Creating an AS Configuration from a New Specifications Template

Scenarios

If you have special requirements on the ECS instances for resource expansion, use a new specifications template to create the AS configuration. In such a case, ECS instances that have the specifications specified in the template will be added to the AS group in scaling actions.

Procedure

1. Log in to the management console.
2. Under Compute, click Auto Scaling. In the navigation pane on the left, choose Instance Scaling.
3. Click Create AS Configuration.
4. Set the parameters for the AS configuration. Table 1 lists the AS configuration parameters.

   Table 1 AS configuration parameters

   Parameter	Description	Example Value
   Region	A region is where an AS configuration resides.	N/A
   Name	Specifies the name of the AS configuration to be created.	N/A
   Configuration Template	Select Create new template. If this option is selected, configure parameters, such as the vCPUs, memory, image, disk, and ECS type, to create a new AS configuration.	Create new template
   CPU Architecture	Both x86 and Kunpeng CPU architectures are available: x86: The x86-based CPU architecture uses Complex Instruction Set Computing (CISC). Kunpeng: The Kunpeng-based CPU architecture uses Reduced Instruction Set Computing (RISC). NOTE: This parameter is displayed only when both x86-based and Kunpeng-based ECSs are available in the current region.	x86
   Specifications	The public cloud provides various ECS types for different application scenarios. For more information, see Elastic Cloud Server User Guide. Configure the ECS specifications, including vCPUs, memory, image type, and disk, according to the ECS type.	Memory-optimized ECS
   Image	Public image A public image is a standard, widely used image. It contains an OS and preinstalled public applications and is available to all users. You can configure the applications or software in the public image as needed. Private image A private image is an image available only to the user who created it. It contains an OS, preinstalled public applications, and the user's private applications. Using a private image to create ECSs frees you from configuring multiple ECSs repeatedly. Shared image A shared image is a private image shared by another public cloud user.	Public image
   Disk	Includes system and data disks. System Disk Common I/O: uses Serial Advanced Technology Attachment (SATA) drives to store data. High I/O: uses serial attached SCSI (SAS) drives to store data. General Purpose SSD: uses solid state disk (SSD) drives to store data. Extreme SSD: uses enhanced solid state disk (ESSD) drives to store data. Ultra-high I/O: uses solid state disk (SSD) drives to store data. If a full-ECS image is used, the system disk is restored using the disk backup. On the console, you can only change the volume type and size. In addition, the volume cannot be smaller than the disk backup. NOTE: Different ECS flavors support different disk types. The supported disk types will be displayed on the management console. Data Disk You can create multiple data disks for an ECS instance. In addition, you can specify a data disk image for exporting data. If the image you selected is a full-ECS image, you can change the volume type and size and encryption attributes of the data disk restored using the disk backup. Ensure that the disk is at least as big as the disk backup. The encryption attributes can only be modified if the disk backup is in the same region as the disk.	Common I/O for System Disk
   Security Group	Controls ECS access within or between security groups by defining access rules. ECSs added to a security group are protected by the access rules you define.	N/A
   EIP	An EIP is a static public IP address bound to an ECS in a VPC. Using the EIP, the ECS provides services externally. The following options are provided: Do not use: An ECS without an EIP cannot access the Internet. However, it can still be used as a service ECS or deployed in a cluster on a private network. Automatically assign: An EIP with a dedicated bandwidth is automatically assigned to each ECS. You can set the bandwidth size. If you select Automatically assign, you need to specify EIP Type, Billed By, and Bandwidth. NOTE: If you select Automatically assign, you need to specify EIP Type, Billed By, and Bandwidth.	Automatically assign
   Bandwidth	Specifies the bandwidth size in Mbit/s. NOTE: This parameter is available only when EIP is set to Automatically assign. If you select Dedicated, you can select Bandwidth or Traffic for Billed By. The shared bandwidth can be billed only by bandwidth. You can select a shared bandwidth to which the EIP is to be added.	100
   Login Mode	An ECS can be authorized using a key pair or a password. Key pair Keys are used for authenticating the users who attempt to log in to ECS instances. If you select this mode, create or import a key pair on the Key Pair page. NOTE: If you use an existing key, make sure that you have saved the key file locally. Password The initial password of user root (for Linux) or user Administrator (for Windows) is used for authentication. You can log in to an ECS instance using a username and password combination.	Admin@123
   Advanced Settings	This parameter allows you to configure ECS Group, and User Data. You can select Do not configure or Configure now.	N/A
   User Data	Enables an ECS to automatically inject user data when the ECS starts for the first time. This configuration is optional. After this function is enabled, the ECS automatically injects user data during its first startup. For details, see Elastic Cloud Server User Guide. The following methods are available: As text: allows you to enter the user data in the text box below. As file: allows you to inject script files or other files when you create an ECS. NOTE: For Linux, if you use password authentication, this function is not supported. If the selected image does not support user data injection, this function is not supported.	N/A
   ECS Group	An ECS group allows you to create ECSs on different hosts to improve service reliability.	N/A

5. Click Create Now. The system displays a message indicating that the AS configuration is successfully created.
6. If you want to use the newly created AS configuration, add it to the AS group. For details, see Creating an AS Group or Changing the AS Configuration for an AS Group.

Notes on Multiple Flavors in an AS Configuration

AS configuration supports multiple flavors to minimize the probability of capacity expansion failures due to insufficient or unavailable flavors and ensure that capacity expansion succeeds during peak hours.

Applicable Scenario

• No special requirement for the instance flavors created in the AS group
• Requiring higher success ratio and low latency of creating instances in an AS group
• Requiring instances with high specifications
• Services that are stateless and can be horizontally scaled

The AS group sorts multiple flavors in either of the following ways:

• Sequenced: During AS group expansion, flavors are used based on the sequence they are selected. When the first flavor is insufficient or the instance fails to be created due to other reasons, the system attempts to create an instance of the second flavor, and so on.
• Cost-centered: During AS group expansion, the flavor with the minimum cost comes first. When creating an instance in an AS group, the system selects the flavor with the minimum cost. If the instance cannot be created, the system selects one with the minimum cost from the remained flavors, and so on.