What are instances?
On the Global Traffic Manager page of the Global Traffic Manager (GTM) console, you can view the details of instances. These details include the instance ID, CNAME access domain name, number of health check tasks, number of notifications, status, instance package version, expiration time, and actions.
GTM allows you to manage the access traffic of your application services in a fine-grained manner. GTM manages different application services by using instances. Each instance corresponds to an application service. For example, Instance 1 is used to manage the traffic of the www.dns-example.com service. Instance 2 is used to manage the traffic of the dns-example.com service. Different services use different instances. This allows you to manage services with ease, use resources on demand, and reduce unnecessary costs.
Purchase an instance
Before you use GTM, you must purchase a GTM instance. For more information, see Create an instance.
1 . Instance ID/Name
Instance ID: After you purchase a GTM instance, the system generates an instance ID. The instance ID is a unique identifier for the application service. You can use the instance ID to perform the required operations. These operations include upgrading, renewing, and releasing the instance.
Instance name: When you configure basic settings for an instance, you can specify an informative name for the instance. This name allows you to memorize and identify the application service of the instance with ease.
2 . CNAME Access Domain Name
After you create a GTM instance, the system assigns a CNAME access domain name to the instance. Before you use GTM to route access traffic, you must perform the following steps: On the Manage DNS page, click the required domain name. On the DNS Settings page, click Add Record to add a CNAME record. In the CNAME record, connect the domain name with the CNAME access domain name that is assigned by GTM.
3 . Health Check Tasks
After you create an address pool and enable the health check feature, the system calculates the number of health check tasks. This number is generated after the system multiplies the number of IP addresses in the address pool by the number of the specified monitoring nodes.
If the health check feature is not enabled for an address pool, the quota for health check tasks is not calculated.
The Standard Edition supports a base quota of 100. The Ultimate Edition supports a base quota of 200. If the number of health tasks exceeds a base quota, you can upgrade the related instance to increase the number of detection tasks.
Use the following formula to calculate the number of health check tasks:
The number of health check tasks = The total number of addresses in Address Pool A × The total number of monitoring nodes in Address Pool A
If multiple address pools exist, the result of each address pool adds up to the total number of health check tasks.
4 . Notifications
This parameter indicates the number of notifications that were sent this month. The Standard Edition supports a base quota of 1,000 notifications per month. The Ultimate Edition supports a base quota of 2,000 notifications per month. If the number of notifications that are sent in a month exceeds a base quota, you can purchase an SMS notification plan to increase the quota. Find the required instance and click Upgrade next to the instance. On the Upgrade/Downgrade page, specify a number that you want to increase in the SMS Notifications field and click Buy Now.
5 . Status
Valid values: Normal and Abnormal.
Indicates that the health check feature is not enabled for an instance or the result of a health check is normal.
Indicates that the health check feature is enabled for an instance. If an exception is returned by an arbitrary health check, the instance is deemed abnormal.
Alert notifications include the following metrics:
6 . Package Version
Indicates the edition of the current instance. Valid values: Standard and Ultimate.
7 . Expired At
Indicates the expiration time of an GTM instance. You will receive a notification 1 day, 3 days, or 7 days before the expiration time.
8 . Configure
This action allows you to configure basic settings, access policies, address pool sets, and address pools for an GTM instance. This action also allows you to enable the health check feature for the GTM instance. After you click Configure next to a GTM instance, you are directed to the Basic Configuration page of the GTM instance by default.