IBM Websphere Edge Components

IBM WebSphere Edge Components (formerly known as "IBM WebSphere Edge Server") is a set of web server/application server components that are intended to improve the performance of web-based systems, particularly as edge servers. It is part of the IBM WebSphere product suite. Current version is version 9.0. It consists of two independent products:

• Caching proxy
• Load balancer

Edge Server comprises 4 basic components:

• Load Balancer: Used to direct incoming requests to an appropriate server based on a set of rules which may include load balancing requests across several servers. Server selection is based upon health checks which includes the ability for the user to write specialized health check requests. The current level supports IPv4 and IPv6 traffic.
• Caching Proxy: The caching proxy system can be configured as either a forward- or reverse-proxy server. Requested content is cached by Edge before being sent to the requestor and subsequent requests can, based on its internal algorithm that can be customized, be served from the cache instead of forwarding them to application server for reprocessing. This improves response time and minimizes network bandwidth use. A primary use of Edge server is therefore to increase the performance and scalabity of J2EE applications.
• Content Distribution: This feature is used in conjunction with the load balancer, where multiple Edge server components are used, to distribute HTTP requests based on URL or other administrator configured characteristics, eliminating the need to store identical content on all Edge servers.
• Application Service at the Edge: Ability to build a dynamic web page from fragments generated by multiple application servers

Edge can be configured for high availability with a backup Edge failover server that takes over sessions if the primary Edge server fails.