Virtual server is a scalable and highly available server built on a cluster of real servers. The architecture of the cluster is transparent to end users, and the users see only a single virtual server. Please consider the following figure,
The real servers may be interconnected by high-speed LAN or by geographically dispersed WAN. The front-end of the real servers is a load balancer, which schedules requests to the different servers and make parallel services of the cluster to appear as a virtual service on a single IP address. Scalability is achieved by transparently adding or removing a node in the cluster. High availability is provided by detecting node or daemon failures and reconfiguring the system appropriately.
The basic goal of the Linux Virtual Server Project is to:
Produce a high-performance and highly available server for Linux based on clustering, which provides a good scalability, reliability and serviceability.
Last updated: 1998/12/5
Created on: 1998/5/28