What are address pool configurations?
Global Traffic Manager (GTM) allows you to manage the addresses of application services by using address pools. An address pool contains a group of IP addresses or domain names that are used to access the same application service. The IP addresses or domain names belong to the same carrier or region. You can configure more than one address pool for a GTM instance. This way, requests from different regions can be forwarded to the nearest access points by using different address pools. If the primary address pool set to which the address pools belong is unavailable, you can switch to the secondary address pool set. Address pool configurations include the address pool name, address pool type, load balancing policy, address, region to which the address belongs, and address working mode.
1 . Add an address pool
You can add an address pool and then configure the address pool. The configurations include the address pool name, address pool type, load balancing policy, address, region to which the address belongs, and address working mode.
If you use GTM Standard Edition, you can add up to 10 address pools.
If you use GTM Ultimate Edition, you can add up to 20 address pools.
2 . Address pool name
Enter an address pool name that is easy to remember and identify, for example, Telecom address pool 01. When you configure access policies, you can identify address pools based on their names.
3 . Address pool type
The following address pool types are supported: IPv4, IPv6, and Domain Name.
Common address pool types are IP addresses. However, domain names are required for the services such as Alibaba Cloud CDN, Anti-DDoS, and Cloud Firewall. If an address pool contains multiple domain names, you can set the load balancing policy only to Return addresses by weight.
4 . Load balancing policy
The following types of load balancing policies are available: Return all addresses and Return addresses by weight.
If you select Return addresses by weight, you can set a weight after you add an IP address to the address pool.
Address weight: You can set different weights for IP addresses so that access traffic is distributed to each IP address based on the weight.
5 . Address
Enter an address based on the address pool type. If you use IP addresses, enter the IP address of your application service. If you use domain names, enter the domain name of your application service.
6 . Region to which the address belongs
After you specify an address in the address pool, GTM automatically displays the geographical location of the application service. You can also click Modify to modify the geographical location of the application service.
If the Address Pool Type parameter is set to Domain Name, you must modify the location.
7 . Address working mode
After you specify an address, you can set a working mode for the address. The following working modes are available:
Smart Return: This mode is used by default. GTM determines whether to return an IP address based on the health check result. If the IP address is available, DNS returns the IP address to clients. If the IP address is unavailable, GTM deletes the IP address.
Always Online: In this mode, GTM determines that an address is always available and DNS always returns the address to clients. The health check feature does not check the address.
Always Offline: In this mode, GTM determines that an address is always unavailable and DNS does not return the address to clients. This address is configured in the system settings for future use. The health check feature does not check the address.
8 . Add one or more addresses
You can add one or more addresses.
9 . Modify an address pool
You can modify an existing address pool. You can modify the configurations including the address pool name, address pool type, load balancing policy, address, region to which the address belongs, and address working mode.
10 . Delete an address pool
You can delete an existing address pool. If the address pool is associated with access policies, you must delete the access policies before you can delete the address pool.
11 . Health check
If you enable this feature, you can monitor the availability of your application service in real time. Available health check options include ping, tcp, and http(s). For more information, see Health check.
1 . Log on to the Alibaba Cloud DNS console.
2 . In the left-side navigation pane, click Global Traffic Manager. On the GTM Instances page, click the instance name. On the global configurations page, click the Address Pool Configurations tab. Then, click Add Address Pool.
3 . In the Add Address Pool pane, specify the address pool name, address pool type, load balancing policy, address, region to which the address belongs, address weight, and address working mode. Then, click OK.
4 . After you add the address pool, you can view the address pool configurations on the current page.
1 . A maximum of 10 address pools can be created for a GTM Standard Edition instance. A maximum of 20 address pools can be created for a GTM Ultimate Edition instance.
2 . A maximum of 20 addresses can be added to each address pool.
3 . To set weights for addresses in an address pool, you must set the load balancing policy to Return addresses by weight when you configure a GTM instance.
4 . If the health check feature is not enabled, the availability of an address pool availability is indicated by the address working mode. The Smart Return or Always Online mode indicates that the address pool is available. The Always Offline mode indicates that the address pool is unavailable.
5 . The address pools to which access policies apply cannot be directly deleted. You must modify or delete the access policies on the Access Policy Configurations page, and then delete the address pools on the Address Pool Configurations page.