Alibaba Cloud DNS:Basic configuration

Overview

The basic configuration for a Global Traffic Management (GTM) instance includes settings such as Instance Name, CNAME access domain, business domain, global TTL, alert notification group, and alert notification method.

Procedure

1. Go to the Cloud DNS-Global Traffic Management console.

2. On the Global Traffic Management instance list page, find the instance that you want to manage. In the Actions column, click Configure to go to the Basic Configuration page.

3. On the Basic Configuration tab, click Edit. The Modify Basic Configuration dialog box opens on the right.

4. In the Modify Basic Configurationdialog box, you can edit the Instance Name, CNAME access domain, business domain, global TTL, alert notification group, and alert notification method.

   For CNAME Access Domain Type, select Public. In the CNAME Access Domain Configuration section, you can select Custom access domain and configure the domain prefix and its associated domain name. Select a value, such as 10 minutes, from the Global TTL drop-down list. In the Alert Notification Group section, select up to five contacts. In the Alert Notification Method section, select Email, Webhook notification, or SMS for different event types, such as Address unavailable, Address restored, Address pool group unavailable, Address pool group restored, Failover between primary and secondary address pool groups, or Monitoring node IP address changed. Then, click OK.

Parameters

1. Instance name

   An instance name is a user-defined identifier for a GTM instance. It helps you easily recognize and manage the instance. You can edit the instance name on the Basic Configuration tab.

2. Business domain

   The business domain is the domain name that users use to access your application services. This parameter is optional.

   Important

   To enable traffic scheduling, you must add a CNAME record in Cloud DNS that points your business domain to the CNAME access domain provided by GTM.

3. Custom access domain

   This CNAME domain directs traffic to GTM. You must create a CNAME record in your DNS settings to point your business domain to this access domain. To set up a custom CNAME access domain, you must select a public domain that is already managed by Cloud DNS under your account. This domain will be used as the suffix for the access domain.

   
   Important

   1. If your domain's DNS is not hosted by Alibaba Cloud, you can migrate your domain resolution to Alibaba Cloud.

   2. If you cannot migrate your domain to Alibaba Cloud, you can use independent subdomain hosting. This method lets you delegate a subdomain to Cloud DNS by using NS records and then generate a custom CNAME access domain.

      For example, if the hosted subdomain is www.example.com and the access domain prefix is gtm, the custom access domain is gtm.www.example.com.

   3. The minimum global TTL is limited by the minimum TTL value allowed by the Cloud DNS edition of your custom CNAME access domain. We recommend that you attach the CNAME access domain to a Cloud DNS Standard or Ultimate Edition instance.

   4. For the source of DNS requests, you can select either ISP or Chinese mainland, but not both.

   Note

   • Based on your access policy and health check status, Cloud DNS automatically adds DNS records that resolve your custom domain to the active IP addresses to the Domain Names list.

   • In GTM 3.0, DNS records are no longer generated. The console provides a graphical interface that shows which policies are in effect.

4. Global TTL

   GTM provides traffic management as a DNS-based service. The global TTL (Time-to-Live) specifies how long DNS responses from GTM are cached by carrier DNS servers. The Standard Edition supports a minimum TTL of 1 minute, and the Ultimate Edition supports a minimum TTL of 1 second.

   Important

   The effective minimum global TTL is determined by both your GTM and Cloud DNS editions. It is set to the higher of the two minimum TTL values:

   • For example, if your GTM instance is Ultimate Edition (minimum TTL of 1 second) but the Cloud DNS edition for your custom domain's suffix supports a minimum TTL of 60 seconds, the effective minimum global TTL for your GTM instance is 60 seconds.

   • For example, if your GTM instance is Standard Edition (minimum TTL of 60 seconds) and the Cloud DNS edition for your custom domain's suffix supports a minimum TTL of 1 second, the effective minimum global TTL for your GTM instance is 60 seconds.

5. Alert notification group

   An alert notification group is a set of contacts that receives notifications when an issue occurs. GTM reads the alert notification groups that you configure in CloudMonitor. For more information, see Create an alert contact or contact group. If a GTM health check detects an issue, such as an unavailable IP address or an unavailable address pool, GTM sends a notification to the specified contacts.

   Note

   GTM allows you to customize alert content and delivery methods through the alert notification method settings.

6. Modify

   The Edit action allows you to edit the basic configuration of a GTM instance after its initial setup. Settings that can be changed include Instance Name, CNAME access domain, business domain, global TTL, and alert notification group.