Scalability
Scalability is the ability of the system to adapt to increased service load. A scalable system will respond more gracefully to increased load than a non scalable one. First, its performance disgrace more moderately and second, its resources acquire a longer time to reach a saturated state. A scalable system must have the potential to grow without having to resort to expensive design modifications. Secondly, adding a machine to the distributed system must not be clogging the network. Therefore scalable design should withstand high service load and accommodate the growth of the user community, and facilitate simple integration of added resources.