When you use Gateway Load Balancer (GWLB) to distribute client requests, you must create a server group and add at least one backend server to receive requests forwarded by GWLB. You can also remove backend servers or delete server groups at any time. This topic describes how to create and manage server groups.
Prerequisites
Before you add backend servers to a server group, make sure that you have created the backend server instances, deployed a network virtual appliance (NVA) image, and confirmed that the backend servers can process Geneve protocol traffic to receive forwarded requests.
To route traffic to the backend servers in a server group, you must specify the server group when you create a listener. For more information, see Add and manage IP listeners.
Create a server group
Log on to the GWLB console.
In the top navigation bar, select the region where the GWLB instance is deployed.
In the left-side navigation pane, choose .
On the Server Group page, click Create Server Group.
In the Create Server Group dialog box, configure the following parameters and then click Create.
Parameter
Description
Server Group Type
Select a server group type:
Server: You can add Elastic Compute Service (ECS) instances, Elastic Network Interface (ENI) instances, or Elastic Container Instance (ECI) instances as backend servers.
IP: You can add IP addresses as backend servers.
Server Group Name
Enter a name for the server group.
VPC
From the drop-down list, select the Virtual Private Cloud (VPC) where the backend servers are deployed.
Backend Protocol
Only the Geneve protocol is supported.
Scheduling Algorithm
Select a scheduling algorithm:
5-tuple Hashing: Traffic is distributed based on the source IP address, source port, destination IP address, destination port, and transport protocol.
3-tuple Hashing: Traffic is distributed based on the source IP address, destination IP address, and transport protocol.
2-tuple Hashing: Traffic is distributed based on the source IP address and destination IP address.
By default, 5-tuple Hashing is selected.
Health Check Method
Select a health check protocol or disable health checks.
TCP (Default): Sends SYN packets to check whether the server port is active.
HTTP: Sends GET requests to simulate browser access and check whether the server application is healthy.
Disable Health Check: Health checks are not performed.
Health Check Port
Specify the port on the backend server to use for health checks.
Advanced Health Check Settings
Click Advanced Health Check Settings to configure additional settings. This option is available only if you enable health checks.
Health Check URL
Enter the URI of the health check page.
NoteThis parameter is available only when Health Check Method is set to HTTP.
Health Check Domain Name
Specify the domain name for health checks.
Backend Server Internal IP (Default): The private IP address of the backend server is used as the health check domain name.
Custom Domain Name: Enter a custom domain name for health checks.
NoteThis parameter is available only when Health Check Method is set to HTTP.
Health Check Status Codes
Select the HTTP status codes that indicate a successful health check.
http_2xx (Default)
http_3xx
http_4xx
http_5xx
NoteThis parameter is available only when Health Check Method is set to HTTP.
Health Check Timeout Period (Seconds)
The amount of time to wait for a response to a health check. If a backend server does not respond within this period, the health check fails.
Health Check Interval (Seconds)
The interval between consecutive health checks.
Healthy Threshold (Health Checks)
The number of consecutive successful health checks required to change a backend server's status from unhealthy to healthy.
Unhealthy Threshold (Health Checks)
The number of consecutive failed health checks required to change a backend server's status from healthy to unhealthy.
Connection Draining
When enabled, connection draining allows existing traffic to continue flowing to a backend server that is being deregistered or has become unhealthy, until a timeout is reached. This feature is disabled by default.
If you enable connection draining, you must set the Connection Draining Timeout Period (Seconds). The value must be between 1 and 3,600. A value of 0 indicates that connections are terminated immediately.
Tags and Resource Group
Expand the Tags and Resource Group section and configure the following parameters:
Set a Tag Key and Tag Value.
Resource Group: Select the resource group to which the server group belongs.
Add backend servers
After you create a server group, you must add backend servers to it to handle incoming traffic.
Server type
When you create a server group of the server type, you need to add Elastic Compute Service (ECS) instances, Elastic Network Interfaces (ENIs), or Elastic Container Instances (ECIs) as backend servers.
Log on to the GWLB console.
In the top navigation bar, select the region where the GWLB instance is deployed.
In the left-side navigation pane, choose , and then click the ID of the target server group.
On the Backend Servers tab, click Add Backend Server.
In the Add Backend Server panel, select a server type.
ECS instances
Select ECS/ENI as the server type and select the target servers.
If no ECS instances are available, click Purchase ECS Instance in the upper-right corner of the server list.
ENIs
Select ECS/ENI as the server type and enable Advanced Mode.
Click the plus sign (+) next to the ID of the target ECS instance and select an ENI.
To select an ENI, make sure that a secondary ENI is attached to the target ECS instance. For more information, see Attach a secondary ENI.
If no ECS instances are available, click Purchase ECS Instance in the upper-right corner of the server list.
ECI instances
Select ECI as the server type and select the target servers.
If no ECI instances are available, click Purchase Elastic Container Instance in the upper-right corner of the server list.
Click OK.
IP type
When the server group is of the IP type, you need to add IP addresses as backend servers.
Log on to the GWLB console.
In the top navigation bar, select the region where the GWLB instance is deployed.
In the left-side navigation pane, choose , and then click the ID of the target server group.
On the Backend Servers tab, click Add IP.
In the Add Backend Server panel, enter the IP addresses of the backend servers.
NoteTo add multiple backend servers, click Add IP.
You can enter private IP addresses from the following CIDR blocks:
10.0.0.0/8
100.64.0.0/10
172.16.0.0/12
192.168.0.0/16
Click OK.
Other operations
Actions | Procedure |
Update a server group |
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Remove a backend server |
Note Removing a backend server does not terminate the instance. You can add it back to the server group at a later time. |
Delete a server group |
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