What is Global Traffic Manager 3.0?

Global Traffic Manager (GTM) 3.0 is an upgraded version of the GTM service. It features graphical configuration, built-in health check templates, and multiple load balancing policies (proximity-based, weighted, sequential, and round-robin) with combinable request lines. GTM 3.0 enables flexible disaster recovery scheduling and fine-grained inbound traffic management.

Prerequisites

Familiarize yourself with the following concepts:

Product overview

GTM supports proximity-based access, high-concurrency load balancing, health checks, and failover for building active zone-redundancy and geo-disaster recovery architectures. GTM manages both Alibaba Cloud and non-Alibaba Cloud IP addresses, enabling disaster recovery for hybrid cloud applications.

GTM is a DNS-level service that returns service endpoints through DNS resolution. Clients connect to these endpoints directly. GTM is not a proxy or gateway — it does not process or inspect traffic between clients and services. Purchase Global Traffic Manager.

After you activate a GTM instance, configure a CNAME access domain name and create a CNAME record to map your business domain to the GTM access domain. This enables disaster recovery failover and intelligent resolution.

Features

GTM 3.0 provides the following core features.

Feature	Description	References
GTM access domain name	The GTM access domain name is the entry point through which GTM provides services. Map your business domain name to the GTM access domain name with a CNAME record. You need at least one independently hosted root domain or subdomain under your account, such as `example.com`. The format is `Host Record`.`Root Domain`, such as `gtm.example.com`. If your domain is hosted on Alibaba Cloud DNS, you can use the same host record as your business domain, making the GTM access domain name identical to your business domain name.	1. Access domain name configuration
Address pool	An address pool groups IP addresses or domain names that serve the same application and share ISP or regional properties. Configure multiple address pools to enable proximity-based access for users in different regions. If an address pool becomes unavailable, GTM switches traffic to a backup pool.	2. Address pool configuration
Address	An address is the application service endpoint that GTM returns to clients. It can be an IP address or domain name. The service port is used by health checks to verify availability.	3. Address configuration
Load balancing policy	A load balancing policy determines which address pool serves a domain and which address within that pool responds to requests. GTM supports the following methods: Proximity-based: Identifies the client's geographic location or ISP and directs traffic to the closest or same-ISP endpoint to minimize latency. Sequential: Selects address pools or addresses in a preset order. Round-robin: Distributes requests evenly across address pools and addresses. A pool is selected by round-robin, and addresses within that pool are returned in round-robin order. Weighted: Allocates requests based on weight values assigned to each server. Servers with higher weights handle more requests. These policies enable flexible inbound traffic distribution.	GTM 3.0 supports two-level access policy scheduling: First-level scheduling: Selects an address pool for the domain based on the load balancing policy. Get started. Second-level scheduling: Selects an available address from the pool and returns it to the client. 2. Address pool configuration.
Health check template	Health checks probe addresses in an address pool to evaluate service availability. Supported methods include ICMP ping, TCP connectivity, and HTTP/HTTPS endpoint monitoring. GTM 3.0 provides health check templates for configuring multi-protocol detection to assess address availability.	4. Probing templates

How it works

For example, the business domain name of a website is www.example.com.

Add three server IP addresses, 1.1.XX.XX, 2.2.XX.XX, and 3.3.XX.XX, to the GTM address pool and enable health checks.
Configure an access policy.
Activate a GTM instance and complete the basic configuration. A CNAME access domain name is generated, such as gtm.example.com.
Create a CNAME record to map the business domain name www.example.com to gtm.example.com.

Flowchart

DNS resolution flow

A client queries the local recursive DNS for the application service domain name www.example.com.
If no cache exists for www.example.com, the local recursive DNS queries a root DNS server, which returns the address of the .com DNS server.
After receiving the .com DNS server address, the local recursive DNS queries the .com DNS server for www.example.com. The .com DNS server returns the address of the example.com DNS server. If the domain uses Alibaba Cloud DNS, this points to an Alibaba Cloud DNS server.
After receiving the .com TLD server response, the local recursive DNS queries Alibaba Cloud DNS for www.example.com. Alibaba Cloud DNS finds the CNAME record mapping www.example.com to gtm.example.com and returns gtm.example.com.
The local recursive DNS receives gtm.example.com and queries the GTM DNS server for gtm.example.com. GTM evaluates its configured policies and returns the application service IP address.
The local recursive DNS returns the IP address for www.example.com to the client and caches it for subsequent queries.
The client connects directly to the application service at the returned IP address.

Service architecture

The service architecture includes:

The DNS module resolves requests to addresses in application service address pools. For example, mainland China users access address pool A while overseas users access address pool B, both using the Sequential policy.
The HealthCheck module probes application service addresses from multiple regions using ping, TCP, or HTTP/HTTPS.
If an address fails a health check, the DNS module removes it from the available list. When the address recovers, the DNS module restores it.

This ensures that users are automatically routed to the optimal application service without interruption.

System architecture

GTM consists of two layers:

Control layer: Provides services through the console and OpenAPI for CRUD operations on DNS records, configurations, monitoring data, and logs. Located in the China (Zhangjiakou) and China (Hangzhou) regions.
Resolution layer: Serves DNS queries through globally deployed server clusters. Receives DNS record data from the control layer and has nodes on major continents worldwide.

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