What Is AS?

Auto Scaling (AS) automatically adjusts resources to keep up with changes in demand based on pre-configured AS policies. This allows your applications to maintain steady, predictable performance at optimal costs while also freeing you from the cumbersome task of repeatedly, manually adjusting resources to respond to changes. AS automatically adjusts ECS and bandwidth resources.

Architecture

AS allows you to adjust the number of ECSs in an AS group and EIP bandwidth.

Scaling control: You can configure AS policies and set metric thresholds and the execution time of scaling actions. AS will trigger scaling actions when monitoring metrics reach the thresholds or the specified time or period arrives.
Policy configuration: You can configure alarm, scheduled, and periodic policies based on service requirements.
Alarm: You can set a alarm monitoring metric such as vCPU, memory, disk, and inbound traffic.
Scheduled: You can set a scheduled policy by configuring the triggering time.
Periodic: You can set a periodic policy by configuring the interval, triggering time, and time range.
When Cloud Eye generates an alarm for a monitoring metric, such as CPU usage, AS automatically increases or decreases the number of instances in the AS group or the EIP bandwidth.
When the configured triggering time arrives, a scaling action is triggered to increase or decrease the number of ECS instances or the bandwidth.

Figure 1 AS architecture

How to Access

The public cloud provides a web-based service management platform. You can access ECSs through HTTPS-compliant application programming interfaces (APIs) or the management console.

Calling APIs
Use this method if you are required to integrate the AS service on the public cloud platform into a third-party system for secondary development. For detailed operations, see Auto Scaling API Reference.
Management console
Use this mode if you are not required to integrate the AS service with a third-party system.

After registering on the public cloud platform, log in to the management console and click Auto Scaling under Computing on the homepage.