To index sources and respond to queries, all the AFS modules can run in single or multiple mode, on one or more computers in order to ensure the best performance and availability of the search solution that fit the functional needs and constraints.
The modular approach makes it possible to associate a specific self-sustaining software share to a solution function. This affords a wide implementation flexibility. Every configuration scheme can be imagined, from a single server hosting all the modules and performing all the functions, to setting up tens or hundreds of servers to index hundreds million documents and to respond to tens million monthly queries.
For example, to cope with large volumes, an index can be cut into layers. Each layer can be processed by a distinct reply agent. A middle agent takes care of smoothing the splitting for the rest of the solution and virtualizing the reply agents as if a unique agent for the whole source index.
When designing the physical architecture, the following issues must be considered: