# Amazon EC2 Auto Scaling in Amazon Web Services in China
<a name="ec2-auto-scaling"></a>

 Amazon EC2 Auto Scaling allows you to scale your Amazon EC2 capacity up or down automatically according to conditions you define. With Amazon EC2 Auto Scaling, you can ensure that the number of Amazon EC2 instances you’re using increases seamlessly to maintain performance during demand spikes, and decreases automatically to minimize costs during demand lulls. Amazon EC2 Auto Scaling is particularly well suited for applications that experience hourly, daily, or weekly variability in usage. Amazon EC2 Auto Scaling is enabled by Amazon CloudWatch and available at no additional charge beyond CloudWatch fees.

For information about related services, see:
+  [Amazon Auto Scaling](https://docs.amazonaws.cn/aws/latest/userguide/auto-scaling.html) 
+  [Application Auto Scaling](https://docs.amazonaws.cn/aws/latest/userguide/application-auto-scaling.html) 

## Region availability
<a name="feature-regions"></a>

 Amazon EC2 Auto Scaling is available in the following regions in China:
+ Beijing Region
+ Ningxia Region

## How Amazon EC2 Auto Scaling differs
<a name="feature-diff"></a>

The following differences apply to Amazon EC2 Auto Scaling:
+  Amazon EC2 provides certain restrictions. For more information, see [Amazon Elastic Compute Cloud](https://docs.amazonaws.cn/aws/latest/userguide/ec2.html).
+  `Hibernated` is not available as a pool state when creating or updating a warm pool.
+ Specifying the `NetworkBandwidthGbps` attribute for an Auto Scaling group that uses attribute-based instance type selection is not available in the Beijing and Ningxia Regions.
+ Specifying the `AllowedInstanceTypes` attribute for an Auto Scaling group that uses attribute-based instance type selection is not available in the Beijing and Ningxia Regions.
+ Predictive scaling recommendations feature is not currently available in the Beijing and Ningxia Regions.

## Documentation
<a name="feature-guides"></a>

Amazon Web Services in China user guides are available in HTML and PDF, in both Chinese and English. API references are available in HTML and PDF. Some API references may be available only in English. Currently, not all API references are available in the Beijing and Ningxia Regions. Links to some API references will take you to the global Amazon Web Services site. Note that some features and functionality described in the guides and references may not be available in the current Amazon Web Services in China release.
+  [Amazon EC2 Auto Scaling User Guide](https://docs.amazonaws.cn/autoscaling/ec2/userguide/) 
+  [Amazon EC2 Auto Scaling API Reference](https://docs.amazonaws.cn/autoscaling/ec2/APIReference/) 

## General Information About Amazon Web Services in China
<a name="general-info"></a>

The following information applies to all Amazon Web Services that are available in the China Regions.

 **Amazon Web Services Accounts in the China Regions** 

To use services in the Beijing and Ningxia Regions, you need an account and credentials specific to each of those Regions.
+ Accounts and credentials for other Amazon Regions will not work for services operating in the Beijing and Ningxia Regions.
+ Accounts and credentials for the Beijing and Ningxia Regions will not work for other Amazon Regions.
+ For more information, see [Signup, Accounts, and Credentials](accounts-and-credentials.md).

 **Domain for Amazon Web Services in China** 

The domain for Amazon Web Services in China is **www.amazonaws.cn**.

 **Endpoints & Amazon Resource Names (ARNs)** 

For information about endpoints and ARNs in Amazon Web Services in China, see [Endpoints and ARNs for Amazon Web Services in China](endpoints-arns.md).

 ** Availability Zones for the China Regions** 
+ In the Beijing Region, there are three Availability Zones.
+ In the Ningxia Region, there are three Availability Zones.

 **General Information for Amazon Web Services in China** 

The following applies to all Amazon Web Services that are available in the China Regions. For detailed information about specific Amazon Web Services, see the service-specific topic in this guide.
+ Amazon Identity and Access Management (IAM)
  + You can grant or deny a service access to resources using the `Principal` policy element.
  + Service principal values vary by Region.
+ Free Usage Tier
  + For information about Free Tier offers and availability in the China Regions, see [Amazon Web Services China Regions Free Tier](https://www.amazonaws.cn/en/free).

 **Amazon Web Services Console** 

The console for Amazon Web Services in China is unique to China. The screenshots in the Amazon Web Services guides might differ from what you see on your console. For information about differences in service functionality, see the topics for each service in this guide.

 **Code Examples** 

The Amazon Web Services documentation might include endpoints and ARNs in code examples that are not specific to the Beijing and Ningxia Regions. When using examples, verify you are using the endpoints and ARNs for your Region.