:Global configurations

Overview

Global configurations indicate the basic configurations of a Global Traffic Manager (GTM) instance, including the instance name, canonical name (CNAME), primary domain name, load balancing policy, global time-to-live (TTL), and alert group.

Parameters or UI elements

1. Instance Name

The name of the GTM instance, which helps users identify the application services whose traffic is managed by the instance. An instance name must be informative and easy to remember. You can change the instance name on the Basic Settings tab.

2. CNAME

The domain name that is used to access the GTM instance. You need to add a CNAME record in Alibaba Cloud DNS to map the primary domain name to this domain name. You can use a public domain name within your account as the suffix of this domain name. The public domain name must be added to Alibaba Cloud DNS and be associated with a paid instance.

Note:

• If you use a custom domain name, you need to set the TTL of the custom domain name to 1 minute in the DNS settings of the domain name. Therefore, we recommend that you purchase Alibaba Cloud DNS Enterprise Standard Edition for the domain name.

• If the custom domain name does not use Alibaba Cloud DNS for resolution, you can migrate your DNS records to Alibaba Cloud DNS. Then, you can use the custom domain name to access the GTM instance.

• If you do not want to migrate DNS records to Alibaba Cloud DNS, you can manage subdomains in the Alibaba Cloud DNS console and add name server (NS) records to resolve the subdomain name. Then, specify the subdomain name as the suffix of the domain name for accessing the GTM instance.

• If you use a custom domain name, the specified DNS request sources must match the line type of the domain name in Alibaba Cloud DNS. For example, if you specify ISP as the line type of the domain name, you must select ISP or Global for the DNS Request Source parameter.

3. Load Balancing Policy

The load balancing policy of the GTM instance. Valid values: Load Balancing and Weighted Round-robin.

• Load Balancing: This is the default load balancing policy. If an address pool contains more than one IP address, access traffic from clients is evenly distributed to these IP addresses.

• Weighted Round-robin: If users of your application services are distributed across your country or region or around the world, you can select this policy to distribute network traffic based on the capacity of each IP address in the address pool. This policy allows the system to distribute access traffic based on weights. You can set a weight for each IP address. Alibaba Cloud DNS returns IP addresses based on the predefined weights. If you select this policy, you must edit the address pool on the Address Pools tab to add weights.

4. Global TTL Period

GTM provides traffic management services by using domain names. The global TTL specifies the TTL of the IP address information cached in the DNS system of an ISP. By default, the global TTL is set to 1 minute. If you use a custom domain name, the global TTL must be the same as the minimum TTL that is supported by the Alibaba Cloud DNS service plan of the custom domain name.

5. Primary Domain Name

The domain name that is used by users to access application services. Make sure that you specify a valid primary domain name.

Note: To implement traffic scheduling, you must use a CNAME record to map your primary domain name to the access domain name of your GTM instance in the Alibaba Cloud DNS console.

6. Alert Group

The group of contacts to which notifications are sent if errors occur. You can configure an alert group in CloudMonitor. If the health check feature of GTM detects an issue such as invalid IP address or address pool unavailability, GTM sends an alert notification to the specified alert group.

7. Modify

If you want to modify the global configurations of a GTM instance, you can click Modify on the Basic Settings tab. The parameters that you can modify include Instance Name, CNAME, Primary Domain Name, Load Balancing Policy, Global TTL Period, and Alert Group.

Procedure

1. Log on to the Alibaba Cloud DNS console.

2. In the left-side navigation pane, click Global Traffic Manager. On the Global Traffic Manager page, find the GTM instance that you want to manage and click the instance ID to go to the instance details page.

3. On the Basic Settings tab, click Modify.

4. In the Modify Instance panel, modify the following parameters: Instance Name, CNAME, Primary Domain Name, Load Balancing Policy, Global TTL Period, and Alert Group.

Note: If you set the load balancing policy to Weighted Round-robin, you must edit the address pool on the Address Pools tab to add weights.