：Tutorial overview

This tutorial describes how to create a GTM instance, automatically allocate the user access traffic to two IP addresses, and set health check, to realize failover.

This tutorial contains the following steps:

1. Create an instance:

   You need to create a GTM instance for the application service before using the GTM service.

2. Make global settings:

   Before using the GTM service, make global settings for the GTM instance created.

3. Create an address pool:

   Before using the GTM service, create an address pool for managing the addresses of the application service.

4. Enable health check:

   To obtain the real-time availability status of the application service, enable health check for the addresses of the application service.

5. Configure an access policy:

   To use the GTM service, enable DNS Failover and configure an access policy so that users in different network regions access different addresses of the application service.

6. Realize CNAME access:

   After the GTM instance is configured and passes the test, resolve the primary domain name of the application service to the domain name of the GTM instance in CNAME mode, to connect the application service to the GTM instance.