Sticky sessions ensure that requests from the same client are forwarded to the same backend server. ELB supports three types of sticky sessions. Table 3 lists the relationships between load balancing algorithms and sticky session types of classic load balancers. Table 1 lists the relationships between load balancing algorithms and sticky session types of shared load balancers, and Table 2 lists the relationships between load balancing algorithms and sticky session types of dedicated load balancers.
Classic load balancers can no longer be created on the management console. Use shared load balancers or dedicated load balancers instead.
Load Balancing Algorithm |
Sticky Session Type |
Layer 4 (TCP/UDP) |
Layer 7 (HTTP/HTTPS) |
---|---|---|---|
Weighted round robin |
Source IP address |
Supported |
Not supported |
Load balancer cookie |
N/A |
Supported |
|
Application cookie |
N/A |
Supported |
|
Weighted least connections |
Source IP address |
Not supported |
Not supported |
Load balancer cookie |
N/A |
Not supported |
|
Application cookie |
N/A |
Not supported |
|
Source IP hash |
Source IP address |
N/A |
Not supported |
Load balancer cookie |
N/A |
Not supported |
|
Application cookie |
N/A |
Not supported |
Load Balancing Algorithm |
Sticky Session Type |
Layer 4 (TCP/UDP) |
Layer 7 (HTTP/HTTPS) |
---|---|---|---|
Weighted round robin |
Source IP address |
Supported |
Not supported |
Load balancer cookie |
N/A |
Supported |
|
Application cookie |
N/A |
Not supported |
|
Weighted least connections |
Source IP address |
Not supported |
Not supported |
Load balancer cookie |
N/A |
Not supported |
|
Application cookie |
N/A |
Not supported |
|
Source IP hash |
Source IP address |
N/A |
Not supported |
Load balancer cookie |
N/A |
Not supported |
|
Application cookie |
N/A |
Not supported |
Load Balancing Algorithm |
Sticky Session Type |
Layer 4 (TCP/UDP) |
Layer 7 (HTTP/HTTPS) |
---|---|---|---|
Round robin |
Source IP address |
Supported |
Not supported |
Load balancer cookie |
N/A |
Supported |
|
Application cookie |
N/A |
Not supported |
|
Least connections |
Source IP address |
Supported |
Not supported |
Load balancer cookie |
N/A |
Not supported |
|
Application cookie |
N/A |
Not supported |
|
Source IP hash |
Source IP address |
N/A |
Not supported |
Load balancer cookie |
N/A |
Not supported |
|
Application cookie |
N/A |
Not supported |
Generally, the weighted round robin algorithm is recommended. Sticky sessions at Layer 4 use source IP addresses to main sessions, and sticky sessions at Layer 7 use load balancer cookies.
Parent topic: Listener