Create and manage target group

Creating and managing target groups, including listing, modifying information, and setting up Listener connections, is as follows:

Create target group

1. Go to KakaoCloud Console > Beyond Networking Service > Load Balancing > Target Group..

2. Click the [Create target group] button in the upper right corner.

3. In the Step 1: Configure target group screen, enter the settings and click the [Next] button.

   Step 1: create target group

   Category	Item	Description
   Load balancer	Availability Zone	Choose from available AZs in the project
   	Load balancer	List of all load balancers in the selected availability zone
   	Listener	List of all Listeners for the selected load balancer and option to select 'None'
   Basic information	Target group name	Allowed characters: English uppercase and lowercase letters, numbers, special characters -, _ (Length: 4-250 characters) - Must start with a letter - Special characters are not allowed at the start or end - Consecutive special characters are not allowed
   	Protocol	Target group protocol options depending on listener protocol - TCP Listener: HTTP, HTTPS, TCP, PROXY - UDP Listener: UDP - TLS Listener: TCP
   	Algorithm	Choose between Round Robin, Least connections, Source IP Hash - Round Robin: Distributes traffic sequentially to Targets within the target group - Least connections: Distributes traffic preferentially to Targets with fewer connections - Source IP Hash: Ensures that clients with the same IP header always send traffic to the same target
   	Sticky session	Can only be enabled/disabled when Listener x target group combination is as follows (TLS Listener is not supported) - HTTP x HTTP, TCP x TCP, UDP x UDP - Otherwise: 'Disabled' (inactive)
   	Sticky session type	Types available for Listener x target group combination - HTTP x HTTP: HTTP Cookie, App Cookie - TCP x TCP: Source IP - UDP x UDP: Source IP
   	Stickiness duration	Activated only when using sticky sessions (HTTP Cookie, App Cookie) - Integer between 1 and 604800 (default: 3600 seconds for HTTP Cookie, otherwise 360 seconds)
   	Cookie name	Activated only when using sticky sessions (App Cookie) - The Cookie name used by the user's application must be entered - Allowed characters: English uppercase and lowercase letters/numbers/some special characters (! # $ % ^ & _ * + ~ - ) - Allowed length: 1-255 characters
   	Sticky IP-netmask	Activated only when using sticky sessions (Source IP) - Input in IPv4 address format only (default: 255.255.255.255)
   Health Check	Health Check	Enable or disable
   	Type	Types available depending on target group protocol - HTTP target group: HTTP, PING - HTTPS target group: HTTPS, PING - TCP target group: PING, TCP - UDP target group: TCP, HTTP - PROXY target group: PING, TCP
   	HTTP method	- Set only when HTTP is selected as the Health Check type - Choose from CONNECT, DELETE, GET, HEAD, OPTIONS, PATCH, POST, PUT, TRACE
   	HTTP version	- Set only when HTTP is selected as the Health Check type - Choose between 1 or 1.1
   	HTTP status code	- Set only when HTTP is selected as the Health Check type - Enter a single code, multiple codes separated by commas, or a range of codes specified by hyphens (-)
   	Check path	Input in URL format
   	Check interval	Integer between 1 and 3600 (default: 30 seconds). Must be larger than timeout
   	Timeout	Integer between 1 and 900 (default: 5 seconds). Must be smaller than check interval
   	Transition criteria (success)	Integer between 1 and 10 (default: 5 times)
   	Transition criteria (failure)	Integer between 1 and 10 (default: 2 times)

   info

   If the algorithm is Source IP Hash, traffic from a single source is always delivered to the same target. Therefore, there is no need to configure sticky session, and this feature is disabled. If you want to maintain sticky sessions, it is recommended to use Source IP Hash.

4. In the Step 2: Add targets screen, you can add resources that are in the same AZ and VPC as the selected load balancer in Step 1.

5. Select the instances to add as targets and enter the port numbers.

6. Click the [Add target] button.

   • Added Target > Target Filter: IP, Port, Instance Name, Instance ID, Status

7. You can add the same target with a different port number or remove added targets.

8. Once target addition is complete, click the [Next] button.

9. In the Step 3: Review screen, check the information and click the [Create] button.

info

• After creating a target group, it is necessary to configure the security group of the targets.
  
• In the Target Group > Target tab, check the Health Check IP address and add this IP address to the inbound rules of the target's security group.

Manage target group

You can modify or delete existing target groups or add new targets from the target group details screen.

View target group list

1. Go to KakaoCloud Console > Beyond Networking Service > Load Balancing > Target Group..

2. Check the list of target groups. If needed, you can easily search for the desired target group using filters.

   • Filters: target group Name, target group ID, Provisioning status, Operating status, Protocol, Load balancer name, load balancer ID, VPC Name, VPC ID

   Category	Description
   Target group name	Displays the name entered during creation and the assigned ID
   Provisioning status	Information on whether the target group has been successfully created or if modifications or deletions are in progress
   Operating status	Information on whether the created target group is available
   Protocol	Protocol used for routing traffic to Targets
   Load balancer	Name and ID of the load balancer connected to the target group
   VPC	Name and ID of the VPC containing the load balancer
   [More] icon	Provides options for renaming, setting Listener connections, algorithm settings, Target settings, traffic weight settings, health check settings, sticky session settings, and deletion

View target group details

1. Go to KakaoCloud Console > Beyond Networking Service > Load Balancing > Target Group..

2. Select the target group to view details.

3. Check detailed information, Targets, Health Check, and Properties in each tab of the detail screen.

   Category	Description
   Details	View detailed information of the target group
   Targets	View the list of added targets and detailed information of each target
   Health Check	View health check settings
   Attributes	View properties of the target group

Rename target group

1. Go to KakaoCloud Console > Beyond Networking Service > Load Balancing > Target Group..

2. Select the target group to rename and click the [More] icon > Rename option.

3. Enter the new name and click the [OK] button.

Configure listener connection

1. Go to KakaoCloud Console > Beyond Networking Service > Load Balancing > Target Group..

2. Click on the [More] icon > select Configure listener connection.

3. In the popup window, modify the listener connection settings and click the [Apply] button.

   • When configuring Listener connections: You can select from the list of available Listeners and connect to more than one Listener.
   • When not connecting to a Listener: Disconnects from the listener.

   Configure listener connection

Set algorithm

1. Go to KakaoCloud Console > Beyond Networking Service > Load Balancing > Target Group..

2. Select the [More] icon amd [Set algorithm].

3. In the popup, change the algorithm and click the [Apply] button.

Configure target

1. Go to KakaoCloud Console > Beyond Networking Service > Load Balancing > Target Group..

2. Select the target group to change the target settings.

3. In the detail screen, click the Target tab and then click the [Configure target] button.

4. In the popup, check the registered targets, delete or add targets, and click the [Apply] button.

Set traffic weight

1. Go to KakaoCloud Console > Beyond Networking Service > Load Balancing > Target Group..

2. Select the target group to change the traffic weight settings.

3. Click the Target tab and then click the [Set traffic weight] button.

4. In the popup window, change the weight and click the [Set] button.

   • Traffic weight can be entered as an integer between 0 and 256.
   • Weight is converted to a weight conversion value using the formula:
     • Weight Conversion: (Weight / 256) * 100 (rounded up to the nearest tenth)
     • Ratio: Weight Conversion / Sum of Weight Conversions

Set health check

1. Go to KakaoCloud Console > Beyond Networking Service > Load Balancing > Target Group..

2. Select the target group to change the health check settings.

3. Click the Health Check tab and then click the [health check settings] button.

4. In the popup, change the Health Check usage or settings.

   Type	Description
   Target group	Current target group name
   Protocol	Types available depending on the target group's protocol - HTTP target group: HTTP, PING - HTTPS target group: HTTPS, PING - TCP target group: PING, TCP - UDP target group: TCP, HTTP - PROXY target group: PING, TCP
   Health Check Usage	Type: Type of Health Check - PING: Sends packets to the target and checks the response (ICMP Ping) - HTTP: Sends packets to the configured path and checks the response - HTTPS: Checks response similarly to HTTP but with a certificate - TCP: Checks the status of the target using TCP Protocol port
   	Check Interval: Interval for Health Check (in seconds) - 1~3600 seconds
   	Timeout: Maximum wait time for a delayed response (in seconds) - Considered a failure if it exceeds the specified time - Should be set smaller than the check interval - 1~900 seconds
   	State Transition Criteria (Success): Considered normal if Health Check is successful consecutively for the specified number of attempts
   	State Transition Criteria (Failure): Considered abnormal and excluded from traffic distribution if Health Check fails consecutively for the specified number of attempts

5. If the Health Check type is HTTP or HTTPS, additional attributes can be set.

   Type	Description
   HTTP method	Choose from GET, HEAD, OPTIONS, POST, PUT, TRACE, PATCH, DELETE, CONNECT
   HTTP version	Choose from 1.0 or 1.1
   HTTP status code	Set the expected status codes for the target to respond with - If the target responds with the configured HTTP status code, it is considered a successful Health Check - Example of single status code: 200, 201 - Example of multiple status codes: 201, 202, 401, 402 - Example of range: 200-500
   Check path	Enter the URL Path for performing Health Check

6. Click the [Apply] button.

info

If the target in the target group uses SELinux options provided by the latest CentOS distributions like CentOS 8 Stream, SELinux may deny shell_exec_t calls. Therefore, PING type Health Check will not work.

Set sticky session

Sticky Sessions can be configured for some target groups depending on the Listener and target group protocol.

Sticky session options by listener and target group protocol

Target group\Listener	HTTP	HTTPS	TCP	UDP
HTTP	HTTP Cookie, App Cookie	X	X	X
HTTPS	X	X	X	X
TCP	X	X	Source IP	X
UDP	X	X	X	Source IP
PROXY	X	X	X	X

1. Go to KakaoCloud Console > Beyond Networking Service > Load Balancing > Target Group..

2. Click on the target group to configure sticky sessions.

3. Click the Properties tab and then click the [Configure sticky session] button.

4. In the popup window, change the usage or settings and click the [Apply] button.

Delete target group

1. Go to KakaoCloud Console > Beyond Networking Service > Load Balancing > Target Group..

2. Click on the [More] icon for the target group to delete.

3. Select Delete target group from the [More] icon.

4. In the popup, enter the confirmation text and click the [Delete] button.

Manage target

You can view, modify, and delete targets added to the target group.

caution

Two health check IPs are created for each subnet where the targets are located. To perform Health Check, you must allow communication through these IPs.
Please refer to View health check IP and Allow communication for health check IP documents to add inbound rules to your security group.

View health check IP

1. Go to KakaoCloud Console > Beyond Networking Service > Load Balancing > Target Group..

2. Select the target group to view health check IPs.

3. In the detailed view, select the Target tab.

4. Click on Health check IP per subnet at the top of the tab to view the list of health check IPs.

Allow communication for health check IP

There are two methods to configure security group settings to allow communication for health check IPs.

Method 1: Register inbound policies for the existing security group of the target instances

1. Go to KakaoCloud Console > Beyond Networking Service > Load Balancing > Target Group..

2. Select the target group to retrieve and allow communication for health check IPs.

3. In the detailed view, select the Target tab.

4. Click on Health check IP per subnet and copy the list.

5. In the Target List section, identify the instances that need to allow communication for health check IPs, and click the security group name associated with those instances.

   • If multiple security groups are connected, select one randomly for registration.
   • If one or more of the connected security groups already have the same policy, communication is already allowed.

6. Click the [Manage inbound rules] button in the Inbound rules tab.

7. In the popup, click the [Add] button at the bottom of the Inbound Policies tab to add a new policy.

8. Based on the detailed information from Step 5, enter the policy information and click the [Apply] button on the right.

   Type	Description
   Protocol	Protocol for communication (TCP, UDP, ICMP, ALL) depending on the target group's Health Check type - For Health Check type PING: ICMP - For Health Check types HTTP, HTTPS, TCP: TCP
   Source	Source IP to allow access - Enter Health Check IP identified from the target details - Register each of the two health check IPs generated in the subnet
   Port	Port for communication - Enter the monitoring port of the target
   Policy description (Optional)	Description of the policy

9. Click the [Close] button at the bottom of the popup to complete the policy registration.

Method 2: Create a new security group for health check and connect to target instances

1. Go to KakaoCloud Console > Beyond Networking Service > Load Balancing > Target Group..

2. Select the target group to retrieve and allow communication for health check IPs.

3. In the detailed view, select the Target tab.

4. Click on Health check IP per subnet at the top of the tab to view the list of health check IPs.
   Keep this view open or copy the list.

5. Refer to Create security group to enter the screen for creating a new security group.

6. In the popup, enter the name and description for the security group, and add inbound policies.

7. Based on the detailed information from Step 4, enter the policy information:

   • Register all health check IPs in one security group and connect this security group to all target instances.
     Alternatively, create a security group per subnet, registering only the health check IPs generated in that subnet, and connect only the target instances in that subnet.

   Type	Description
   Protocol	Choose the protocol for communication (TCP, UDP, ICMP, ALL) based on the target group's Health Check type. - For Health Check type PING: ICMP - For Health Check types HTTP, HTTPS, TCP: TCP
   Source IP	Enter the health check IPs identified from the target details. - Register each of the two health check IPs generated in the subnet. - If managing with one security group, register each of the health check IPs.
   Port	Enter the port for communication. - Enter the monitoring port of the target. - Can be a single port or a range.
   Policy description (Optional)	Description of the policy.

8. Click the [Create] button to complete the security group creation.

9. In the security group list, click the [Manage Connected Resources] button next to the created security group to connect it to the target instances and complete the setup.

   • For details on managing connected resources, refer to Manage Connected Resources.

View target

1. Go to KakaoCloud Console > Beyond Networking Service > Load Balancing > Target Group..

2. Click on the target group to view targets.

3. In the detailed view, select the Target tab.

4. Review the list of targets added to the target group. Use filters if needed to easily search for specific targets.

   Type	Description
   IP	Target IP
   Port	Target Port
   Instance	Name and ID of the target instance
   Subnet	Name of the subnet containing the target
   Security Group	Security groups associated with the target instance
   Monitoring Port	Port used for Health Check
   Weight Ratio	Weight ratio calculated from the input weight
   Provisioning status	Information on whether the target has been successfully added or if changes are in progress
   Operating status	Information on whether the added target is in an operational state
   [More] icon	Provides options to configure monitoring port settings and disconnect targets

Modify target

info

The port of an added target cannot be modified. To change the port, delete the target and add it again..

Set monitoring port

1. Go to KakaoCloud Console > Beyond Networking Service > Load Balancing > Target Group..

2. Select the target group to modify targets.

3. In the detailed view, select the Target tab.

4. Review the list of targets added to the target group.

5. Click the [More] icon and Set monitoring port.

6. In the popup, modify the settings and click the [Apply] button.

Detach target

1. Go to KakaoCloud Console > Beyond Networking Service > Load Balancing > Target Group..

2. On the Target Group tab click a target group.

3. In the detailed view, select the Target tab.

4. Review the list of targets added to the target group.

5. Click the [More] icon > [Detach target].

6. In the popup, enter the confirmation text and click the [Detach] button.

info

Detaching a target does not delete the instance. To reconnect it, delete the target and add it again..