This topic describes how to configure sequential names or hostnames for multiple instances when you create instances in a batch in the ECS console or via OpenAPI. This helps you to better manage your instances.

Configuration rules

Naming rules

The naming rules for instance names and hostnames are listed below:

Type	Naming rules
Instance name	Start with a letter or a Chinese character. Only Chinese characters, letters, digits, underscores (_), hyphens (-), and dots (.) are allowed. It must be 1 to 128 characters in length.
Host name	Linux instances: Letters, numbers, periods ".", and hyphens "-" are allowed. Can not start or end with a hyphen or period. Hyphens and periods can not be used consecutively. The length limit is 2 to 63 characters. Windows instances: Letters, numbers, and hyphens ("-") are allowed, but the name cannot consist only of digits. Can not start or end with a hyphen. Hyphens can not be used consecutively. The length limit is 2 to 15 characters.

Naming format

Format

Parameter format of configuring sequential names: name_prefix[begin_number,bits]name_suffix. Detailed field descriptions are listed below.

Field	Description	Examples
name_prefix	Indicates the prefix of instance names or hostnames. You are required to specify this field based on the naming rules.	name
[begin_number,bits]	begin_number: Specifies the starting number of instance names or hostnames. Value range: [0,9999] Default value: 0 bits: Specifies the number of bits that value(s) occupy in instance names or hostnames. Value range: [1,4] Default value: 4 tip Only English commas (,) are supported to separate values of "begin_number" and "bits", and no spaces are allowed between. If [begin_number,bits] is specified as [] or [,], the value of "begin_number" starts from 0, and "bits" takes the default value 4. If the total digits of begin_number plus Count (instance number) exceed the specified bits, the names are created based on the actual total digit count. This total cannot exceed the maximum allowed bits. Otherwise, the creation fails.	[99,3]
name_suffix	Indicates the suffix of instance names or hostnames.	ecs

Examples

Description	Input parameter	Instance names (three instances)
Standard format	name[1,3]ecs	name001ecs, name002ecs, name003ecs
Standard format. Digits of begin_number + Count: > specified value of "bits"	name[99,2]ecs	name099ecs, name100ecs, name101ecs
"begin_number" and "bits" are left empty	name[]ecs or name[,]ecs	name0000ecs, name0001ecs, name0002ecs

Procedure

ECS console

OpenAPI

The following mainly describes how to configure instance names and hostnames. For more instance configurations, refer to Purchasing an instance by following the wizard.

Log in to the ECS console.

Click the "Create instance" button to purchase an ECS instance.

Configure the information in Basic configuration and Network configuration.

On the "Custom configuration" tab, in the "Instance name" (required) or "Hostname" field, enter the desired sequence in the format name_prefix[begin_number,bits]name_suffix. For configuration rules, see Naming format. Then complete the remaining configurations.

In the example provided in this topic, name[1,3]ecs is entered in "Instance name", and name[1,3]host in "Hostname".

Set the number of instances to 3 to complete the purchase.

Operation results:

After the purchase, you can view the three newly created instances on the Instances page. Their sequential instance names are name001ecs, name002ecs, and name003ecs, and sequential hostnames are name001host, name002host, and name003host.

When you create instances in a batch by calling the RunInstances interface, the sequential suffix parameter UniqueSuffix can affect the sequential names of instances. Details are as follows.

tip

The following mainly introduces arguments for configuring sequential names. For information about other arguments, refer to RunInstances.

To configure sequential names for parameters InstanceName and Hostname, specify the parameters in the format name_prefix[begin_number,bits]name_suffix. For configuration rules, refer to Naming format.

Disable sequential suffix feature, with [begin_number,bits] specified only

Enable sequential suffix feature, with [begin_number,bits] not specified

Enable sequential suffix feature, with [begin_number,bits] specified

After disabling the sequential suffix feature (disabled by default), you can sequence names of the instances created in a batch by specifying values in the format of [begin_number,bits]. Detailed argument configurations are as follows:

UniqueSuffix: false (default). This means not adding sequential suffixes for specified values of InstanceName and Hostname.

Count: 3

InstanceName: name[1,3]ecs

Hostname: name[1,3]host

Based on the operations above, the sequential names of the three newly created instances are name001ecs, name002ecs, and name003ecs. Their sequential hostnames are name001host, name002host, and name003host.

Enabled sequential suffix feature	Whether InstanceName/Hostname specified in format [begin_number,bits]	Whether UniqueSuffix is valid	Examples
UniqueSuffix=true, and SuffixIndex takes the default value 1	Both specified	Invalid for both parameters	Specify InstanceName and Hostname as name[666,3]ecs Final generated names: The instance names and hostnames are the same: name666ecs, name667ecs, name668ecs
		Specify InstanceName, not Hostname	Valid for Hostname	Specify InstanceName as name[666,3]ecs and Hostname as host Final generated names: Instance names: name666cs, name667ecs, and name668ecs Hostnames: host-1, host-2, and host-3
		Specify Hostname, not InstanceName	Valid for InstanceName	Specify InstanceName as ecs and Hostname as name[666,3]host Final generated names: Instance names: ecs-1, ecs-2, and ecs-3 Hostnames: name666host, name667host, and name668host

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