Abstract
In this paper we investigate the problem of providing consistency, availability and durability for Web Service-transactions. We consider each transaction as a black box, with only the corresponding metadata, expressed as UML specifications, as transaction semantics. We refer to these WS transactions as coarse-grained WS transactions. We propose an approach that guarantees the availability of the popular lazy replica update propagation method while increasing the durability and consistency. In this paper we extend our previous work, called the Buddy System, to handle course grained WS transactions, we are using UML stereotypes that allow scheduling semantics from the design model to support: 1.) High availability by distributing service requests across all available clusters. 2.) Consistency by performing the complete transaction on a single set of clusters. 3.) Durability by updating two clusters synchronously.
