To associate a listener with an endpoint group, you need to specify the region to which you want to route network traffic. Then, the system routes network traffic to the endpoint in the endpoint group based on the routing type of the listener.
Endpoint groups
Each endpoint group is associated with a region. You can associate an endpoint group with a listener by specifying the region to which you want to distribute network traffic. After you associate an endpoint group with a listener, the system forwards client requests to endpoints in the endpoint group based on the routing type of the listener.
By default, you can create two endpoint groups for a custom routing listener.
Intelligent routing listeners support the following types of endpoint groups:
Default endpoint group: the endpoint group that you configured when you create a listener.
By default, you can create two default endpoint groups for a TCP or UDP listener. If you want to create additional endpoint groups, go to the Quota Management page and increase the quota named gaplus_quota_epgs_per_listener. For more information, see Manage GA quotas.
A default endpoint group can be deployed in only one region. You can specify a traffic distribution ratio for each endpoint group. The traffic distribution ratio specifies the proportion of traffic that is distributed to an endpoint group. For more information about how to specify traffic distribution ratios, see Distribute traffic across endpoint groups in different scenarios.
You can create one default endpoint group for each HTTP or HTTPS listener.
Virtual endpoint group: After you create a listener, you can create a virtual endpoint group on the Endpoint Groups page.
By default, you can create up to 10 virtual endpoint groups for each listener regardless of the listener protocol. If you want to create additional virtual endpoint groups, go to the Quota Management page and increase the quota named gaplus_quota_vepg_per_listener. For more information, see Manage GA quotas.
After you create a virtual endpoint group for a listener, you can create a custom forwarding rule and associate the rule with the virtual endpoint group. After you associate a forwarding rule with an endpoint group, the listener forwards the requests that meet the forwarding conditions to the default endpoint group or the virtual endpoint group specified in the forwarding rule. This way, GA can access multiple endpoints at the same time. For more information about how to create a forwarding rule, see Add and manage forwarding rules.
NoteIf you cannot add virtual endpoint groups to or configure forwarding rules for the TCP or UDP listener of your standard GA instance, the instance may be using an earlier version. Contact your account manager to upgrade your GA instance.
Endpoints
Endpoint types
Endpoints are the destinations of client requests. You can add up to four endpoints to an endpoint group. The following table describes the types of endpoints.
Endpoint deployment | Connection type | Endpoint type | Endpoint |
Alibaba Cloud | Internet connection | Alibaba Cloud public IP address |
|
CLB | Internet-facing CLB instances | ||
Private connection | ECS | ECS instances in virtual private clouds (VPCs) | |
ENI | Elastic network interfaces (ENIs) | ||
CLB | Internal-facing CLB instances in VPCs | ||
ALB | Application Load Balancer (ALB) instances | ||
NLB | Network Load Balancer (NLB) instances | ||
OSS | Object Storage Service (OSS) buckets | ||
vSwitch Only custom routing listeners support this type. | vSwitches You can specify the private IP addresses and destination ports of one or more ECS instances in the vSwitch to which you want to forward traffic. | ||
Outside Alibaba Cloud | Internet connection | Custom IP address | Custom IP addresses of origin servers |
Custom domain name | Custom domain names of origin servers |
If your standard GA instance does not support ALB instances, ECS instances in VPCs, CLB instances in VPCs, NLB instances, or ENIs as endpoints, the GA instance may be using an earlier version. Contact your account manager to upgrade your GA instance.
Custom routing listeners are in invitational preview. To use custom routing listeners, submit an application to your account manager. After your application is approved, you can use custom routing listeners.
Custom routing listeners allow you to specify an IP address and a port in a vSwitch to which you want to forward traffic. You can specify only the IP address and port of an ECS instance.
The endpoint group IP addresses of a GA instance are unique and are not shared with other GA instances.
Weights of endpoints
You can specify a weight for an endpoint. The weight specifies the proportion of traffic that is forwarded to the endpoint. GA calculates the sum of all endpoint weights in an endpoint group. Then, traffic is forwarded to each endpoint based on the proportion of each endpoint. For more information, see Specify the weight of an endpoint.
Custom routing listeners can forward client requests to a specific IP address and port in a vSwitch. You do not need to specify weights for endpoints.
Health checks
You can enable health checks for endpoint groups of a GA instance. This improves service reliability and availability and prevents service interruptions caused by unhealthy endpoints.
After you enable health checks for an endpoint group, GA periodically checks whether the endpoints are healthy. When GA detects an unhealthy endpoint, GA distributes requests to healthy endpoints. When the unhealthy endpoint recovers, GA distributes requests to the endpoint again. For more information, see Enable and manage health checks.
You can enable health checks only for endpoint groups of standard GA instances that use intelligent routing listeners.