Quotas and limits
Application Load Balancer (ALB) enforces two categories of constraints: fixed limits that cannot be changed, and adjustable quotas that you can request to increase.
To view your current quotas or request an increase, go to Quota Center or the Quota Center page in the Load Balancer Console.
Fixed limits
The following limits are hard limits. They apply to all editions (Basic, Standard, and WAF-enabled) unless otherwise noted, and cannot be increased.
Listener limits
Resource | Edition | Limit |
ACLs per listener | Basic / Standard / WAF-enabled | 3 |
ACL entries per listener | Basic | 300 |
ACL entries per listener | Standard / WAF-enabled | 500 |
Forwarding rule limits
Resource | Edition | Limit |
Actions per forwarding rule | Basic | 3 |
Actions per forwarding rule | Standard / WAF-enabled | 5 |
Match conditions per forwarding rule | Basic | 5 |
Match conditions per forwarding rule | Standard / WAF-enabled | 10 |
Wildcard entries per forwarding rule | Basic | 5 |
Wildcard entries per forwarding rule | Standard / WAF-enabled | 10 |
Server group limits
Resource | Edition | Limit |
Backend servers (IP addresses and ports) per server group | Basic / Standard / WAF-enabled | 1,000 |
ACL and security policy limits
Resource | Edition | Limit |
Associated listeners per ACL | Basic / Standard / WAF-enabled | 50 |
ACL entries per ACL | Basic / Standard / WAF-enabled | 500 |
Associated listeners per custom security policy | Basic / Standard / WAF-enabled | 10 |
ACL entries per ALB instance | Basic / Standard / WAF-enabled | 800 |
Regional limits
Resource | Edition | Limit |
Custom security policies per region | Basic / Standard / WAF-enabled | 50 |
Health check templates per region | Basic / Standard / WAF-enabled | 50 |
ACLs per region | Basic / Standard / WAF-enabled | 1,000 |
Server groups per region | Basic / Standard / WAF-enabled | 3,000 |
Concurrent connection limit
The following limits apply only to upgraded ALB instances. Pre-upgrade instances are not affected.
Within a single availability zone, an ALB instance supports a maximum of 250,000 concurrent connections to a single backend server or IP address. Exceeding this limit may cause port allocation failures and affect new connections.
To stay within this limit:
Reserve at least 8 IP addresses in each vSwitch where the ALB instance is located, and allow the CIDR blocks of these vSwitches in advance.
Make sure the security group rule quota for your ECS instances or Elastic Network Interfaces (ENIs) is large enough to accommodate rules added by the ALB-managed security group.Security Group rule Quota for your ECS Instances or Elastic Network Interfaces (ENIs)
Add more backend servers or IP addresses to the server group to distribute connection load across multiple targets.
The ALB-managed security group automatically adds rules with priority 1 to allow local IP traffic. The combined rule count must satisfy: ALB-managed security group rules + custom security group rules associated with the ALB instance ≤ security group rule quota for an ECS instance or ENI. For details, see ALB security group limits.
General quotas
General quotas have default values and can be increased up to a specified maximum. The values below are defaults — check the console for your actual quota values.
If the same backend server is associated with multiple listeners and forwarding rules of an ALB instance, each association counts separately toward the backend servers per ALB instance quota.
Instance quotas
Quota name | Description | Default | Adjustable |
alb_quota_loadbalancers_num | ALB instances per account per region | 60 |
Basic edition instance quotas
Quota name | Description | Default | Adjustable |
alb_quota_loadbalancer_certificates_num_basic_edition | Additional certificates per ALB instance (default certificate excluded) | 10 | |
alb_quota_loadbalancer_rules_num_basic_edition | Forwarding rules per ALB instance (default rule excluded) | 40 | |
alb_quota_loadbalancer_servers_num_basic_edition | Backend servers per ALB instance | 200 | |
alb_quota_loadbalancer_listeners_num_basic_edition | Listeners per ALB instance | 50 |
Standard edition instance quotas
Quota name | Description | Default | Adjustable |
alb_quota_loadbalancer_certificates_num_standard_edition | Additional certificates per ALB instance (default certificate excluded) | 25 | |
alb_quota_loadbalancer_rules_num_standard_edition | Forwarding rules per ALB instance (default rule excluded) | 100 | |
alb_quota_loadbalancer_servers_num_standard_edition | Backend servers per ALB instance | 1,000 | |
alb_quota_loadbalancer_listeners_num_standard_edition | Listeners per ALB instance | 50 |
WAF-enabled instance quotas
Quota name | Description | Default | Adjustable |
alb_quota_loadbalancer_certificates_num_standardwithwaf_edition | Additional certificates per ALB instance (default certificate excluded) | 25 | |
alb_quota_loadbalancer_rules_num_standardwithwaf_edition | Forwarding rules per ALB instance (default rule excluded) | 100 | |
alb_quota_loadbalancer_servers_num_standardwithwaf_edition | Backend servers per ALB instance | 1,000 | |
alb_quota_loadbalancer_listeners_num_standardwithwaf_edition | Listeners per ALB instance | 50 |
Listener quotas
Quota name | Description | Default | Adjustable |
alb_quota_max_request_timeout | Maximum request timeout per listener | 600 seconds | |
alb_quota_max_idle_timeout | Maximum idle timeout per listener | 600 seconds |
The 3,600-second maximum applies only to upgraded ALB instances. For non-upgraded instances, the maximum is 900 seconds.
Server group quotas
Quota name | Description | Default | Adjustable |
alb_quota_server_added_num | Server groups a single backend server (by IP address) can be added to | 200 | |
alb_quota_servergroup_attached_num | Times a single server group can be associated with listeners and forwarding rules | 50 | |
alb_quota_server_groups_weight | Maximum weight for a server group as a forwarding rule target | 100 | Yes, up to 10,000 — Contact Sales |
Reserved capacity quotas
Quota name | Description | Default | Adjustable |
alb_quota_reserved_capacity_units_per_loadbalancer | Maximum reserved Load Balancer Capacity Units (LCUs) per ALB instance | 5,000 | Contact Sales |
alb_quota_reserved_capacity_units_per_region | Maximum reserved LCUs per region | 20,000 | Contact Sales |
API rate quotas
View ALB API rate quotas in Quota Center.
Privilege quotas
Privilege quotas cover features that require authorization from Alibaba Cloud. These features are unavailable by default until access is granted.
Quota ID | Description | Application |
slb_user_visible_gray_label/ip_target_cidr_not_limited | Unrestricted CIDR blocks for IP-based server groups | |
slb_user_visible_gray_label/alb_extensible_edition | Extended edition for ALB | |
slb_user_visible_gray_label/alb_resource_reservation | Resource reservation for ALB | |
slb_user_visible_gray_label/support_sm_certificate | SM certificate support for ALB |
Manage quotas
You can manage ALB quotas in two consoles:
Quota Center — use this when managing quotas across multiple Alibaba Cloud services.
Load Balancer Console — use this when managing ALB quotas only.
View quotas
Quota Center
Log in to the Quota Center console. In the left-side navigation pane, click Product List and select a quota type: General Quotas, API Rate Limits, or Privileges.
In the Networking section, click Application Load Balancer (ALB).Quota Center pageQuota Center consoleQuota Center pageQuota Center consoleQuota Center pageQuota Center consoleQuota Center pageQuota Center consoleQuota Center
Load Balancer Console
Log in to the Quota Center page in the Load Balancer Console and select Application Load Balancer (ALB) as the product.
Select a quota type — General Quota, API Rate Limit, or Privilege — to view quota details.
Increase quotas
Quota Center
Log in to the Quota Center console. In the left-side navigation pane, click Product List, select General Quotas or Privileges, and click Application Load Balancer (ALB) in the Networking section.
Find the quota and click Apply in the Actions column.
In the dialog box, enter the required information and click OK.
Load Balancer Console
Log in to the Quota Center page in the Load Balancer Console and select Application Load Balancer (ALB) as the product.
Select General Quota or Privilege, find the quota, and click Apply in the Actions column.
In the dialog box, enter the required information and click OK.
The Technical Support team reviews each quota increase request. Provide a realistic target value and a clear justification. Alibaba Cloud notifies you of the approval status by SMS and email.
Create alert rules
Set an alert rule for a general quota to receive a notification before you reach the limit. Alert rules are available for the following ALB quotas:
Category | Quota parameter |
Additional certificates | alb_quota_loadbalancer_certificates_num_basic_edition |
Additional certificates | alb_quota_loadbalancer_certificates_num_standard_edition |
Additional certificates | alb_quota_loadbalancer_certificates_num_standardwithwaf_edition |
Forwarding rules | alb_quota_loadbalancer_rules_num_basic_edition |
Forwarding rules | alb_quota_loadbalancer_rules_num_standard_edition |
Forwarding rules | alb_quota_loadbalancer_rules_num_standardwithwaf_edition |
Backend servers | alb_quota_loadbalancer_servers_num_basic_edition |
Backend servers | alb_quota_loadbalancer_servers_num_standard_edition |
Backend servers | alb_quota_loadbalancer_servers_num_standardwithwaf_edition |
Listeners | alb_quota_loadbalancer_listeners_num_basic_edition |
Listeners | alb_quota_loadbalancer_listeners_num_standard_edition |
Listeners | alb_quota_loadbalancer_listeners_num_standardwithwaf_edition |
Server groups | alb_quota_servergroup_attached_num |
Backend server (IP) | alb_quota_server_added_num |
Region | alb_quota_loadbalancers_num |
Quota Center
Log in to the Quota Center console. In the left-side navigation pane, click Product List, select General Quotas, and click Application Load Balancer (ALB) in the Networking section.
Find the quota and click Create Alarm Rule in the Actions column.
On the Create Alarm Rule page, configure the alert parameters and click Confirm. For details, see Create a general quota alert.
Load Balancer Console
Log in to the Quota Center page in the Load Balancer Console and select Application Load Balancer (ALB) as the product.
Select General Quota, find the quota, and click Create Alarm Rule in the Actions column.
On the Create Alarm Rule page, configure the alert parameters and click Confirm. For details, see Create a general quota alert.
Create quota templates
Apply quota settings uniformly across member accounts in your Resource Directory.
Prerequisites
Before you begin, ensure that you have:
A management account
Quota Center
Log in to the Quota Center console. In the left-side navigation pane, click Product List, select General Quotas or Privileges, and click Application Load Balancer (ALB) in the Networking section.
Find the quota and click Create Quota Template in the Actions column.
In the Create Quota Template dialog box, configure the settings and click OK.
Load Balancer Console
Log in to the Quota Center page in the Load Balancer Console and select Application Load Balancer (ALB) as the product.
Select General Quota or Privilege, find the quota, and click Create Quota Template in the Actions column.
In the Create Quota Template dialog box, configure the settings and click OK.