create a snapshot of the cloud disk for the instance (Instance A). For more information, see Create a snapshot for a disk.

   The snapshot is complete once the creation progress reaches 100%.

2. Create a custom image from the snapshot. For more information, see Create a custom image from a snapshot.

   The custom image is ready for use when its status changes to Available.

3. Use the custom image to create another instance (Instance B).

   For more information, see Create an instance by using a custom image or a shared image.

4. Check whether the business data in Instance B is intact.

   • If the business data is intact, you can release Instance A. For more information, see Release an instance.

   • If the business data is corrupted, detach the cloud disk from Instance A, ensuring you deselect Release with instance when detaching. Then, attach it to Instance B and release Instance A. For more information, see Detach a data disk and Release an instance.

Release reversal

No, the spot instance will not be retained. After an instance receives a pending-release notification, it is marked for release. This state is irreversible, and the instance will be released on schedule.

Retaining a public IP address

When a spot instance is released, its public IP address is also reclaimed. If you need to use a specific public IP address, we recommend that you use an EIP.

You can convert an existing public IP address to an EIP. For more information, see Convert a public IP address of a VPC-type ECS instance to an EIP.

Cost-effectiveness

A spot instance with no protection period is always more cost-effective. It is approximately 10% cheaper than a spot instance with a protection period.

Release rate

Release priority

No.

Default protection period

Release notification

Yes. You receive the same notification as you would for a spot instance with a protection period, which provides you with time to handle the interruption.

Resource availability

There is no significant difference in the resource availability for the two types of spot instances.

Switching the protection period

No. By default, a spot instance has a 1-hour protection period. You can specify whether to have a protection period only when you create a spot instance. You cannot change this setting after the instance is created.

Symptom

After you install MySQL on an ECS instance, you can log on locally. However, when you try to connect to the MySQL database remotely by using the same username and password, the connection fails and the error message "1045 - Access denied for user 'root'@'****'(using password:YES)" is displayed. You have confirmed that you entered the correct username and password.

Cause

By default, after you install MySQL on an ECS instance, MySQL allows only local logons. The database does not permit remote connections from other IP addresses.

Solution

Grant remote logon permission to other IP addresses.

1. Connect to the ECS instance.

   For more information, see Connection methods.

2. Log on to the database and run the following SQL commands to grant remote logon permission to the MySQL database.

   Replace <user_name> and <password> with the username and password that caused the remote logon failure.

   CREATE USER '<user_name>'@'%' IDENTIFIED BY '<password>';
   GRANT ALL PRIVILEGES ON *.* TO '<user_name>'@'%' WITH GRANT OPTION;
   FLUSH PRIVILEGES;

   Note

   After running this command sequence, the user can log on to the database from any IP address and operate on any object in any database.Note: This command sequence is for MySQL 8.0 and later. MySQL 5.7 and earlier may support the original single GRANT command. For security reasons, do not allow access from any IP address (specified by %) in a production environment. We recommend that you: 1) restrict access to specific IP addresses, such as 'root'@'192.168.1.100'; 2) create a dedicated account for remote access; 3) set a strong password; and 4) avoid granting ALL PRIVILEGES.

   The following table describes the parameters in the SQL commands.

   Parameter	Description
   *.*	The first asterisk (*) is a placeholder for databases. If you enter *, it represents all databases. The second asterisk (*) is a placeholder for tables. If you enter *, it represents all tables in the specified databases.
   'root'@'%'	root is the database account for which you want to grant logon permissions, and the percent sign (%) is a placeholder for an IP address. To allow logons only from the IP address 1.1.1.1, replace % with 1.1.1.1. If you specify %, logons from any IP address are allowed.

3. Run the following SQL statement to refresh the permissions:

   flush privileges;

4. Try to remotely connect to the MySQL database again. If the error no longer appears, the issue is resolved.

Symptom

A remote connection to MySQL on a Linux ECS instance fails, and the error message "ERROR 2003 (HY000): Can't connect to MySQL server on '39.106.**.**' (110)" is displayed.

Cause

The remote connection to MySQL may fail because the IP address 39.106.**.** lacks permission to access MySQL, meaning port 3306 is not listening for connections from this IP address.

Solution

1. Log on to the Linux instance on which MySQL is installed.

   For more information, see Connect to a Linux instance by using a password or key.

2. Run the following command to back up the my.cnf file:

   cp /etc/my.cnf /etc/my.cnf.bak

3. Modify the my.cnf configuration file.

   1. Run the following command to open the my.cnf file:

      vim /etc/my.cnf

   2. Press the i key to enter edit mode, and add the following content to the my.cnf file.

      bind-address = 0.0.0.0

      Add the content as shown in the following figure.

      

   3. After you add the content, press the Esc key to exit Edit mode, enter :wq, and then press the Enter key to save the file and exit.

4. Run the following command to restart the MySQL service and verify that port 3306 is listening as expected:

   service mysqld restart

Upload files to a Linux instance

You can use an FTP service to upload files to a Linux instance.

Upload files from macOS by using FTP

Method 1: Use the built-in macOS terminal

You can upload files using the macOS terminal or iTerm2 (Download iTerm2). Make sure to specify the correct upload path.

1. Connect to the FTP service.

2. Navigate to the correct directory. This step is not required for Windows instances. For Linux instances, switch to the htdocs directory.

3. Run the put command to upload the file.

Method 2: Use a third-party tool

1. Download Yummy FTP.

2. Install Yummy FTP on macOS.

3. Enter the IP address, username, and password of the FTP server. For Protocol, select Standard (FTP). For Port, use the default port 21 or a custom port. Do not select an SSH key.

4. Click Connect.

5. In the right-side pane, select the destination directory. This step is not required for Windows instances. For Linux instances, select the htdocs directory. In the left-side pane, select the file to upload and click Upload.

   If the message "Your security preferences allow installation of only apps from the Mac App Store and identified developers" appears when you install Yummy FTP, perform the following steps:

   1. Go to System Preferences > Security & Privacy.

   2. Click the lock icon in the lower-left corner and enter the administrator password to unlock the settings.

   3. In the Allow apps downloaded from section, select Anywhere.

   After you configure the settings, you can install the software.

Linux system

Log on to the instance as the root user and run the following commands in order.

bash /usr/local/cloudmonitor/cloudmonitorCtl.sh stop
bash /usr/local/cloudmonitor/cloudmonitorCtl.sh uninstall
rm -rf /usr/local/cloudmonitor

Windows system

Log on to the instance as an administrator, open Command Prompt by pressing Win+R and entering cmd, and then run the following commands in order.

net stop argusagent
"C:\Program Files\Alibaba\cloudmonitor\bin\argusagent_service.exe" uninstall
cd C:\Program Files\Alibaba
rd /s /q cloudmonitor

Symptom

WeChat Official Accounts Platform token verification fails on an ECS instance.

Cause

Common causes for this issue include:

• Improper file editing, for example, with Notepad or an online editor, adds a UTF-8 byte-order mark (BOM) to the file.

• Security software such as Safedog or Security Center is installed on the ECS instance, which may block requests from Tencent servers.

• On a HiChina virtual host, using a temporary domain name for verification causes the system to block the request.

• The PHP file contains a newline or other characters after the closing tag.

• You are using a debugging method that does not accurately simulate WeChat API requests.

• The application encounters a Gzip encoding exception.

Solution

The following solutions correspond to the potential causes.

• Improper file editing, such as using Notepad or an online editor

  Use an advanced text editor to remove the BOM.

• The ECS instance has Safedog or Security Center installed

  Uninstall Safedog, or configure a whitelist in Security Center.

• Using a temporary domain name for verification on a virtual host

  Use a registered domain name that has a valid Alibaba Cloud ICP filing for verification.

• A PHP file contains a newline or other characters after the closing tag

  Remove the extra characters.

• Using an inaccurate debugging method

  To simulate a WeChat API request for debugging and analysis, run the curl http://xxx/index.php/api/xx command.

• Gzip encoding exception

  Temporarily disable the Gzip feature in your application.

Symptom

When you connect to a Linux ECS instance by using a third-party SSH client, Chinese characters appear as garbled text.

Cause

Possible causes for this issue include:

• The Chinese language pack is not installed on the Linux operating system, so the system cannot display Chinese characters. To fix this, see Method 1: Install the Chinese language pack.

• The character set is misconfigured in the third-party SSH client. To fix this, see Method 2: Modify character set settings in the SSH client.

Solution

Choose a method based on the cause.