The load balancer that you select must have the following features:
Load-balancing of traffic to a pool of real servers through a virtual host name. Browsers access services using the virtual host name, and the load balancer forwards the requests to the servers in the pool.
Port translation configuration support where requests are forwarded to a back-end server port that is different from the port in the request.
Port monitoring on the servers in the pool to determine availability of a service.
Virtual servers and port configuration, the ability to configure server aliases and ports that meet the following requirements on the external load balancer:
Support for multiple virtual server configurations
For each virtual server, the load balancer should allow configuration of traffic management on more than one port. For example, for Oracle HTTP Server, the load balancer should support a virtual server and port each for HTTP and HTTPS traffic.
Ability to associate each server alias with an IP address and be a part of the DNS. Clients must be able to access the external load balancer through server alias.
Node failure detection and the ability to stop routing traffic to a failed node
Fault-tolerant mode. Oracle recommends that the load balancer be configured in fault-tolerant mode.
Sticky routing, for example, cookie-based and IP-based persistence.
SSL acceleration. The load balancer should terminate SSL traffic and forward unencrypted traffic to the back-end servers using the equivalent non-SSL protocol.
Oracle recommends that you configure the load balancer virtual server to return immediately to the calling client when the back-end services to which it forwards traffic are unavailable. This configuration is preferred over the client disconnecting on its own after a timeout based on the TCP/IP settings on the client machine.