Alibaba Cloud provides two editions of Application Load Balancer (ALB) instances: basic and standard. The features and limits vary by edition. This topic compares the features and limits of basic and standard ALB instances.
Differences
The following table describes the features supported by basic and standard ALB instances.
| Feature | Basic | Standard |
|---|---|---|
| Listener protocol | ||
| Quick UDP Internet Connections (QUIC) | Supported | Supported |
| HTTP/2 | Supported | Supported |
| WebSocket | Supported | Supported |
| Forwarding rule | ||
| Distribute network traffic based on domain names or URLs | Supported | Supported |
| Distribute network traffic based on HTTP headers | Supported | Supported |
| Distribute network traffic based on query strings | Not supported | Supported |
| Distribute network traffic based on cookies | Not supported | Supported |
| Distribute network traffic based on HTTP request methods | Not supported | Supported |
| Distribute network traffic based on source IP address | Not supported | Supported |
| Distribute network traffic based on response status codes | Not supported | Supported |
| Distribute network traffic based on response headers | Not supported | Supported |
| Redirects | Supported | Supported |
| Rewrite requests or return custom responses | Not supported | Supported |
| Add or delete headers | Not supported | Supported |
| Traffic mirroring | Not supported | Supported (submit a ticket to be included in the whitelist first) |
| QPS throttling | Not supported | Supported (submit a ticket to be included in the whitelist first) |
| AScript | Not supported | Supported (submit a ticket to be included in the whitelist first) |
| Security | ||
| Access control based on whitelists and blacklists | Supported | Supported |
| TLS cipher suites | Supported | Supported |
| Server Name Indication (SNI) for multiple certificates | Supported | Supported |
| Rivest-Shamir-Adleman (RSA) and elliptic-curve cryptography (ECC) certificates | Supported | Supported |
| ECC certificates | Supported | Supported |
| End-to-end data transfer over HTTPS | Not supported | Supported |
| Custom TLS cipher suites | Not supported | Supported |
| TLS 1.3 | Supported | Supported |
| Monitoring | ||
| Access logs | Supported | Supported |
Limits
| ALB | Basic | Standard |
|---|---|---|
| Instance | ||
| The number of additional certificates that can be added to each ALB instance (excluding default certificates) | 10 | 25 |
| The number of forwarding rules that can be configured for each ALB instance (excluding default forwarding rules) | 40 | 100 |
| The number of listeners that can be added to each ALB instance | 50 | 50 |
| The number of backend servers that can be added to each ALB instance | 200 | 1000 |
| Listener | ||
| The number of network access control lists (ACLs) that can be associated with each listener | 3 | 3 |
| The number of network ACL entries that can be associated with each listener | 300 | 1000 |
| Region | ||
| The number of custom security polices supported in each region | 50 | |
| The number of health check templates supported in each region | 50 | |
| The number of ALB instances supported in each region | 60 | |
| The number of network ACLs supported in each region | 1000 | |
| The number of server groups supported in each region | 3000 | |
| Server group | ||
| The number of listeners or forwarding rules that can be associated with each server group | 50 | |
| The number of ALB server groups in which a backend server (IP address) can be specified | 200 | |
| The number of backend servers (IP addresses and ports) that can be added to each server group | 1000 | |
| Forwarding rule | ||
| The number of actions that can be specified in each forwarding rule | 3 | 5 |
| The number of match conditions that can be specified in each forwarding rule | 5 | 10 |
| The number of wildcards that can be used in each forwarding rule | 5 | 10 |
| Network ACL and security policy | ||
| The number of listeners that can be associated with each network ACL | 50 | |
| The number of entries that can be added to each network ACL | 1000 | |
| The number of listeners that can be associated with each custom security policy | 10 | |