Each type of load balancer has their advantages.
Classic load balancers can no longer be created on the management console. Use shared load balancers or dedicated load balancers instead.
Table 1 compares the features supported by the two types of load balancers. √ indicates that an item is supported, and — indicates that an item is not supported.
Feature |
Description |
Classic |
Shared |
---|---|---|---|
Load balancing over public and private networks |
|
√ |
√ |
Layer 4 and Layer 7 load balancing |
|
√ (UDP is not supported for load balancers on a private network.) |
√ |
Load balancing algorithm |
Round robin, least connections, and source IP hash |
√ |
√ |
Sticky session |
If you enable sticky sessions, requests from the same client will be routed to the same backend server during the session. |
√ |
√ |
WebSocket protocol |
WebSocket is a new HTML5 protocol that provides full-duplex communication between the browser and the server. WebSocket saves server resources and bandwidth, and enables real-time communication. |
√ |
√ |
Domain name- or URL-based forwarding |
ELB allows you to add forwarding policies to forward requests to different backend server groups based on the domain names or URLs specified in the forwarding policies. |
— |
√ (Currently, you can add forwarding policies only to HTTP or HTTPS listeners.) |
Adding ECSs as backend servers |
You can add ECSs to backend server groups to handle requests from load balancers. |
√ |
√ |
Whitelist-based access control |
You can whitelist the IP addresses that can access a listener. |
— |
√ |
Standard OpenStack APIs |
OpenStack APIs are supported and are compatible with self-developed APIs. |
— |
√ |
Adding BMSs as backend servers |
BMSs can also be used as backend servers to handle requests distributed by load balancers. |
— |
√ |
SNI for certificates |
Server Name Indication (SNI) is an extension to Transport Layer Security (TLS) and is used in cases that a server uses multiple domain names and certificates. After SNI is enabled, certificates corresponding to the domain names are required. |
√ |
√ |
SSL protocol |
Load balancers use SSL to receive requests from clients. |
√ |
— |
OBS storage for access logs |
Access logs of load balancers can be dumped to OBS buckets for storage. |
√ |
— |
Server weight |
You can configure different weights for backend servers when you select the round robin or least connections as the load balancing algorithm. |
— |
√ |
Modifying certificate content |
You can modify the content of a certificate. |
— |
√ |
Mutual authentication |
The identities of both communication parties are authenticated to ensure security. You need to deploy both the server certificate and client certificate. Only HTTPS listeners support this feature. |
— |
√ |
HTTP redirection |
HTTP traffic is redirected to HTTPS. When the client sends an HTTP request, the backend server returns an HTTPS response. |
— |
√ |
Performance monitoring on a per listener basis |
Cloud Eye allows you to monitor your resources, including load balancers. |
— |
√ |