Cache Server Weight

Weighted round robin is a round robin algorithm that takes into account a weight assigned to each cache server. Weight is a way of accounting for the resource differences between servers. If a server has the capacity to handle twice the number of sessions as another server, its weight ratio to the other server can be set to 2:1. The default weight for all cache servers is 1. When all cache servers are configured with the default weight, each cache server is treated equally. When a non-default weight is applied to any cache servers in the web cache server farm, the algorithm takes that weight into account when assigning sessions to the cache servers.

Consider the following example. A server farm contains three cache servers with the following weights: server A has a weight of 1, server B has a weight of 2, and server C has a weight of 3. For each six (the sum of the three weights) active sessions, server A will be assigned 1 session, server B will be assigned 2 sessions, and server C will be assigned 3 sessions in a round robin fashion. For this example, the weight ratio between the three servers would be 1:2:3.