High volume web service resource consumption

In this paper we investigate the problem of providing consistency, availability and durability for Web Service transactions that consume anonymous and attribute based resources. We show that the availability of the popular lazy replica update propagation method can be achieved while increasing it´s durability and consistency. Our approach is based on an extension to the Buddy System, requiring that updates are preserved synchronously in two replicas, called buddies. Our system provides a new consistency constraint, Capacity Constraint, which allows the system to guarantee that resources are not over consumed and also allows for higher distribution of the consumption. Our method provides 1.) higher availability through the distribution of element master´s by utilizing all available clusters, 2.) consistency by performing the complete transaction on a single set of clusters, and 3.) a guaranteed durability by updating two clusters synchronously with the transaction.