Alibaba Cloud DNS:Instance FAQ

Paid editions provide higher service quality and broader guarantees:

• Service quality: Paid editions include a 100% SLA guarantee and expert technical support. The Free Edition offers no availability guarantee or technical support.

• Enhanced features:

  • More subdomain levels and granular TTL settings for greater resolution flexibility.

  • Intelligent parsing by carrier, cloud provider, and region to route users to the optimal path.

  • Higher IP address capacity for Server Load Balancer to handle complex traffic demands.

  • DNSSEC support and query volume statistics for enhanced security and analytics.

• Advanced features (Ultimate Edition):

  • More granular intelligent parsing.

  • DNS record backup and Secondary DNS for improved availability and security.

Compare all features in the Edition Comparison.

A: Go to the Alibaba Cloud DNS - Public Zone page and check the Edition column for your domain.

You can also view the edition and attached domain names for all of your instances on the Instance page.

A: Use one of the following methods:

• Method 1:

• Method 2: Adjust the TTL value of your DNS records. A larger TTL caches results longer at the local resolver, reducing queries to the authoritative server and lowering costs.

  Warning

  Read How to Configure TTL before changing TTL values.

• Method 3: Contact us on DingTalk (ID: behladu) for a business discount.

A: The Ultimate Edition is designed for enterprise customers. Given that enterprise domains face a higher risk of DNS attacks, DNS Security Defense is bundled by default to ensure business stability.

DNS Security Defense aims to address protocol-level attacks against DNS (such as DNS flood attacks). It cannot block forged DNS requests, but it ensures that normal resolution requests remain unaffected under attack traffic.

A: A paid instance is billed and attached per zone. Whether a subdomain requires its own instance depends on how the subdomain is hosted:

• Subdomains added as DNS records under a root domain: After the root domain is attached to a paid instance, the subdomains that are added under it as DNS records (for example, www or mail under example.com) automatically use the paid edition DNS of the root domain. No separate purchase or attachment is required.

• Independently hosted subdomains: If a subdomain is hosted as a separate domain name (zone) of its own (for example, sub.example.com is added separately), it counts as a domain name separate from the root domain. To use paid edition services, you need to attach it to a paid instance.

1. Log on to the Alibaba Cloud DNS – Public Authoritative DNS console.

2. Click Instance > Batch Auto-renewal.

3. Set Expires At to All, Product Name to Alibaba Cloud DNS (Subscription), and Region to All Regions. On the Manual Renewal tab, select the target instances and click Enable Auto-renewal.

   The auto-renewal payment date appears in the Countdown to Expiration column.

A: No. Each instance is purchased separately and has its own purchase date and expiration date. You can use the following alternatives:

• Attach multiple domains to a single instance: When you purchase an Ultimate Edition instance, set Attachable Domains to a larger number and attach multiple domains to this instance. All attached domains then share the same expiration date upon renewal.

• Enable auto-renewal: Select the auto-renewal option at purchase. The system automatically renews the instance before it expires. Auto-renewal can be canceled at any time.

A: No. The upgrade is seamless and does not interrupt DNS resolution. Post-upgrade steps depend on your domain registrar:

• Domain name is registered with Alibaba Cloud: Alibaba Cloud DNS automatically updates your DNS servers. If the update fails due to an update lock or a network issue, disable the lock and manually update the DNS servers. Modify Your Domain’s DNS Servers.

• Domain name is not registered with Alibaba Cloud: Change the DNS servers at your registrar to the ones assigned by Alibaba Cloud DNS.

A: Upgrading between paid editions may assign different DNS server names. This does not affect DNS resolution because all paid editions share the same server cluster: vip(1-8).alidns.com. Update the DNS servers at your registrar to the newly assigned names. Modify Your Domain’s DNS Servers.

A: Yes. Enterprise users can upgrade only to the Ultimate or Premium editions. Personal Edition is not available for enterprise users, and the Enterprise Standard Edition is no longer available for new purchases. The Ultimate and Premium editions include basic or full protection by default.

A: Attachable domains refers to the number of domains to be attached to the paid instance. To receive paid edition services, each domain must be attached to a paid instance.

To upgrade multiple domain names (for example, three domain names), you have two purchase options:

• Option 1: Purchase one instance, set Attachable Domains to 3, and attach the three domain names to this instance.

• Option 2: Purchase three instances, set Attachable Domain to 1 for each instance, and attach one domain name to each instance.

The total cost is the same for both options. Choose the option that best suits your domain name management requirements.

A: Increase the number of attachable domains when you purchase an instance. After the purchase is complete, attach the domains that you want to upgrade to the instance to complete the batch upgrade.

A: Alibaba Cloud DNS does not support edition downgrades. For example, you cannot downgrade from the Ultimate Edition to the Personal Edition.

• To use a lower-edition instance, Switch Your Domain to Another Instance.

• To switch from a paid instance to the Free Edition, Detach Your Domain from an Instance.

A: Direct edition downgrades are not supported. A switch from a paid instance to the Free Edition occurs when you detach the instance or when it expires. This switch can fail for the following reasons:

• If your domain is registered with Alibaba Cloud, the switch typically fails because an update lock is enabled. Run a WHOIS query to check. If the status shows Registrar-provided update lock, disable it and manually change your DNS servers to the Free Edition names. Modify Your Domain’s DNS Servers.

• Alibaba Cloud DNS does not support automatic DNS server switching for third-party registrar domains. Manually change the DNS servers to the Free Edition names at your registrar.

A: Yes, but complete the switch within seven days after your instance expires. After seven days, the instance is released and DNS resolution stops. Some DNS records may be paused and paid-only features become unavailable after the switch. Instance Expiration and Renewal.

A: Yes. You can request a partial refund for an active instance or cancel a future renewal. Cancel an Instance.

A: Alibaba Cloud retains your DNS data for a 7-day grace period after expiration. Renewing within this period preserves DNS resolution. If you do not renew, the instance is released. To prevent resolution failure:

• For domain names registered with Alibaba Cloud: The system automatically downgrades DNS settings to the Free Edition and pauses records that rely on paid features. If an update lock is enabled (check via WHOIS query for the status "Registrar-provided update lock") or a network timeout prevents the automatic downgrade, manually change the DNS servers to the Free Edition names in the Alibaba Cloud DNS console.

• For domain names registered with other registrars: DNS resolution is disrupted. Manually change your DNS servers to the Free Edition names.

Instance Expiration and Renewal.

A: Due to our massive user base, the Free Edition cluster experienced a sudden surge in query volume in 2026, posing significant stability risks to the service. To safeguard the basic DNS availability for the majority of our free users (primarily individual developers), starting June 24, 2026, a dynamic rate limiting policy is applied to domains with daily query volume exceeding 100,000. This may affect some enterprise domains with high query volumes.

When the overall cluster load is stable, we will do our best to ensure consistent resolution performance for all free users. However, during traffic spikes or periods of extreme concurrency, the rate-limiting policy will be dynamically adjusted based on real-time server load.

Other DNS providers also distinguish between free and paid editions; free editions carry no SLA guarantees and may similarly implement rate limiting when under capacity pressure.

A: Rate limiting for the Free Edition is calculated at the Zone level.

For example, If your root domain (zone) example.com is on the Free Edition and has a total daily query volume exceeding 200,000, across three subdomains:

• a.example.com: 50,000 queries per day

• b.example.com: 50,000 queries per day

• c.example.com: 100,000 queries per day

In this case, the cumulative volume of the Zone is 200,000 queries per day, which exceeds the threshold. Consequently, both the root domain example.com and all three subdomains will trigger dynamic rate limiting.

A: No. The system offers a one-time exemption:

• First exceedance: You receive a notification (email, SMS, or console message) informing you that your domain exceeded 100,000 queries the previous day. This is a reminder only, and your service is not affected.

• Second exceedance: If no action is taken and the domain exceeds the threshold again and receives a second notification, it will be added to the dynamic rate limiting candidate list.

A: Being on this list means your domain may experience temporary query rate limits during periods of high DNS cluster load. Dynamic rate limiting does not completely stop DNS resolution. It manifests as slower resolution responses or partial request drops (similar to the experience during network congestion).

• Trigger conditions: Rate limiting is only enforced when the Free Edition DNS cluster experiences heavy load or stability risks. If the cluster is running smoothly, your domain may not experience any rate limiting even if it is on the list.

• Prioritization: The system applies a weighted queue based on query volume. Domains with higher traffic are more likely to be throttled first during high-load scenarios.

• Throttling thresholds: The rate-limiting threshold is dynamic and adjusts in real-time based on cluster load to maintain overall system stability.

• Removal mechanism:

  • Your domain's daily query volume must remain below 100,000 for 7 consecutive calendar days. Then, it will be automatically removed from the list on Day 8.

  • If your domain exceeds the 100,000-query threshold on any single day during this 7-day cooldown period, the counter will immediately reset to zero, and you must start a new 7-day cycle.

How to check: Go to the Free Edition Usage Alerts page to view the daily query volume of domain names that have exceeded their quota.

Display rules:

• This page only displays domain names whose query volume from the previous day exceeded the limit or reached 70% of the quota. It also displays domain names whose total query volume over the last seven days exceeded 70,000.

• Domain names that have not exceeded the quota are not displayed on this page. This indicates that their usage is within the free quota and does not signify a system error.

• The data is refreshed daily and shows the cumulative query volume from the previous day. The data is not real-time.

Detailed query volume

The Free Edition does not provide a DNS query statistics feature or an API. To understand the source of DNS queries, view daily query volumes by subdomain, and configure real-time alerts, enable the DNS Traffic Analysis feature. After this feature is enabled, query volumes are calculated based on resolution logs, which provides more accurate statistics.

• DNS Traffic Analysis is a paid feature that uses a pay-as-you-go billing method. For more information, see DNS Traffic Analysis (Pay-as-you-go).

• After you enable DNS Traffic Analysis for the Free Edition, you can view only the DNS query data generated after the feature is enabled. Historical data cannot be viewed.

• You can disable the DNS Traffic Analysis feature at any time. Once disabled, no new log entries will be generated, and therefore no billing will apply.

Tthe DNS query volume for a Free Edition domain name is displayed as 0 on the Public Zone Domain Statistics page because the detailed data requires DNS Traffic Analysis to be enabled.

A: No, an upgrade is not mandatory. If your Free Edition domain exceeds 100,000 queries per day, you can choose to remain on the Free Edition if you are willing to accept the risk of dynamic rate limiting during peak cluster loads.

However, to ensure business continuity, system reliability, and production-grade performance, we highly recommend that enterprise users upgrade to a paid instance. The Free Edition does not come with any SLA guarantees.

A: Yes. You can increase the TTL (Time to Live) value of your DNS records. A longer TTL (for example, 3600 seconds) means that recursive resolvers (Local DNS) cache your DNS records for longer, reducing the number of queries forwarded to authoritative DNS servers.

A: Upgrade to a paid Public Zone instance (Personal Edition, Ultimate Edition, or Premium Edition). After upgrading, the domain is no longer subject to Free Edition rate limiting.

The following products cannot remove the Free Edition rate limit. Do not purchase them by mistake:

• DNS Traffic Analysis resource plan: This resource plan is only used to offset the pay-as-you-go billing costs of DNS Traffic Analysis.

• Public DNS resource plan: This resource plan applies to Recursive Gateway and HTTPDNS, and does not apply to Public Zone. It cannot remove the Free Edition rate limit.