Policy Controlled Message Transformations

When implementing a heterogeneous service infrastructure several criteria must be met to exchange information between a service provider and a service consumer. Most often a homogeneous messages model is recommended to describe messages within such an ecosystem. Most organizations architectures´ though have evolved without such meta-model; and therefore, a message transformation model is necessary to convert from one service representation to the other. In this paper we propose and validate a meta - processing model that allows a service to transform a message before the main processing starts in the service using a policy language. These message transformations are based on dynamic policies that control and govern the individual message properties. From a processing perspective we are using an interceptor pattern on the service node itself and apply our policy term rewriting rules to the message. This approach not only provides the mathematical foundation for message transformations using policies (rewrite rules) but also allows us to extend the model for other policy related control problems.