Access domain names_Global Traffic Manager 3.0 - Alibaba Cloud DNS

Connect your domain to Global Traffic Manager (GTM) to enable smart scheduling, delivering global load balancing and automated switchover to maintain uninterrupted service.

Choose an access method

Connect a domain name in two ways: CNAME access and the service domain name access. Their comparisons are as follows.

Dimension	CNAME access method	Service domain access
How it works	Create an access domain name, such as `gtm.yourdomain.com`. Add a CNAME record on your service domain name, such as `www.example.com`, pointing to the access domain, for example, `www.example.com CNAME gtm.yourdomain.com`.	Create an access domain name, such as `gtm.yourdomain.com`, and use it as the service domain name for your clients.
Domain hosting	Requires an additional domain name or subdomain to host the GTM instance. The service domain name can be hosted on Alibaba Cloud DNS or by another DNS provider.	No extra domain needed. Configure the business domain that is hosted on Alibaba Cloud DNS directly.
Resolution performance	Involves one additional CNAME lookup, which is theoretically a few milliseconds more latency than direct management.	Optimal. No extra DNS queries are required, which provides the highest resolution performance.
Use cases	Existing online services that require high stability. When the domain name resolution service is not hosted on Alibaba Cloud DNS. Multiple service domains share the same set of IP addresses, such as `www.example.com` and `test.example.com`.	For new services that require maximum performance, or for root domain name access, such as `yourdomain.com`. When the service domain name is already hosted on Alibaba Cloud DNS.

Use case 1: Your domain name www.example.com is a live and stable, and you want to use GTM 3.0 for failover. In this case, choose the CNAME Access Method. Create an access domain name using another primary domain or subdomain, such as gtm.cloud-example.net. Once failover is validated, go to your DNS provider, modify the DNS records for www.example.com, and add a CNAME record that points to gtm.cloud-example.net.

Use case 2: For a new workload that pursues peak resolution, its domain name www.example.com is hosted on Alibaba Cloud DNS. In this case, set www.example.com as the GTM access domain. After configuring the address pools, addresses, and load balancing policies, you can enable the access domain name.

Create an access domain name

Prerequisites

If you choose subscription, create a GTM instance in advance. For more information, see Purchase a subscription instance. For pay-as-you-gp, creating a GTM instance is not required.
The domain that you want to use for the access domain name must be hosted on Alibaba Cloud DNS.
An access domain name consists of a host record and a primary or subdomain. The Primary/Subdomain is populated from the list of domain names managed by Alibaba Cloud DNS. Ensure that the correct DNS server addresses are configured for the Primary/Subdomain.

Steps

Go to the Alibaba Cloud DNS - Global Traffic Manager console and click Create Access Zone Name.
In the dialog box that appears, select Custom Scenario.
Move the pointer over the Access Zone Name icon. In the pop-up window, click Basic Configuration.

Configure the access domain name based on the table below.

Parameter	Description
Billing Method	Options: Subscription Pay-as-you-go
Bind Instance	If you set Billing Method to Subscription, you must bind an available subscription GTM instance. If you set Billing Method to Pay-as-you-go, the system automatically binds a GTM instance that cannot be changed.
Access Domain Name	Consists of `host record`.`primary or subdomain`. Host Record: The system generates a default host record. You can also customize it to another host record, or even a multi-level host record, such as `biz` or `prod.biz`. Primary/Subdomain: A primary domain name or subdomain hosted by the public zone.
Record Type	For address pools that require intelligent scheduling, the supported record types are A, AAAA, and CNAME; the corresponding pool types are IPv4, IPv6, and domain (hostname).
TTL	GTM provides traffic management services in the form of domain names. Global Time to Live (TTL) is the amount of time that the DNS record, which resolves the access domain name to an address, is cached on a carrier's local DNS server.
Enabled Status	The domain name is disabled by default. In this state, GTM policies do not take effect and no DNS resolution is provided. We recommend completing the configuration of address pools, addresses, and load‑balancing policies before enabling the instance. Important When GTM is enabled for `www.example.com`, and a record of the same type already exists in Alibaba Cloud DNS, DNS record will be overridden after you enable the GTM domain instance. GTM smart scheduling takes precedence.
Remarks	A user-defined identifier to help you recognize the application associated with the instance.

View the access domain name list

After you submit the access domain form, a record is added to the domain instance list. See the table below for key fields:

Field	Description	Example value
Access Domain Name/Instance ID	Access Domain Name: The full domain name that consists of `host record` and `domain name suffix`. Instance ID: After purchasing a GTM instance, the system automatically generates an instance ID, which is the unique identifier for the application and is used for upgrades, renewals, and releases.	`www.example.com`
Service Availability	The current availability status of the GTM instance. Valid values include the following: Available: Access domain is Enabled and health check is Normal. Unavailable: Access domain is Disabled, regardless of the health check status. Unavailable (Underlying Resolution Being Performed): Access domain is Enabled but the health status is Abnormal. GTM attempts failover to return an answer when possible. Important Failover resolution rules: If an address pool for a fine-grained line becomes unavailable, GTM responds with an address from the available address pool of global default line with the lowest sequence number. If no pools are unavailable, GTM selects the non-empty pool with the lowest sequence. Addresses are returned round-robin.	Available
Load Balancing Policy	The load balancing policies between address pools include Polling, Global Availability, Weighted, and Nearest Source. For more information, see Configure load balancing policies between address pools.	Polling
Edition	The billing type of the GTM instance. Types include the following: Subscription/Standard Edition, Subscription/Ultimate Edition, and Pay-as-you-go.	Pay-as-you-go
Enabled Status	The status of the access domain name. Valid values include Enabled or Disabled. When disabled, the smart scheduling policy for the GTM instance is unavailable.	Enabled
Health Status	The health status of the access domain name instance. The statuses including the following: Normal: All address pools referenced by the access domain name are available. Warning: Some of the address pools referenced by the access domain name are unavailable. In the Warning state, resolution for available address pools proceeds normally, while resolution for unavailable address pools is stopped. Abnormal: All address pools referenced by the access domain name are unavailable. In the Abnormal state, failover resolution is performed using an address from the first referenced non-empty address pool to provide a resolution result to the client whenever possible.	Normal

Enable an access domain name

Avoid enabling the access domain before configuring pools, addresses, and load‑balancing policies to avoid incorrect DNS resolution in production. Follow the steps below to enable it:

Go to the Alibaba Cloud DNS - Global Traffic Manager console and find the target access domain name.
Confirm that the access domain name is currently Disabled and that its health status is Normal.
If the domain name currently provides online services through public zone, confirm that the address pools, addresses, and load balancing policies are correct. Perform this change during off-peak hours.
Click the toggle in the Enabled Status column. In the prompt that appears, confirm the risks and click Enable.
After you enable the access domain name, if your service domain name (such as www.example.com) already has the same record type in Alibaba Cloud DNS, those records are overridden. The intelligent resolution configured in GTM takes precedence.

Disable or delete an access domain name

If you disable or delete an access domain name, GTM stops providing resolution for it. The original DNS record of the same type for that domain name in Alibaba Cloud DNS will be used for resolution again.

Go to the Alibaba Cloud DNS - Global Traffic Manager console and find the target access domain name.
Toggle the switch in the Enabled Status column. In the prompt that appears, confirm the risks to disable the access domain name.
In the Actions column, click Delete. In the prompt that appears, confirm the risks to delete the domain name.

Note

After you delete an access domain name, its resolution results may still be retrievable for a period. This occurs because local DNS servers of various network carriers cache DNS records. Until the cache expires, these local DNS servers return cached results to visitors instead of querying Alibaba Cloud DNS for the latest records. The change takes effect only after the local cache is refreshed. The time required for the change to take effect depends on the TTL of the cached DNS record, typcially 10 to 30 minutes.