PrivateZone limits - zones, records, VPC, QPS throttling - Alibaba Cloud DNS

Lists the quotas and constraints for PrivateZone zones, DNS records, VPC associations, QPS throttling, and forwarding rules.

Built-in authoritative limits

Limit item	Limit threshold	Description
Number of domains (zones)	500	Each account supports up to 500 zones.
Number of VPCs that you can associate with a zone	100	Each zone supports up to 100 associated VPCs.
Number of accounts from which you can associate VPCs	200	Supports VPCs from up to 200 Alibaba Cloud accounts.
Number of DNS records	100,000 (Standard zone)	Each zone supports up to 100,000 DNS records in both standard and accelerated zones. To increase this quota, submit a ticket.
Number of DNS records	100,000 (Accelerated zone)
Weight policy	Not supported (Standard zone)	When multiple IP addresses are configured for the same host record, responses return all IPs based on preset weights to distribute traffic across servers for load balancing.
Weight policy	Supported (Accelerated zone)
Custom internal line resolution	Not supported (Standard zone)	Customize the built-in authoritative DNS to return specific IP addresses for requests from designated internal IP segments. Limits.
Custom internal line resolution	Supported (Accelerated zone)
Total resolution requests from a single ECS instance in a VPC	5,000 per second	Each ECS instance supports up to 5,000 DNS requests per second. Exceeding this limit may trigger throttling, and the 99.99% SLA availability may not be guaranteed.
Total resolution requests from all ECS instances in a VPC	No limit	No limit on aggregate resolution requests across all ECS instances in a VPC.
External recursive resolution requests from a single ECS instance in a VPC	600 per second	Each ECS instance supports up to 600 external recursive requests per second. Exceeding this limit may trigger throttling.
Total external recursive resolution requests from all ECS instances in a VPC	5,000 per second	The aggregate limit for external recursive requests across a single VPC is 5,000 per second. Exceeding this limit may trigger throttling.
Batch operations	Limits	Supports batch deletion of domains, import of DNS records, and pausing/enabling DNS records.
Inbound endpoint	Limits	Allocate custom inbound endpoints to avoid address conflicts with 100.100.2.136/100.100.2.138 when accessing cloud DNS from outside the cloud.
Wildcard DNS record	-	Wildcard DNS records are supported regardless of the recursive resolution proxy setting for subdomains.

Warning

The QPS throttling parameters for various query requests within a VPC are global indicators and cannot be adjusted.

Throttling of external recursive queries: Add a domain name for cache retention.
Throttling of ECS DNS queries: How do I mitigate ECS DNS query request throttling?.
Throttling alert configuration: Throttling alert notifications.
To view triggered throttling details, enable Private Zone traffic analysis.

Domain (zone) format limits

Maximum length: 200 characters. Minimum level: 1.

Note
Levels are separated by dots. a = level 1, a.b = level 2, a.b.c = level 3, and so on.
Maximum domain (zone) level: 16
Maximum host record level: 20

Note
The maximum FQDN level is therefore 36 (16 + 20).
Top-level domain: 2-63 characters. Other levels: 1-63 characters. Allowed characters: hyphens, underscores, numbers, and lowercase letters. Must start with a number or lowercase letter.

Note
In www.aliyun.com: com allows 2-63 characters, aliyun allows 1-63 characters, and www allows 1-63 characters.
Reverse lookup domains end with .in-addr.arpa

Forwarding limits

Limit item	Limit threshold	Description
Number of endpoints per user	20	Maximum 20 endpoints per user.
Number of forwarding rules per user	1000	Maximum 1,000 forwarding rules per user.
Number of outbound endpoint IPs	Minimum: 2, Maximum: 6	Each outbound endpoint requires 2-6 IP addresses.
Number of target IPs for forwarding rules	6	Maximum 6 target IP addresses per forwarding rule.
Number of VPCs that can be bound to a forwarding rule	100	Maximum 100 VPCs per forwarding rule.
Domain level for forwarding domains (zones)	16	Maximum 16 domain levels. Exceeding this limit returns an invalid zone name error.

Important

Domain query requests from outbound endpoints are considered external DNS query requests and are subject to the limit on external recursive resolution requests from a single ECS instance in a VPC, which is 600 per second.