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    Alibaba Cloud DNS:Upgrade a legacy GTM instance to GTM 3.0

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    Alibaba Cloud DNS:Upgrade a legacy GTM instance to GTM 3.0

    Last Updated:Jun 04, 2026

    GTM 3.0 improves configuration, scheduling, disaster recovery, and O&M over legacy versions (GTM 3.0 Upgrade Guide). Follow this procedure to upgrade a legacy instance.

    Note

    Automatic upgrades of legacy GTM instances to GTM 3.0 begin December 30, 2025 in batches. You receive notifications 1 month, 7 days, 3 days, and 1 day before your batch via SMS, email, and internal messages. The upgrade does not affect DNS resolution. To control the timing, migrate manually.

    • Legacy GTM includes two versions that predate GTM 3.0.

    • This upgrade does not apply to legacy GTM instances with a Latency-based Access Policy.

    Procedure

    Workflow

    1. Purchase a GTM 3.0 subscription instance. Subscription instances.

    2. Configure GTM 3.0 scheduling policies to match your legacy access policies. Common failover scenarios:

      How to implement primary/standby disaster recovery with GTM

      How to implement multi-active load balancing and failover with GTM

      How to implement ISP-based DNS resolution and failover with GTM

      How to implement geo-location-based intelligent DNS resolution with GTM

      How to implement dual-stack DNS resolution and failover with GTM

    3. Run health checks on the GTM 3.0 access domain name to verify that resolution results match the legacy instance.

    4. Update the CNAME record on your authoritative DNS to point your service domain name to the GTM 3.0 access domain name.

    5. Unsubscribe from the legacy GTM instance.

    Examples

    Assume your service domain name is ceshi.cloud-example.com and a legacy GTM instance manages it.

    Scenario 1: Different service and GTM access domains

    Note

    In this scenario, a CNAME record already points your service domain name to the GTM access domain name.

    1. If the CNAME access domain name on the Basic Configuration page uses the default value (such as gtm-cn-btz4**01.cloud-example.com), check the CNAME Access Domain Name (Public Network) field for the actual value (such as gtm-cn-btz4***.01.cloud-example.com).

    2. Verify that a CNAME record on your authoritative DNS points ceshi.cloud-example.com to the legacy GTM access domain name.

    3. Purchase a GTM 3.0 instance and configure the same access policy as your legacy instance. You can use the default access domain name.

      Important

      If your legacy instance uses a System-assigned Access Domain and your domains are not on Alibaba Cloud DNS, you cannot generate a GTM access domain name after upgrading. Solutions:

      In the Basic Configuration for Access Domain dialog box, select Bind Instance. Set Access Domain (such as cloud-example.com), Record Type (such as A - For scheduling of IPv4 addresses or domain names), and Global TTL (such as 30 seconds). Status defaults to Disabled. Enable DNS resolution only after configuring address pools, addresses, and load balancing policies.

    4. Run a health check on the GTM 3.0 access domain name to verify that resolution results match the legacy instance.

      Important

      Verify consistent resolution results before switching traffic.

    5. On the Modify Record page in the DNS console, update the CNAME Record Value to the GTM 3.0 access domain name. Set TTL to 10 minutes. Changes take effect in 10–30 minutes.

    Scenario 2: Same service and GTM access domains

    Note

    In this scenario, the GTM access domain name matches your service domain name, so no CNAME record is needed.

    1. On the Basic Configuration page of your legacy GTM instance, the CNAME access domain name is ceshi.cloud-example.com.

    2. Purchase a GTM 3.0 instance with the same access policy as your legacy instance. Set the access domain name to ceshi.cloud-example.com.

      Warning

      Configure all load balancing policies before enabling the instance. Once enabled, the access domain name takes effect immediately and overwrites legacy GTM policies.

      In the Access Domain Name Basic Configuration dialog box, set Record Type to A - Configure scheduling for IPv4 addresses or domain names and Global TTL to 30 seconds. Enabled Status defaults to Disabled.

    3. Verify that the GTM 3.0 access policy matches the legacy configuration, then Enable the access domain name instance.

      Important

      After enabling, the service domain is scheduled by the configured access policy. Ensure it matches the legacy configuration.