Web OS 10.0 Application Guide290 n Chapter 12: Global Server Load Balancing 212777-A, February 2002GSLB OverviewGSLB allows balancing server traffic load across multiple physical sites. The Alteon GSLBimplementation takes into account an individual site’s health, response time, and geographiclocation to smoothly integrate the resources of the dispersed server sites for complete globalperformance.BenefitsGSLB meets the following demands for distributed network services: High content availability is achieved through distributed content and distributed decisionmaking. If one site becomes disabled, the others become aware of it and take up the load. There is no latency during client connection set up. Instant site hand-off decisions can bemade by any distributed switch. The best performing sites receive a majority of traffic over a given period of time but arenot overwhelmed. Switches at different sites regularly exchange information through the Distributed SiteState Protocol (DSSP), and can trigger exchanges when any site’s health status changes.This ensures that each active site has valid state knowledge and statistics. GSLB implementation takes geography as well as network topology into account. Creative control is given to the network administrator or Webmaster to build and controlcontent by user, location, target application, and more. GSLB is easy to deploy, manage, and scale. Switch configuration is straightforward. Thereare no complex system topologies involving routers, protocols, and so forth. Flexible design options are provided. All IP protocols are supported.Compatibility with Other Web OS Features URL-based server load balancing is compatible with GSLB. Cookie-based persistence is compatible with GSLB: cookie rewrite and cookie insertmodes.
