Eddie contains in-built real-time load monitoring routines to track the usage of each Back End Server (shown in black) on your site. This information is passed to a set of designated Front End Servers (shown in blue) which perform Admission Control.

The Eddie Front End Servers maintain a table of active sessions, tracking users who are currently interacting with the site. As a client request comes in, a check is made to see if this user has visited the site recently, say in the last ten minutes. If they have, the request is immediately passed to the appropriate server. If they have not, the Front End asks the question,

Are there sufficient resources to serve this customer properly right now?

If there are not sufficient resources, the Front End queues the request and returns a page to the client asking them to be patient and informing them that their request will be processed as soon as the next server becomes available (much like waiting in queue for an airline booking operator over the telephone). When the resources to process the request become available, the request is passed to a server.

Eddie dynamically adjusts the rate at which new customers are accepted to match resource availability. In this way Eddie can provide rapid response time for every transaction the customer initiates during a session with the site.