What are basic settings?
Basic settings are the parameters that you must specify for a Global Traffic Manager (GTM) instance. These settings include Instance Name, CNAME(Internet), Business Domain Name(Internet), Global TTL Period, Alert Group, and Notification Methods.
Procedure
Log on to the Alibaba Cloud DNS console.
In the left-side navigation pane, click Global Traffic Manager. On the Global Traffic Manager page, find the desired GTM instance and click Settings in the Actions column. The Basic Settings page appears.
On the Basic Settings page, click Modify.
In the Modify Basic Settings panel, specify the following parameters: Instance Name, CNAME(Internet), Business Domain Name(Internet), Global TTL Period, Alert Group, and Notification Methods.
Parameters
1. Instance Name
An instance name is used to identify an application service. Each instance name must be informative and easy to remember. To modify an instance name, go to the Basic Settings page.
2. Business Domain Name(Internet)
A service domain name is used to access an application service. This parameter is optional.
To implement traffic scheduling, you must add a canonical name (CNAME) record in the Alibaba Cloud DNS console to map a service domain name to a CNAME provided by GTM.
3. CNAME(Internet)
A CNAME is used to access GTM. On the DNS Settings page, you can add a CNAME record to map a service domain name to a CNAME. To set a custom CNAME, you must select a public domain name within your account as the suffix of the CNAME. The domain name must have been added in the Alibaba Cloud DNS console.
1. The minimum value of the Global TTL Period parameter is subject to the minimum TTL period supported by the edition of Alibaba Cloud DNS instance. The instance is associated with the suffix of the custom CNAME. We recommend that you associate the suffix of the CNAME to an Alibaba Cloud DNS instance of Standard Edition or Ultimate Edition. In this way, you can also use GTM to configure intelligent Domain Name System (DNS) resolution lines based on regions or Internet service providers (ISPs). If you do not host your domain names on Alibaba Cloud DNS, you can add a domain name.
2. If the DNS resolution service that you use is not provided by Alibaba Cloud, you can migrate DNS records to Alibaba Cloud.
3. If you do not want to migrate DNS records to Alibaba Cloud, you can host the subdomain name 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 CNAME for the GTM instance.
4. When you configure an access policy for the GTM instance, the value of the DNS Request Source parameter must be the same as the value of the ISP Line parameter. For example, if ISP is selected in the ISP Line field, the access policy for the GTM instance does not take effect if you select regional lines as the DNS request sources.
4. Global TTL Period
You can use GTM to manage network traffic based on domain names. The value of the Global TTL Period parameter specifies the TTL of the IP address information cached in the DNS servers of ISPs. Standard Edition supports a minimum TTL period of 1 minute. Ultimate Edition supports a minimum TTL period of 1 second.
The value of the Global TTL Period is limited by the minimum TTL period supported by the edition of the Alibaba Cloud DNS instance associated with the suffix of the custom CNAME and the GTM instance edition. The larger value is adopted.
For example, GTM Ultimate Edition supports a minimum TTL period of 1 second, and the edition of the Alibaba Cloud DNS instance associated with the suffix of the CNAME supports a minimum TTL period of 60 seconds. In this case, you can set the Global TTL Period parameter to 1 Minute.
For example, GTM Standard Edition supports a minimum TTL period of 60 seconds, and the edition of the Alibaba Cloud DNS instance associated with the suffix of the CNAME supports a minimum TTL period of 1 second. In this case, you can set the Global TTL Period parameter to 1 Minute.
5. Alert Group
An alert contact group is used to receive notifications if errors occur. You can configure an alert group in CloudMonitor. For more information, see Create an alert contact or alert contact group. If the health check feature of GTM detects an exception, for example, an IP address is abnormal or an address pool is unavailable, GTM sends an alert notification to the corresponding contact group.
To meet your business requirements for custom alert content and methods, GTM allows you to configure contact alert notification methods.
6. Modify
You can click Modify on the Basic Settings page to modify the following parameters of a GTM instance: Instance Name, CNAME(Internet), Business Domain Name(Internet), Global TTL Period, and Alert Group.