Elastic Compute Service:ModifyInstanceAttribute

The instance ID.

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

• The instance cannot be in the Starting state.

• The new password takes effect after you restart the instance. You can restart the instance in the ECS console (for more information, see Restart an instance) or by calling RebootInstance. Restarting the instance from within the operating system does not take effect.

The hostname of the operating system. Take note of the following items:

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

• The new hostname takes effect after you restart the instance. You can restart the instance in the ECS console (for more information, see Restart an instance) or by calling RebootInstance. Restarting the instance from within the operating system does not take effect.

The hostname has the following limits for different operating systems:

• Windows Server: The hostname must be 2 to 15 characters in length and can contain uppercase letters, lowercase letters, digits, and hyphens (-). It cannot start or end with a hyphen (-), cannot contain consecutive hyphens (-), and cannot contain only digits.

• Other instances (such as Linux): The hostname must be 2 to 64 characters in length. You can use periods (.) to separate the hostname into multiple segments. Each segment can contain uppercase letters, lowercase letters, digits, and hyphens (-), but cannot contain consecutive periods (.) or hyphens (-). The hostname cannot start or end with a period (.) or hyphen (-).

The name of the instance. The name must be 2 to 128 characters in length. It must start with an uppercase letter, lowercase letter, or Chinese character and cannot start with http:// or https://. The name can contain digits, colons (:), underscores (_), and hyphens (-).

The description of the instance. The description must be 2 to 256 characters in length and cannot start with http:// or https://.

The instance user data. We recommend that you Base64-encode the data before you pass it in. Take note of the following items:

• The instance must meet the usage limits for instance user data. For more information, see Create instance user data.

• After you restart the instance, the new user data is displayed on the instance but is not run.

The running mode of the burstable instance. Valid values:

• Standard: standard mode.

• Unlimited: unlimited mode.

For more information about the running modes of burstable instances, see What are burstable instances?.

The release protection attribute of the instance. Specifies whether the instance can be released from the console or by calling DeleteInstance.

The number of queues for the primary network interface controller (NIC). Take note of the following items:

• The instance must be in the Stopped state.

• The value cannot exceed the maximum number of queues per NIC allowed by the instance type. The total number of queues for all NICs on the instance cannot exceed the total queue quota allowed by the instance type. You can call DescribeInstanceTypes to query the maximum number of queues per NIC and the total queue quota for an instance type.

• If you set this parameter to -1, the number of queues for the primary NIC is reset to the default value for the instance type. You can call DescribeInstanceTypes to query the default number of Elastic Network Interface (ENI) queues for an instance type.

Specifies whether to enable the Jumbo Frame feature for the instance MTU. Valid values:

• true: enables the feature.

• false: does not enable the feature.

Take note of the following items:

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

• The instance must be a VPC-connected instance.

• After the Jumbo Frame feature is enabled, the MTU value of the instance changes to 8500. After the feature is disabled, the MTU value reverts to 1500. Only some instance types support the Jumbo Frame feature. For more information, see ECS instance MTU.

The number of CPU cores. This parameter does not support custom values and can only use the default value.

The number of threads per CPU core. The number of vCPUs of the ECS instance = CpuOptions.Core value × CpuOptions.ThreadsPerCore value.

• CpuOptions.ThreadsPerCore=1 indicates that hyper-threading is disabled.

• Only some instance types support custom thread counts.

The CPU topology type of the instance. Valid values:

• ContinuousCoreToHTMapping: the hyper-threads of the same core in the CPU topology are continuous.

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

Default value: none.

Take note of the following items:

• The instance must be in the Stopped state.

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

• true: enables the encryption.

• false: disables the encryption.