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 (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 the RebootInstance operation. 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 (Pending) or Starting (Starting) state. Otherwise, the hostname and /etc/hosts configuration may not take effect. You can call the DescribeInstances operation 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 the RebootInstance operation. 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 (-), contain consecutive hyphens (-), or contain only digits.

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

The name of the instance. The name must be 2 to 128 characters in length. It must start with a letter 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 limits on 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 Overview of burstable instances.

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

The number of queues for the primary Elastic Network Interface (ENI). Take note of the following items:

• The instance must be in the Stopped (Stopped) state.

• The value cannot exceed the maximum number of queues per network interface controller (NIC) allowed by the instance type. The total number of queues for all NICs on the instance cannot exceed the queue quota allowed by the instance type. You can call the DescribeInstanceTypes operation 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 ENI is reset to the default value for the instance type. You can call the DescribeInstanceTypes operation to query the default number of queues per ENI 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 (Running) or Stopped (Stopped) state.

• The instance must be a VPC-connected instance.

• After the Jumbo Frame feature is enabled, the MTU value of the instance is changed to 8500. After the feature is disabled, the MTU value is reverted 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.

Default value: see Customize CPU options.

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.

For the valid values and default value, see Customize CPU options.

The CPU topology type of the instance. Valid values:

• ContinuousCoreToHTMapping: The hyper-threads (HTs) within the same core of the instance CPU topology are continuous.

• DiscreteCoreToHTMapping: The HTs within the same core are discrete.

Default value: none.

Take note of the following items:

• The instance must be in the Stopped (Stopped) state.

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

• true: enables the encryption.

• false: disables the encryption.