Elastic Compute Service:ModifyInstanceAttribute

The ID of the instance.

The password of the instance. The password must be 8 to 30 characters long and contain at least three of the following character types: uppercase letters, lowercase letters, digits, and special characters. The supported special characters are ()~!@#$%^&*-_+=|{}[]:;'<>,.?/. For a Windows instance, the password cannot start with a forward slash (/). Note the following when you use this parameter:

• The instance cannot be in the Starting state.

• The new password takes effect after you restart the instance from the ECS console (see Restart an instance) or by calling the RebootInstance operation. Restarting the instance from within its operating system does not apply the change.

The hostname of the operating system. Note the following when you use this parameter:

• The instance cannot be in the Pending or Starting state. Otherwise, the specified hostname and the /etc/hosts configuration may not take effect. You can call the DescribeInstances operation to query the current state of the instance.

• The new hostname takes effect after you restart the instance from the ECS console (see Restart an instance) or by calling the RebootInstance operation. Restarting the instance from within its operating system does not apply the change.

The hostname must meet the following requirements for different operating systems:

• For Windows Server instances: The hostname must be 2 to 15 characters long and contain letters, digits, and hyphens (-). It cannot start or end with a hyphen, contain consecutive hyphens, or consist of only digits.

• For other types of instances (such as Linux): The hostname must be 2 to 64 characters long. You can use periods (.) to separate the hostname into segments. Each segment can contain letters, digits, and hyphens (-). The hostname cannot start or end with a period or hyphen, and cannot contain consecutive periods or hyphens.

The instance name. The name must be 2 to 128 characters long. It must start with a letter or a Chinese character and cannot start with http:// or https://. The name can contain digits, colons (:), underscores (_), and hyphens (-).

The instance description. The description must be 2 to 256 characters long and cannot start with http:// or https://.

The user data of the instance. User data should be Base64-encoded before it is passed. Note the following when you use this parameter:

• The user data must comply with the limits described in Generate user data.

• After you restart the instance, the new user data is available on the instance but is not executed.

The performance mode of the burstable performance instance. Valid values:

• Standard: standard mode.

• Unlimited: unlimited mode.

For more information about the performance modes of burstable performance instances, see Overview of burstable performance instances.

Specifies whether to enable deletion protection for the instance. This setting prevents the instance from being released from the console or by calling the DeleteInstance operation.

The number of queues for the primary network interface. Note the following when you use this parameter:

• The instance must be in the Stopped state.

• The value cannot exceed the maximum number of queues that the instance type supports for a single network interface. The total number of queues across all network interfaces of the instance cannot exceed the total queue quota that the instance type supports. You can call the DescribeInstanceTypes operation to query the maximum number of queues per network interface and the total queue quota for an instance type.

• If you set this parameter to -1, the number of queues for the primary network interface is reset to the default value for the instance type. You can call the DescribeInstanceTypes operation to query the default number of queues for an elastic network interface of an instance type.

Specifies whether to enable jumbo frames. When jumbo frames are enabled, the MTU of the instance is 8500. When jumbo frames are disabled, the MTU of the instance is 1500. Valid values:

• true

• false

Note the following when you use this parameter:

• The instance must be in the Running or Stopped state.

• The instance must be in a VPC.

• Only some instance types support jumbo frames. For more information, see ECS instance MTU.

The number of CPU cores. This parameter is not customizable and uses a default value.

The number of threads per core. The total number of vCPUs for an ECS instance is the value of CpuOptions.Core multiplied by the value of CpuOptions.ThreadsPerCore.

• Setting CpuOptions.ThreadsPerCore to 1 disables hyper-threading.

• Only some instance types support specifying the number of threads per core.

The CPU topology type of the instance. Valid values:

• ContinuousCoreToHTMapping: The hyper-threads of the same core are contiguous.

• DiscreteCoreToHTMapping: The hyper-threads of the same core are discrete.

Default value: None.

Note the following when you use this parameter:

• The instance must be in the Stopped state.

Specifies whether to enable VPC network traffic encryption. Valid values:

• true

• false