Virtual Server Auto-Scaling

• 1: Overview
• 1.1: Monitoring Metrics
• 1.2: ServiceWatch Metrics
• 2: How-to guides
• 2.1: Launch Configuration
• 2.2: Manage Policy
• 2.3: Manage Schedule
• 2.4: Manage Notification
• 3: API Reference
• 4: CLI Reference
• 5: Release Note

1 - Overview

Service Overview

Virtual Server Auto-Scaling is a service that automatically scales resources up or down based on demand. You can add or terminate servers running the application according to predefined conditions or schedules.
An Auto-Scaling Group uses a pre-created Launch Configuration as a configuration template to launch servers, and can adjust and manage the number of servers. It adjusts to ensure the number of servers does not fall below the specified minimum or exceed the specified maximum.
If you register a schedule with an Auto-Scaling Group, you can set the number of servers according to the specified schedule. If you register a policy, you can increase or decrease the number of servers based on predefined conditions.

Features

• Easy and convenient computing environment setup: Through a web-based Console, users can easily configure the required computing environment themselves via Self Service, from creating Launch Configurations to creating/modifying/deleting Auto-Scaling Groups.

• Elastic Resource Usage: Computing resources can be used elastically according to the service load and usage. Users can schedule resource usage for predictable specific time periods, and can adjust resource consumption to accommodate temporary access by an unspecified large number of users.

• Availability Improvement: Virtual Server Auto-Scaling provides a function that adjusts resources to match variable demand so that the traffic required by the user can always be handled. Through this, users can achieve improved application performance and availability.

• Maximize Cost Savings: You can reduce unnecessary expenses by using resources only as needed according to demand fluctuations. By flexibly allocating resources in response to traffic increases or decreases during specific periods such as nights, weekends, and month-ends, you can maximize cost-saving effects.

Service Architecture Diagram

Provided features

Virtual Server Auto-Scaling provides the following features.

• Launch Configuration: It is a configuration template used to create a Virtual Server in an Auto-Scaling Group. When creating a Launch Configuration, you set information about the Virtual Server such as the image, server type, Key Pair, Block Storage, etc.
• Server Count Adjustment: Provides several ways to adjust the number of servers. By using policies, you can add a Virtual Server when load exceeds a threshold and release the Virtual Server when demand is low, maintaining application availability while reducing costs. You can also add and release Virtual Servers according to a predefined schedule, and manually adjust the number of servers in an Auto-Scaling Group as needed.
• Load Balancer Integration: You can use a Load Balancer to evenly distribute application traffic across Virtual Servers. Whenever a Virtual Server is added or removed, it is automatically registered with or deregistered from the Load Balancer.
• Network Connection: You can connect the Auto-Scaling Group’s standard subnet, automatic IP allocation, and Public NAT IP. Provides a local subnet connection for inter-server communication.
• Security Group Application: Security Group is a virtual logical firewall that controls inbound/outbound traffic generated on a Virtual Server. Inbound rules control incoming traffic to the Virtual Server, and outbound rules control outgoing traffic from the Virtual Server.
• Monitoring: You can view monitoring data such as CPU, Memory, and Disk of Virtual Servers created in an Auto-Scaling Group via the ServiceWatch service. Based on the monitoring data, you can set load thresholds using Auto-Scaling policies, and when thresholds are exceeded, you can add or remove servers.

Component

Virtual Server Auto-Scaling creates an Auto-Scaling Group through a Launch Configuration and monitors and manages the servers.

Launch Configuration

This is a Configuration template used to create a Virtual Server in an Auto-Scaling Group. The main features are as follows.

• Image: Provides OS standard images and Custom images created by the user. Users can select and use them according to the service they wish to configure.
• Keypair: Provides the Keypair method for secure OS access.
• Init script: Users can define a script to be executed when the Virtual Server starts.
• For more details, refer to Launch Configuration Create.

Auto-Scaling Group

Launch Configuration is used as a pre-configuration template for creating servers. By creating an Auto-Scaling Group, you can adjust and manage the number of servers. The main features are as follows.

• Launch Configuration: A Configuration template used to create a Virtual Server in an Auto-Scaling Group.
• Server Count Setting: Virtual Server Auto-Scaling provides several ways to adjust the number of servers in an Auto-Scaling Group.
  • Fixed Server Count Method: When creating an Auto-Scaling Group, this method keeps the default settings using the configured number of servers without any additional schedules or policies. Refer to Create Auto-Scaling Group to set the Min, Desired, and Max server counts.
  • Server Count Manual Adjustment Method: In an Auto-Scaling Group, you can increase or decrease the number of servers by modifying the server count to the desired amount. You can choose whether to manually set the desired server count. Please refer to 서버 수 수정하기.
  • Schedule reservation method: You can schedule daily, weekly, monthly, or one-time, and set the desired number of servers at the specified time. This is useful when you can predict when to scale the number of servers up or down. If you use the schedule method, please refer to Manage Schedules to add and manage schedules.
  • Policy Mode: You can use a policy to dynamically adjust servers. When a monitoring metric exceeds a configured threshold, the number of servers is adjusted. At this time, you can choose one of three methods to adjust the server count: increase or decrease by a specified number, increase or decrease by a specified percentage, or fix the server count to a given value. When servers are started or terminated due to a policy, the monitoring metric (CPU utilization) may temporarily exceed the threshold registered in the policy. However, because this is a brief moment, a cooldown period is set to avoid treating it as an abnormal situation. If you want to use the policy mode, see Managing Policies.
• Load Balancer: Automatically connects and disconnects to the Load Balancer registered in the Auto-Scaling Group whenever a Virtual Server is added or terminated.
  • Refer to Auto-Scaling Group Detailed Information for detailed information about the Load Balancer of an Auto-Scaling Group.

Constraints

The constraints of Virtual Server Auto-Scaling are as follows.

Prior Service

This is a list of services that must be pre-configured before creating the service. Please refer to the guide provided for each service and prepare in advance.

1.1 - Monitoring Metrics

Virtual Server Auto-Scaling is a service provided for Virtual Servers that offers individual Virtual Server monitoring metrics and monitoring metrics provided by policies based on Cloud Monitoring.

Virtual Server Monitoring Metrics

The table below shows the monitoring metrics of Virtual Server that can be viewed through Cloud Monitoring. For detailed usage of Cloud Monitoring, refer to the Cloud Monitoring guide.

Memory-related metrics are not provided for Windows OS.

Monitoring metrics provided by Cloud Monitoring-based policies

The table below shows the monitoring metrics provided by the policy of a Cloud Monitoring‑based Auto‑Scaling Group. For detailed information on policy settings based on Cloud Monitoring, see 정책 관리하기.

1.2 - ServiceWatch Metrics

Virtual Server Auto-Scaling is a service provided for Virtual Servers that offers individual Virtual Server monitoring metrics and monitoring metrics supplied by ServiceWatch-based policies.

Virtual Server Monitoring Metrics

The basic metrics provided by Virtual Server can be found in ServiceWatch > Virtual Server Basic Metrics.

ServiceWatch monitoring metrics provided by the Auto-Scaling Group policy

The table below shows the ServiceWatch monitoring metrics provided by the Auto-Scaling Group policy. For detailed information on configuring Auto-Scaling Group policies, see Managing Policies.

2 - How-to guides

Users can create the service by entering the required information for an Auto-Scaling Group and selecting detailed options through the Samsung Cloud Platform Console.

Create Auto-Scaling Group

You can create and use the Auto-Scaling Group service from the Samsung Cloud Platform Console.

To create an Auto-Scaling Group, follow these steps.

1. Click the All Services > Compute > Virtual Server menu. Navigate to the Service Home page of Virtual Server.

2. Click the Auto-Scaling Group menu. You will be taken to the Auto-Scaling Group List page.

3. On the Auto-Scaling Group List page, click the Create Auto-Scaling Group button. You will be taken to the Create Auto-Scaling Group page.

4. On the Auto-Scaling Group Creation page, enter the information required to create the service.

   • In the Launch Configuration area, select the Launch Configuration.
     • Launch Configuration creation button can be clicked to create a new Launch Configuration.
   • Enter or select the required information in the Service Information Input area.

     Category	Whether required	Detailed description
     Auto-Scaling Group name	Required	Auto-Scaling Group name Manage servers of the same type and purpose as a group
     Server name	Required	Server name to be created within the Auto-Scaling Group The server name is automatically assigned as a combination of the entered server name and a sequence, serving as an identifier to distinguish servers created within the Auto-Scaling Group.
     Number of servers	Required	Number of servers to create in the Auto-Scaling Group Enter a value between 0 and 20 (Min≤Desired≤Max) Min: Set the minimum number of servers the Auto-Scaling Group should maintain Desired: Set the target number of servers within the Auto-Scaling Group; also indicates the number of servers initially created when the Auto-Scaling Group is created Max: Set the maximum number of servers the Auto-Scaling Group can maintain After creating the Auto-Scaling Group, you can adjust the settings using the Edit button. For details, see Modify Server Count
     Desired server count manual setting	Selection	Select whether to manually change the Desired number of servers Even after creating the Auto-Scaling Group, configure it via the Edit button. For details, refer to Manually edit Desired server count
     Network Settings > Network Settings	Required	Network settings for Auto-Scaling Group Select the desired VPC and standard Subnet IP can only be auto-generated. When you select local Subnet, you can choose the desired local Subnet, and IP can only be auto-generated
     Network Settings > Security Group	Selection	To allow required connections, you need to configure a Security Group If you do not configure a Security Group, all inbound and outbound traffic will be blocked according to the default rule (Any/Deny) For Linux servers, allow SSH traffic For Windows servers, allow RDP traffic Even after creating an Auto-Scaling Group, configure it using the modify button. For details, refer to Configure Security Group
     Load Balancer	Selection	Connect the Auto-Scaling Group to a Load Balancer Register the Auto-Scaling Group’s servers as members of the LB server group LB server group: Select a LB server group that exists in the chosen VPC Port: Enter a value between 1 and 65,534 Press the + button to add an LB server group (up to a total of three LB server groups and ports are allowed) LB server groups that use Weighted Round Robin or Weighted Least Connection load balancing cannot be selected Draining Timeout value: After checking Draining Timeout as Enabled, you can set the Draining Timeout value Draining Timeout: The waiting period before removing a server from the Load Balancer Since sessions may remain connected to the server, setting a Draining Timeout and waiting allows safe session termination If the Load Balancer is unused, Draining Timeout cannot be set The default is 300 seconds; you can enter a value from 1 second up to 3,600 seconds. Changes can be made after creating the Auto-Scaling Group; for details, see Using Auto-Scaling Group Load Balancer

     Table. Auto-Scaling Group service information input items
   • In the Scaling policy setting area, set the scaling policy.
     • For detailed information on policy settings, refer to Add Policy.

       Category	Required	Detailed description
       Current setting	Selection	Set scaling policy now Add Policy button click shows policy information input fields
       Set later	Selection	After creating an Auto-Scaling Group, set policies on the detail information page

       Table. Auto-Scaling Group scaling policy configuration items
   • In the Notification Settings area, configure the notification recipients and notification method.
     • For detailed information on notification settings, see Add Notification.

       Category	Required?	Detailed description
       Current setting	Selection	Set the notification recipients and notification method now Click the Add Notification button to open the Add Notification popup For detailed information about notification settings, see the details In the notification recipients list, click the Edit button to modify the notification information
       Set later	Selection	After creating an Auto-Scaling Group, set the notification recipients and notification method on the details page.

       Table. Auto-Scaling Group notification configuration items
   • In the Additional Information Input area, enter or select the required information.

     Category	Required status	Detailed description
     Status check	Selection	Check the status of Virtual Server and Load Balancer and replace servers that are Unhealthy Virtual Server status check: Enabled is the default and cannot be changed Load Balancer status check: Enabled only when a Load Balancer is connected in the service information input area Grace period: Set the time to defer status checks until the newly added server operates normally Enter 0 to disable the status check grace period
     tag	Selection	Add Tag Up to 50 per resource can be added After clicking the Add Tag button, enter or select Key, Value values

     Table. Auto-Scaling Group additional information input fields

     Caution

     A server that the user changes to Stop is not considered Unhealthy, so even when using the health check feature, the server will not be replaced.

5. Summary Check the detailed information and estimated billing amount generated in the panel, and click the Create button.

   • When creation is complete, check the created Auto-Scaling Group on the Auto-Scaling Group list page.

Check detailed information of Auto-Scaling Group

Auto-Scaling Group service allows you to view and edit the full resource list and detailed information. The Auto-Scaling Group Details page is composed of Details, Policies, Schedule, Virtual Server, Load Balancer, Tags, Operation History tabs.

To view detailed information about the Auto-Scaling Group, follow these steps.

1. Click the All Services > Compute > Virtual Server menu. Navigate to the Service Home page of Virtual Server.
2. Click the Auto-Scaling Group menu. You will be taken to the Auto-Scaling Group List page.
3. On the Auto-Scaling Group List page, click the resource to view detailed information. You will be taken to the Auto-Scaling Group Details page.
   • Auto-Scaling Group Details page displays status information and additional feature information, and consists of Details, Policies, Schedule, Virtual Server, Load Balancer, Tags, Activity History tabs.

     Category	Detailed description
     Auto-Scaling Group status	Status of the Auto-Scaling Group created by the user Creating: Creating Auto-Scaling Group In Service: Serviceable state Scale In: Scale In in progress Scale Out: Scale Out in progress Cool Down: Cooling down Terminating: Terminating Auto-Scaling Group Attach to LB: Attaching to Load Balancer Detach from LB: Detaching from Load Balancer
     Delete Auto-Scaling Group	Button to delete Auto-Scaling Group

     Table. Auto-Scaling Group status information and additional features

Detailed Information

Auto-Scaling Group List page lets you view detailed information of the selected resource and modify it if necessary.

Policy

On the Auto-Scaling Group List page, you can view the policy list of the selected resource and, if needed, add or manage policies.

Schedule

On the Auto-Scaling Group List page, you can view the schedule list of the selected resource and, if necessary, add or manage schedules.

Virtual Server

Auto-Scaling Group List You can view the Virtual Server list of the selected resource on the page.

Load Balancer

On the Auto-Scaling Group List page, you can view the Load Balancer list of the selected resource, and, if needed, add or manage Load Balancers.

Notification

Auto-Scaling Group List page allows you to view the notification recipients and notification methods for the selected resource.

tag

Auto-Scaling Group List page lets you view the tag information of selected resources, and add, modify, or delete them.

Work History

You can view the operation history of the selected resource on the Auto-Scaling Group List page.

Auto-Scaling Group Managing Resources

If you need to manage a created Auto-Scaling Group, you can perform actions on the Auto-Scaling Group Details page.

Edit Launch Configuration

You can modify the Launch Configuration of an Auto-Scaling Group.

To modify the Launch Configuration of an Auto-Scaling Group, follow these steps.

1. Click the All Services > Compute > Virtual Server menu. Navigate to the Service Home page of Virtual Server.

2. Click the Auto-Scaling Group menu. You will be taken to the Auto-Scaling Group list page.

3. On the Auto-Scaling Group List page, click the resource you want to edit the Launch Configuration for. You will be taken to the Auto-Scaling Group Details page.

4. Launch Configuration name. Click the Edit button. The Launch Configuration Edit popup opens. You can view the list of selectable Launch Configurations.

   Category	Detailed description
   Launch Configuration name	Launch Configuration name
   image	Launch Configuration OS Image
   Server type	Launch Configuration server type
   Block Storage	Launch Configuration Block Storage Settings
   Number of Auto-Scaling Groups	Number of Auto-Scailg Groups with Launch Configuration applied
   View Details	Button to view Launch Configuration details

   Table. Launch Configuration list items

5. In the Launch Configuration Edit popup, select the Launch Configuration to modify, then click the Confirm button. The Launch Configuration Edit Notification popup opens. Check the message in the Launch Configuration Edit Notification popup and click the Confirm button.

Edit server count

You can modify the number of servers in the Auto-Scaling Group.

To modify the number of servers in an Auto-Scaling Group, follow these steps.

1. Click the All Services > Compute > Virtual Server menu. Navigate to the Service Home page of Virtual Server.
2. Click the Auto-Scaling Group menu. You will be taken to the Auto-Scaling Group list page.
3. On the Auto-Scaling Group List page, click the resource to edit the server count. You will be taken to the Auto-Scaling Group Details page.
4. Click the Edit button for server count. The Edit Server Count popup opens.
5. Modify Server Count In the popup window, after entering the required fields, click the Confirm button.

   Category	Required	Detailed description
   Number of servers > Min	Required	Minimum number of servers to modify Set the number of servers that the Auto-Scaling Group should maintain at a minimum
   Number of servers > Desired	Required	Target server count to modify Set the target server count within the Auto-Scaling Group Desired server count manual setting is disabled; you cannot modify the Desired server count. To modify the Desired server count, see Desired server count manual setting modification
   Number of servers > Max	Required	Target number of servers to modify Set the maximum number of servers the Auto-Scailg Group can maintain

   Table. Auto-Scailg Group server count modification items

Terminate Virtual Server Created by Auto-Scaling Group

Virtual Servers created in an Auto-Scaling Group can be terminated by clicking the terminate button on the Virtual Server’s detail page or by modifying the server count.

Cancel on the Virtual Server detail page

To cancel a Virtual Server on the Virtual Server detail page, follow these steps.

1. Click the All Services > Compute > Virtual Server menu. Navigate to the Service Home page of Virtual Server.
2. On the Service Home page, click the Virtual Server menu. You will be taken to the Virtual Server List page.
3. On the Virtual Server List page, select the Virtual Server created by the Auto-Scaling Group. Navigate to the Virtual Server Details page.
4. Click the Cancel Service button on the Virtual Server Details page. A popup confirming the server termination will appear.
5. Click the Confirm button. Server termination is complete.

Cancel by adjusting the server count

To cancel a Virtual Server by modifying the server count, follow the steps below.

1. Click the All Services > Compute > Virtual Server menu. Navigate to the Service Home page of Virtual Server.
2. Click the Auto-Scaling Group menu. Navigate to the Auto-Scaling Group List page.
3. On the Auto-Scaling Group List page, click the resource to terminate the Virtual Server. You will be taken to the Auto-Scaling Group Details page.
4. Click the Edit button of the Server Count item. The Server Count Edit popup opens.
5. Server Count Edit In the popup window, after reducing the Desired number, click the Confirm button. As the Desired server count is adjusted, the Virtual Server will be terminated.

Modify manual setting of desired server count

You can manually change the Desired server count of the Auto-Scaling Group.

To modify the manual setting of the Desired server count for an Auto-Scaling Group, follow these steps.

1. Click the All Services > Compute > Virtual Server menu. Navigate to the Service Home page of Virtual Server.
2. Click the Auto-Scaling Group menu. You will be taken to the Auto-Scaling Group List page.
3. On the Auto-Scaling Group List page, click the resource to manually change the Desired server count. You will be taken to the Auto-Scaling Group Details page.
4. Click the Edit button for the server count. The Desired server count manual setting popup opens.
5. Desired server count manual setting After selecting whether to use it in the popup window, click the Confirm button.

Configure Security Group

You can configure the Security Group of an Auto-Scaling Group.

Follow these steps to configure the Security Group of an Auto-Scaling Group.

1. Click the All Services > Compute > Virtual Server menu. Navigate to the Service Home page of Virtual Server.

2. Click the Auto-Scaling Group menu. You will be taken to the Auto-Scaling Group List page.

3. On the Auto-Scaling Group List page, click the resource to configure the Security Group. You will be taken to the Auto-Scaling Group Details page.

4. Click the Edit button for Security Group. Security Group Edit popup opens. You can view the list of selectable Security Groups.

   Category	Detailed description
   Security Group name	Security Group name

   Table. Security Group list items

5. Security Group edit In the popup window, after selecting the Security Group, click the Confirm button. Security Group edit notification popup opens. Check the message of the Security Group edit notification popup and click the Confirm button.

Change status check

You can configure it to check the status of Virtual Server and Load Balancer and automatically replace servers that are in an Unhealthy state.

1. Click the All Services > Compute > Virtual Server menu. Go to the Service Home page of Virtual Server.
2. Click the Auto-Scaling Group menu. Go to the Auto-Scaling Group list page.
3. On the Auto-Scaling Group List page, click the resource for which you want to change the Load Balancer health check function. You will be taken to the Auto-Scaling Group Details page.
4. Click the Edit button of Status Check. Status Check Edit popup window opens.
5. Status Check Edit In the popup, choose whether to enable Load Balancer Status Check.
6. After entering the Grace period, click the Confirm button.
   • If you do not want to use the grace period, set the grace period to 0.

Manage Additional Information for Auto-Scaling Group

You can set the Load Balancer of an Auto-Scaling Group to enabled and select the LB server group. For an Auto-Scaling Group that is using a Load Balancer, you can change it to disabled.

Modify Load Balancer Draining Timeout

You can set the Load Balancer Draining Timeout of an Auto-Scaling Group.

To set the Load Balancer Draining Timeout of an Auto-Scaling Group, follow these steps.

1. Click the All Services > Compute > Virtual Server menu. Navigate to the Service Home page of Virtual Server.
2. Click the Auto-Scaling Group menu. You will be taken to the Auto-Scaling Group List page.
3. Auto-Scaling Group List page, click the resource to set the Load Balancer Draining Timeout. You will be taken to the Auto-Scaling Group Details page.
4. Click the Load Balancer tab. You will be taken to the Load Balancer list page.
5. Click the Edit button for Draining Timeout. The Draining Timeout Edit popup opens.
6. Draining Timeout Edit In the popup window, select whether to use Draining Timeout, and enter the Draining Timeout duration (seconds).
7. Draining Timeout Edit After verifying the input values in the popup window, click the Confirm button. Draining Timeout Edit Notification popup window opens. Check the message in the notification popup and click the Confirm button.

Using Load Balancer

You can modify the Load Balancer of an Auto-Scaling Group. To configure the Load Balancer of an Auto-Scaling Group, follow these steps.

1. Click the All Services > Compute > Virtual Server menu. Navigate to the Service Home page of Virtual Server.
2. Click the Auto-Scaling Group menu. Navigate to the Auto-Scaling Group List page.
3. On the Auto-Scaling Group List page, click the resource that will use the Load Balancer. Navigate to the Auto-Scaling Group Details page.
4. Click the Load Balancer tab. You will be taken to the Load Balancer list page.
5. Click the Edit button of the Load Balancer. The Load Balancer Edit popup opens.
6. Load Balancer Edit Please select whether to use it in the popup. Selecting Use allows you to choose a Load Balancer.

   Category	Detailed description
   LB server group	LB server group name Select the LB server group that is created in the selected VPC LB server groups that use Weighted Round Robin or Weighted Least Connection load balancing cannot be selected
   Port	Port information of the LB server group When registering as a member of the LB server group, enter the required port information in the registration details. Enter a value between 1 and 65,534

   Table. Load Balancer list items
   • Click the + button to add an LB server group. Up to three are allowed. Click the X button to remove the added Load Balancer.
7. Check the Load Balancer list and click the Confirm button. Load Balancer Modification Notification popup opens. Verify the message in the notification popup and click the Confirm button.

Not Using Load Balancer

You can modify the Auto-Scaling Group’s Load Balancer to be unused. To set the Auto-Scaling Group’s Load Balancer to unused, follow these steps.

1. Click the All Services > Compute > Virtual Server menu. Go to the Service Home page of Virtual Server.
2. Click the Auto-Scaling Group menu. You will be taken to the Auto-Scaling Group List page.
3. On the Auto-Scaling Group List page, click the resource to change the Load Balancer to unused. You will be taken to the Auto-Scaling Group Details page.
4. Click the Load Balancer tab. You will be taken to the Load Balancer list page.
5. Click the Edit button of the Load Balancer. The Load Balancer Edit popup opens.
6. Load Balancer edit Choose whether to use it in the popup window. If you deselect Use, Load Balancer will no longer be used.
7. Use deselection, and click the Confirm button. Load Balancer Modification Notification popup opens. Verify the message in the notification popup and click the Confirm button.

Delete Auto-Scaling Group

Deleting an unused Auto-Scaling Group can reduce operational costs. However, terminating an Auto-Scaling Group may cause the running service to stop immediately, so you should thoroughly consider the impact of service interruption before proceeding with the termination.

To terminate an Auto-Scaling Group, follow these steps.

1. Click the All Services > Compute > Virtual Server menu. Navigate to the Service Home page of Virtual Server.
2. Click the Auto-Scaling Group menu. Navigate to the Auto-Scaling Group List page.
3. On the Auto-Scaling Group List page, click the resource to terminate. Navigate to the Auto-Scaling Group Details page.
4. Click the Auto-Scaling Group Delete button.
5. After the deletion is complete, verify that the resource has been removed on the Auto-Scaling Group List page.

2.1 - Launch Configuration

To create an Auto-Scaling Group, a Launch Configuration must be created in advance.

Create Launch Configuration

You can create and use the Launch Configuration service in the Samsung Cloud Platform Console.

To create a Launch Configuration, follow these steps.

1. Click the All Services > Compute > Virtual Server menu. Navigate to the Service Home page of Virtual Server.

2. Click the Launch Configuration menu. Navigate to the Launch Configuration List page.

3. On the Launch Configuration list page, click the Create Launch Configuration button. You will be taken to the Create Launch Configuration page.

4. On the Launch Configurationp Creation page, in the Image and Version Selection area, select the required information and click the Next button.

   Reference

   Please refer to the server type in Virtual Server OS Image Provisioning Versions for images selectable in Launch Configuration.

5. Enter the required information in the Service Information Input area of the Launch Configurationp Creation page.

   Category	Required status	Detailed description
   Launch Configuration name	Required	Launch Configuration name Name used to distinguish the Launch Configuration
   Service Type > Server Type	Required	Launch Configuration server type Standard: Standard specifications commonly used High Capacity: Large-scale server specifications beyond Standard Refer to Virtual Server Server Type for selectable server types
   Block Storage	Required	Configure Block Storage according to the purpose of the Launch Configuration Basic OS: The area where the OS is installed and used Enter the size in Units, and the minimum size varies depending on the OS image type Alma Linux: Enter a value between 2 and 1,536 Oracle Linux: Enter a value between 5 and 1,536 RHEL: Enter a value between 2 and 1,536 Rocky Linux: Enter a value between 2 and 1,536 Ubuntu: Enter a value between 1 and 1,536 Windows: Enter a value between 4 and 1,536 SSD: High‑performance general volume HDD: General volume SSD/HDD_KMS: Additional encrypted volume using Samsung Cloud Platform KMS (Key Management System) encryption keys Encryption can be applied only at initial creation and cannot be changed afterward Performance degradation occurs when using the SSD_KMS disk type Additional: Use when extra space beyond the OS area is needed After selecting Use, enter the storage type and size Click the + button to add storage, or the x button to delete (up to 25 can be added) Enter the size in Units, with a value between 1 and 1,536 Since 1 Unit equals 8 GB, this creates 8 GB to 12,288 GB SSD: High‑performance general volume HDD: General volume SSD/HDD_KMS: Additional encrypted volume using Samsung Cloud Platform KMS (Key Management System) encryption keys Encryption can be applied only at initial creation and cannot be changed afterward Performance degradation occurs when using the SSD_KMS disk type SSD_MultiAttach: Volume that can be attached to more than one server For details on each Block Storage type, see Create Block Storage
   Keypair	Required	Select the user authentication method for the Launch Configuration Server authentication information for accessing the servers created by generating an Auto-Scaling Group with a Launch Configuration New creation: Create a new one if a new Keypair is required Refer to Create Keypair for how to create a new Keypair Default login account list by OS Alma Linux: almalinux RHEL: cloud-user Rocky Linux: rocky Ubuntu: ubuntu Windows: sysadmin
   File Storage Settings	Selection	Scale-out/Scale-in can be set to automatically connect File Storage Volume: After clicking the Select button, choose the Volume to use in the Select File Storage popup Up to 5 can be selected The selected Volume can be deleted by clicking the X button

   Table. Launch Configuration service information input items

6. On the Launch Configuration Creation page, after entering information in the Additional Information Input area, click the Next button.

   Category	Required	Detailed description
   Init Script	Selection	Script that runs when the server of an Auto Scaling Group using a Launch Configuration starts Enter within 45,000 bytes The init script must be a batch script for Windows, a shell script for Linux, or cloud‑init, depending on the selected image.
   tag	Selection	Add Tag Up to 50 can be added per resource After clicking the Add Tag button, enter or select Key, Value values

   Table. Launch Configuration additional information input fields

7. Verify creation information Check the information you entered on the page and the estimated amount, and click the Create button.

   • When creation is complete, verify the created Launch Configuration on the Launch Configuration List page.

View Launch Configuration Details

The Launch Configuration service allows you to view and edit the full list of resources and detailed information. Launch Configuration Details page consists of Details, Tags, Activity Log tabs.

To view detailed information of the Launch Configuration, follow these steps.

1. Click the All Services > Compute > Virtual Server menu. Navigate to the Service Home page of Virtual Server.
2. Click the Launch Configuration menu. Navigate to the Launch Configuration List page.
3. On the Launch Configuration List page, click the resource you want to view detailed information for. You will be taken to the Launch Configuration Details page.
   • Launch Configuration Details At the top of the page, status information and additional feature information are displayed, and it consists of Details, Tags, Activity History tabs.

     Category	Detailed description
     Launch Configuration status	User-created Launch Configuration status Active: Available
     Delete Launch Configuration	Delete Launch Configuration button

     Table. Launch Configuration status information and additional features

Detailed information

Launch Configuration list page allows you to view detailed information of the selected resource and edit the information if needed.

tag

Launch Configuration List page lets you view the tag information of the selected resource, and you can add, modify, or delete it.

Work History

You can view the operation history of the selected resource on the Launch Configuration List page.

Delete Launch Configuration

Deleting unused Launch Configurations can reduce operational costs. However, terminating a Launch Configuration may cause running services to stop immediately, so you should carefully consider the impact of service interruption before proceeding with the termination.

To delete a Launch Configuration, follow these steps.

1. Click the All Services > Compute > Virtual Server menu. Navigate to the Service Home page of Virtual Server.
2. Click the Launch Configuration menu. Go to the Launch Configuration List page.
3. On the Launch Configuration List page, click the resource to be terminated. Navigate to the Launch Configuration Details page.
4. Launch Configuration Delete Click the button.
5. After deletion is complete, verify on the Launch Configuration List page that the resource has been removed.

2.2 - Manage Policy

You can dynamically adjust the number of servers in an Auto-Scaling Group based on monitoring metrics. When the metric exceeds the threshold you set, the server count is adjusted. At that time, you can choose one of three methods to adjust the server count: increase or decrease by a specified number, increase or decrease by a specified percentage, or fix the server count to a given value. When servers are launched or terminated due to a policy, the monitoring metric, such as CPU utilization, may temporarily exceed the threshold registered in the policy. However, because this is a brief moment, a cooldown period is set to avoid treating it as an abnormal condition. You can add and manage policies for an Auto-Scaling Group created in the Samsung Cloud Platform Console.

Add Policy

You can add policies to an Auto-Scaling Group. To add a policy to an Auto-Scaling Group, follow these steps.

1. Click the All Services > Compute > Virtual Server menu. Navigate to the Service Home page of Virtual Server.

2. Click the Auto-Scaling Group menu. You will be taken to the Auto-Scaling Group List page.

3. Auto-Scaling Group List page, click the resource you want to view detailed information for. You will be taken to the Auto-Scaling Group Details page.

4. Click the Policy Tab. You will be taken to the Policy Tab page.

5. Click the Add Policy button. The Add Policy popup window opens.

   Category	Required	Detailed description
   Category	Required	Policy Category Scale In: return server count Scale Out: increase server count
   Policy Name	Required	Name for policy-specific categorization
   Execution conditions	Required	Conditions to execute the policy Statistic: How to calculate the Metric Type Average: Average of servers in the Auto-Scaling Group Min: Minimum value among servers in the Auto-Scaling Group Max: Maximum value among servers in the Auto-Scaling Group Metric Type: CPU Usage, Network In(bytes), Network Out(bytes), Network In(Packets), Network Out(Packets) Operator: >= > <= < Threshold: Threshold corresponding to the Metric Type Period: Continuous duration required to trigger the condition (the condition must be continuously satisfied for N minutes for the policy to execute)
   execution unit	Required	Policy execution method Policy Type: Select the type of policy to execute. Increase or decrease the number of servers by a specified count: Increase or decrease the server count to the Target Value Increase or decrease the number of servers by a specified ratio: Increase or decrease by the Target Value ratio Fix the number of servers to the entered value: Fix the server count according to the Target Value Target Value: The number or ratio to apply for the selected Policy Type
   cooldown	Required	The waiting time (seconds) when a server is started or terminated due to a policy The default is 300 seconds, and it can be set between a minimum of 60 seconds and a maximum of 3,600 seconds.

   Table. Add Policy Popup Items
   Reference

   Policy > Cooldown Settings

   • When a server is started or terminated due to a policy, it waits for the configured cooldown period. Temporarily, the monitoring metric CPU utilization may exceed the threshold defined in the policy. However, because this is a transient moment rather than a condition for adjusting the number of servers, it is not considered an abnormal situation, and the system waits by applying the cooldown time.
   guide

   Policy execution operates within the configured Min/Max server count range.

   • Even if you input values outside the Min/Max server count range—such as increasing, returning, or fixing the number of servers—it operates within the configured Min/Max server count.
   • Example: When the minimum number of servers is 3, even if you set the server count fixed to 1, the server count does not drop to 1 and remains at the minimum of 3.

6. Add Policy After entering the required values in the popup window, click the Confirm button. The added policy can be viewed in the Policy List.

Policy creation example

The following is an explanation of the policy example. Please refer to it when creating a policy.

Edit Policy

You can modify the policies of an Auto-Scaling Group. To modify the policies of an Auto-Scaling Group, follow these steps.

1. Click the All Services > Compute > Virtual Server menu. Navigate to the Service Home page of Virtual Server.

2. Click the Auto-Scaling Group menu. Navigate to the Auto-Scaling Group List page.

3. Auto-Scaling Group List page, click the resource to view detailed information. You will be taken to the Auto-Scaling Group Details page.

4. Click the Policy Tab. You will be taken to the Policy Tab page.

5. Click the More > Edit button for the policy you want to modify. The Policy Edit Popup opens.

   Category	Required	Detailed description
   Category	Required	Policy Classification Scale In: Return server count Scale Out: Increase server count
   Policy Name	Required	Name for policy-specific categorization
   Execution conditions	Required	Conditions to execute the policy Statistic: Method to calculate the Metric Type Average: Average of servers in the Auto-Scaling Group Min: Minimum value among servers in the Auto-Scaling Group Max: Maximum value among servers in the Auto-Scaling Group Metric Type: CPU Usage, Network In(bytes), Network Out(bytes), Network In(Packets), Network Out(Packets) Operator: >= > <= < Threshold: Threshold corresponding to the Metric Type Period: Continuous duration (in minutes) that triggers the execution condition
   execution unit	Required	Policy execution method Policy Type: Select the type of policy to execute. Increase or decrease the number of servers by a specified count: Increase or reduce the server count to the Target Value Increase or decrease the number of servers by a specified ratio: Increase or reduce by the Target Value ratio Fix the number of servers to the entered value: Fix the server count according to the Target Value Target Value: The number or ratio to execute the selected Policy Type
   Cool down	Required	The waiting time (seconds) when a server is started or terminated due to a policy The default is 300 seconds, and it can be set from a minimum of 1 second up to a maximum of 3,600 seconds

   Table. Policy edit popup items

6. Edit Policy In the popup window, after entering the required values, click the Confirm button.

Policy addition and modification constraints

When adding or modifying a policy, constraints exist based on the policy classification, execution conditions, and the scope of those conditions. Below is an example of constraints for the policy. Refer to the constraint examples to add or modify the policy.

Example 1 - Need to check for duplicate registration of policy classification/execution conditions

Policy classification (Scale Out or Scale In) and execution condition (Metric type) cannot be registered redundantly with the same values.

If a policy is registered as above, you cannot add a policy with the category (Scale Out) execution condition (Metric type=CPU Usage) or modify it to that condition.

Example 2 - Need to verify the execution condition range for execution conditions (Metric type) and execution conditions (Statistic) according to policy classification

When the policy type (Scale Out or Scale In) differs, duplicate registration of the execution condition range (Comparison operator + Threshold) is not allowed for the same execution condition (Metric type) and execution condition (Statistic).

If a policy is registered as shown above, you cannot add a policy as below or modify it under the following conditions.
If the average CPU Usage is 60% or higher, a Scale Out policy is already registered; therefore, registering a Scale In policy when the average CPU Usage is 60% or lower would duplicate the 60% execution condition and cannot be added.

Example 3 - Need to verify the execution condition range for execution conditions (Metric type) and execution conditions (Statistic) according to policy classification

When the policy classification (Scale Out or Scale In) differs, duplicate registration of the execution condition range (Comparison operator + Threshold) is not allowed for the same execution condition (Metric type) and execution condition (Statistic).

If a policy is registered as shown above, you cannot add a policy as below or modify it under the following conditions.
When the average CPU Usage is 10% or less, a Scale In policy is already registered; therefore, if the average CPU Usage is less than 60% / 60% or less / 10% or more / exceeds 9%, you cannot register a Scale Out policy because the execution condition ranges would overlap.

Example 4 - Execution conditions (Metric type) and execution conditions (Statistic) can be registered according to the execution condition range based on policy classification

If the policy type (Scale Out or Scale In) differs, you can register when the execution condition (Metric type) is the same but the execution condition (Statistic) is different, or when the execution condition range (Comparison operator + Threshold) does not overlap.

If a policy is already registered as shown above, you can add a policy as below or modify it with the following conditions. Registration is possible when the execution condition ranges do not overlap, or when the execution condition (Statistic) differs.

Delete Policy

You can delete a policy of an Auto-Scaling Group. To delete a policy of an Auto-Scaling Group, follow these steps.

1. Click the All Services > Compute > Virtual Server menu. Navigate to the Service Home page of Virtual Server.
2. Click the Auto-Scaling Group menu. Navigate to the Auto-Scaling Group List page.
3. Auto-Scaling Group List page: click the resource you want to view details for. You will be taken to the Auto-Scaling Group Details page.
4. Click the Policy Tab. You will be taken to the Policy Tab page.
5. Select the policy to delete and click the Delete button. The Policy Deletion Confirmation popup opens.
6. Policy Deletion Confirmation Check the popup window and click the Confirm button.

2.3 - Manage Schedule

You can schedule reservations daily, weekly, monthly, or one-time, and set the desired number of servers at the specified time. This is useful when you can predict when you need to decrease or increase the number of servers.

Add schedule

You can add a schedule to an Auto-Scaling Group. To add a schedule to an Auto-Scaling Group, follow these steps.

1. Click the All Services > Compute > Virtual Server menu. Navigate to the Service Home page of Virtual Server.
2. Click the Auto-Scaling Group menu. Navigate to the Auto-Scaling Group List page.
3. Auto-Scaling Group List page, click the resource you want to view detailed information for. You will be taken to the Auto-Scaling Group Details page.
4. Click the Schedule Tab. You will be taken to the Schedule Tab page.
5. Click the Add Schedule button. The Add Schedule popup window opens.

   Category	required	Detailed description
   Schedule name	Required	Name to distinguish by schedule
   Select server count	Required	Select the number of servers to adjust when executing the schedule Min: The minimum number of servers the Auto-Scailg Group should maintain Desired: The target number of servers within the Auto-Scailg Group Max: The maximum number of servers the Auto-Scailg Group can maintain
   Enter the number of servers	Required	Enter the value for the selected number of servers Min value: Enter a value between 0 and 50. (Min≤Desired≤Max) Desired value: Enter a value between 0 and 50. (Min≤Desired≤Max) Max value: Enter a value between 0 and 50. (Min≤Desired≤Max)
   Period	Required	Schedule execution frequency Daily: You can set the Start date, End date, and Permanent options for a daily schedule. You can also set the Time and Time zone Weekly: You can set the Start date, End date, Permanent options, and the Time and Time zone. You can also select the Day of week on which the weekly schedule will run. Monthly: You can set the Start date, End date, Permanent options, and the Time and Time zone. You can also enter the Date on which the monthly schedule will run One-time: You can set the Time and Time zone. You can also set the Date on which the one-time schedule will run
   Start date	Selection	Set schedule start date Cannot set a date earlier than the current date. The default is the current date.
   End date	Selection	Set schedule end date Cannot set a date earlier than the current date. The default is the current date plus 7 days.
   permanent	Selection	When configuring permanently, set the schedule end date to 9999-12-31
   time	Required	Schedule execution time setting Can be set in 30‑minute increments. Times earlier than the current date or current time cannot be set
   time zone	Required	Schedule execution time zone (example: Asia/Seoul (GMT +09:00))
   day of the week	Required	When Period is set to Weekly, select the Day of the week to execute the schedule
   Date	Required	When Period is set to Monthly, enter the Date on which the schedule will run Enter one or more values from -31 to 31, excluding 0. (Example: 3,4,5) When Period is set to Once, set the Date on which the schedule will run Setting a date earlier than the current date is not allowed. The default is the current date.

   Table. Schedule addition popup items
6. Add Schedule After entering the required values in the popup window, click the Confirm button.
7. Add Schedule Confirmation After checking the message in the popup window, click the Confirm button.

Modify schedule

You can modify the schedule of an Auto-Scaling Group. To modify the schedule of an Auto-Scaling Group, follow these steps.

1. Click the All Services > Compute > Virtual Server menu. Navigate to the Service Home page of Virtual Server.
2. Click the Auto-Scaling Group menu. Navigate to the Auto-Scaling Group List page.
3. On the Auto-Scaling Group List page, click the resource for which you want to view detailed information. You will be taken to the Auto-Scaling Group Details page.
4. Click the Schedule Tab. You will be taken to the Schedule Tab page.
5. Click the More > Edit button of the schedule you want to modify. The Edit Schedule popup window will open.

   Category	required	Detailed description
   Schedule name	Required	Name to distinguish by schedule
   Select number of servers	Required	Select the number of servers to adjust when executing the schedule Min: The minimum number of servers the Auto-Scailg Group should maintain Desired: The target number of servers within the Auto-Scailg Group Max: The maximum number of servers the Auto-Scailg Group can maintain
   Enter number of servers	Required	Enter the value for the selected number of servers Min value: Enter a value between 0 and 50. (Min≤Desired≤Max) Desired value: Enter a value between 0 and 50. (Min≤Desired≤Max) Max value: Enter a value between 0 and 50. (Min≤Desired≤Max)
   period	Required	Schedule execution frequency Daily: You can set the Start Date and End Date, and Permanent setting for the daily schedule. You can also set the Time and Time Zone Weekly: You can set the Start Date and End Date, Permanent setting, and the Time and Time Zone. You can also select the Day of Week for the Weekly schedule to run. Monthly: You can set the Start Date and End Date, Permanent setting, and the Time and Time Zone. You can also enter the Date for the Monthly schedule to run. Once: You can set the Time and Time Zone. You can also set the Date for the Once schedule to run
   Start date	Selection	Set schedule start date Cannot set a date earlier than the current date. The default is the current date.
   End date	Selection	Set schedule end date Cannot set a date earlier than the current date. The default is the current date plus 7 days.
   Permanent	Selection	When configuring permanently, set the schedule end date to 9999-12-31.
   time	Required	Schedule execution time setting Can be set in 30‑minute increments. Times earlier than the current date or current time cannot be set
   time zone	Required	Schedule execution time zone (example: Asia/Seoul (GMT +09:00))
   day of the week	Required	When Period is weekly, select the day of the week to run the schedule.
   Date	Required	When Period is set to Monthly, enter the Date on which the schedule will run Enter one or more values from -31 to 31, excluding 0. (Example: 3,4,5) When Period is set to Once, set the Date on which the schedule will run Cannot set a date earlier than the current date. The default is the current date.

   Table. Schedule edit popup items
6. Schedule Edit After entering the required values in the popup window, click the Confirm button.
7. Schedule Modification Confirmation After checking the message in the popup window, click the Confirm button.

Delete schedule

You can delete the schedule of an Auto-Scaling Group. To delete the schedule of an Auto-Scaling Group, follow these steps.

1. Click the All Services > Compute > Virtual Server menu. Navigate to the Service Home page of Virtual Server.
2. Click the Auto-Scaling Group menu. You will be taken to the Auto-Scaling Group List page.
3. On the Auto-Scaling Group List page, click the resource for which you want to view detailed information. You will be taken to the Auto-Scaling Group Details page.
4. Click the Schedule Tab. You will be taken to the Schedule Tab page.
5. Select the schedule to delete and click the Delete button. Schedule Deletion Confirmation popup will open.
6. Schedule Deletion Confirmation Check the popup window and click the Confirm button.

2.4 - Manage Notification

You can designate a notification recipient and send alert messages via E‑mail or SMS for specific situations.

Add notification

You can add notifications to an Auto-Scaling Group. To add notifications to an Auto-Scaling Group, follow these steps.

1. Click the All Services > Compute > Virtual Server menu. Navigate to the Service Home page of Virtual Server.
2. Click the Auto-Scaling Group menu. You will be taken to the Auto-Scaling Group List page.
3. On the Auto-Scaling Group List page, click the resource to which you want to add notification information. You will be taken to the Auto-Scaling Group Details page.
4. Click the Notification Tab. You will be taken to the Notification Tab page.
5. Click the Add Notification button. The Add Notification popup opens.
6. Add Notification After entering the required values in the popup window, click the Confirm button.

   Category	Detailed description
   Notification timing	Notification timing when an Auto-Scaling Group alert occurs Server creation, Server termination, Server creation failure, Server termination failure, When policy execution conditions are met Multiple selection allowed
   Notification recipient	User who will receive the notification when an alert occurs Click the Add Notification Recipient button to select a user Only Samsung Cloud Platform users can be selected as recipients

   Table. Notification items

7. Add Notification Confirmation After checking the message in the popup window, click the Confirm button.

Edit Notification

You can modify the notification settings of an Auto-Scaling Group. To modify the notification settings of an Auto-Scaling Group, follow these steps.

1. Click the All Services > Compute > Virtual Server menu. Navigate to the Service Home page of Virtual Server.
2. Click the Auto-Scaling Group menu. Navigate to the Auto-Scaling Group List page.
3. On the Auto-Scaling Group List page, click the resource to edit the notification information. You will be taken to the Auto-Scaling Group Details page.
4. Click the Notification Tab. You will be taken to the Notification Tab page.
5. In the notification list, click the More > Edit button for the notification you want to modify. The Edit Notification popup window will open.
6. Edit Notification After editing the notification information in the popup window, click the Confirm button.

   Category	Detailed description
   Notification timing	Notification timing when an Auto-Scaling Group alert occurs Server creation, Server termination, Server creation failure, Server termination failure, When policy execution conditions are met Multiple selection allowed

   Table. Notification edit items
7. Edit Notification Confirmation After checking the message in the popup window, click the Confirm button.

Delete Notification

You can delete notifications for an Auto-Scaling Group. To delete notifications for an Auto-Scaling Group, follow these steps.

1. Click the All Services > Compute > Virtual Server menu. Navigate to the Service Home page of Virtual Server.
2. Click the Auto-Scaling Group menu. You will be taken to the Auto-Scaling Group List page.
3. On the Auto-Scaling Group List page, click the resource to edit the notification information. You will be taken to the Auto-Scaling Group Details page.
4. Click the Notification Tab. You will be taken to the Notification Tab page.
5. In the notification list, select the notification you want to delete, then click the Delete button. The Delete Notification Confirmation popup will open.
6. Delete Notification Confirmation Review the popup window and click the Confirm button.

3 - API Reference

4 - CLI Reference

5 - Release Note

Virtual Server Auto-Scaling