Web OS 10.0 Application GuideChapter 10: Health Checking n 221212777-A, February 2002Real Server Health ChecksAlteon Web switches running Server Load Balancing (SLB) monitor the servers in the realserver group and the load-balanced application(s) running on them. If a switch detects that aserver or application has failed, it will not direct any new connection requests to that server.When a service fails, an Alteon Web switch can remove the individual service from the load-balancing algorithm without affecting other services provided by that server.By default, the Web switch checks the status of each service on each real server every two sec-onds. Sometimes, the real server may be too busy processing connections to respond to healthchecks. If a service does not respond to four consecutive health checks, the switch, by default,declares the service unavailable. You can modify both the health check interval and the numberof retries.N OTE – Health checks are performed sequentially when used in conjunction with a virtualserver configured with multiple services and groups. As a result, the actual health-check inter-val could vary significantly from the value set for it using the inter parameter.>> # /cfg/slb/real <real server number> (Select the real server)>> Real server# inter 4 (Check real server every 4 seconds)>> Real server# retry 6 (If 6 consecutive health checks fail,declare real server down)
