Auto Scaling:Manually scale ECS instances with a few clicks

Scenario

Description

Solution

You can manually execute scaling rules to increase or decrease the number of servers.

Benefits

• No initial costs for resource setup

  Auto Scaling creates and releases ECS instances based on your business requirements, which eliminates upfront costs related to resource setup. You need to only reserve computing resources to handle your daily business traffic.

• Flexible scaling

  By preparing the configurations for servers to be scaled out in advance, you can easily enable automatic scaling with just a few clicks. This significantly reduces resource and O&M costs.

Prerequisites

Step 1: Create a scaling group

A scaling group is a collection of instances that meet your business requirements and serves as the core unit of Auto Scaling. Auto Scaling adjusts the number of instances in scaling groups by adding or removing them as needed.

1. Go to the Scaling Groups page.

   1. Log on to the Auto Scaling console.

   2. In the left-side navigation pane, click Scaling Groups.

   3. In the top navigation bar, select the region where Auto Scaling is activated.

2. In the upper-left corner of the Scaling Groups page, click Create.

3. On the Create by Form tab, configure the scaling group and click Create.

   The following table describes the parameter settings used in this topic. Parameters that are not covered in the following table default to their default settings. For information about how to create a scaling group, see Create scaling groups.

   Parameter	Example	Description
   Scaling Group Name	test	Enter a name for the scaling group. The name must follow the format requirements displayed on the UI.
   Type	ECS	Select ECS, which specifies that the scaling group contains ECS instances.
   Instance Configuration Source	Create from Scratch	Do not specify the template for automatically creating ECS instances at this stage. After the scaling group is created, you can proceed to create a scaling configuration.
   Minimum Number of Instances	1	Specify the minimum number of instances in the scaling group. If the number of instances in the scaling group falls below this value, Auto Scaling will add ECS instances until the desired minimum is reached.
   Maximum Number of Instances	5	Specify the maximum number of instances in the scaling group. If the number of instances exceeds this value, Auto Scaling will remove ECS instances until the number of instances falls below the specified limit.
   VPC	vpc-bp1jmxxau0lur929p****	Select a VPC for the ECS instances in the scaling group.
   vSwitch	vsw-2zeknnyw2ewufbs4z**** vsw-2zesy03h8eaf9fe0l****	Select one or more vSwitches for the ECS instances in the scaling group. We recommend that you select multiple vSwitches to improve the success rate of scale-out events.

Step 2: Create a scaling configuration and enable the scaling configuration and scaling group

A scaling configuration is a template used to create ECS instances during scale-out events. It includes information such as the billing method, instance type, storage, and network settings. After you create a scaling configuration, you can enable the scaling configuration and then enable the scaling group.

1. Find the desired scaling group and use one of the following methods to open the scaling group details page.

   • Click the ID of the scaling group in the Scaling Group Name/ID column.

   • Click Details in the Actions column.

2. In the upper part of the details page, click the Instance Configuration Sources tab.

3. On the Scaling Configurations tab, click Create Scaling Configuration.

4. On the Create Scaling Configuration page, configure parameters to create a scaling configuration and then click Create.

   The following table describes the parameter settings used in this topic. Parameters not covered in the following table default to their default settings. For more information about how to create a scaling configuration, see Create a scaling configuration of the ECS type.

   Section	Parameter	Example	Description
   Basic Information	Scaling Configuration Name	test	Enter a name for the scaling configuration. The name must follow the format requirements displayed on the UI.
   	Billing Method	Pay-as-you-go	Auto Scaling is free. However, charges apply for ECS instances created during scale-out events. In this example, the pay-as-you-go billing method is used. For more information, see Billing overview of ECS.
   Image and Instance	Instance Configuration Mode	Specify Instance Pattern	Select Specify Instance Pattern to choose specifications for ECS instances.
   	Instance Attribute Combination	2 vCPUs, 4 GiB Memory, Enterprise Level	Select the appropriate number of vCPUs and memory size for ECS instances based on your business requirements.
   	Select Image	Public Image: Alibaba Cloud Linux 3.2104 LTS 64-bit	Select an image to deploy ECS instances. This example uses a public image. In real-world scenarios, you can choose a custom image specific to your application.
   Storage	System Disk	Enterprise SSD (ESSD), 40 GiB, and PL0	Select a system disk for ECS instances.
   Network and Security Group	Public IP Address	Assign Public IPv4 Address, Pay-by-bandwidth, and 1 Mbit/s bandwidth	Specify whether to assign public IP addresses to ECS instances. Outbound public bandwidth is charged separately, and the fees are included in your ECS instance costs.
   	Security Group	sg-bp18kz60mefsicfg****	Select an existing security group. For information about how to create a security group, see Create a security group.
   Management Settings	Logon Credentials	Set Later	Select Set Later, which requires you to manually configure passwords for ECS instances after you create the instances.

5. In the Preview Scaling Configuration dialog box, confirm the information and click Create.

6. In the The scaling configuration is created. message, click Enable.

7. In the Enable Scaling Configuration dialog box, click OK.

   Note

   In a scaling group, you must enable one scaling configuration. After you enable a scaling configuration, the scaling configuration enters the Active state.

8. In the Enable Scaling Group message, click OK.

   The scaling group must be enabled to allow Auto Scaling to scale instances automatically based on your business requirements.

   In this example, the Minimum Number of Instances parameter is set to 1. When you enable the scaling group, Auto Scaling automatically creates one ECS instance from the enabled scaling configuration. You can go to the Instances tab of the scaling group details page and check the instance information on the Auto Created tab.

   

Step 3: Create scaling rules

A scaling rule defines whether to add or remove instances from a scaling group.

1. On the details page of the scaling group, click the Scaling Rules and Event-triggered Tasks tab. Then, click the Scaling Rules tab.

2. Click Create Scaling Rule, configure parameters to create the scaling rule, and then click OK.

   In this example, simple scaling rules are created. For more information about how to create a scaling rule, see Configure scaling rules.

   Parameter	Description
   Rule Name	Enter a name for the scaling rule. The name must follow the format requirements displayed on the UI.
   Rule Type	The type of the scaling rule. In this example, select Simple Scaling Rule. For more information about scaling rules, see Overview.
   Operation	Specify the number of instances to add or remove when the scaling rule is executed. The number of instances added or removed during each scaling event must not exceed 1,000.
   Cooldown Time	Optional. Specify the cooldown period for the scaling rule. Unit: seconds. If you do not configure this parameter, the cooldown period of the scaling group takes effect. For more information, see Cooldown period.

   Repeat this step to create scale-out and scale-in rules. The following table describes the configurations used in this example.

   Scaling rule	Sample configuration
   Scale-out rule	Rule Name: add Rule Type: Simple Scaling Rule Operation: Add 1 Instance
   Scale-in rule	Rule Name: remove Rule Type: Simple Scaling Rule Operation: Remove 1 Instance.

Step 4: Manually execute scaling rules to scale ECS instances

You can manually execute scaling rules based on your business needs. Auto Scaling automatically adds or removes ECS instances based on the defined scaling rules to adjust the instance count in your scaling group.

1. On the details page of the scaling group, click the Scaling Rules and Event-triggered Tasks tab. Then, click the Scaling Rules tab.

2. Find the scaling rule that you want to manually execute and click Execute in the Actions column.

   In this example, the following operations are performed to verify the scaling effect:

   • Execute the scale-out rule to check whether an ECS instance is automatically created in the scaling group.

     

   • Execute the scale-in rule to check whether an ECS instance is automatically removed from the scaling group.