Service composition in a TINA environment

Abstract

In many of today's complex technical production processes the final product is produced from existing parts. The same concept can be applied to the development of software and leads to a component oriented software design. This step towards composing services from existing parts rather than starting a complete development each time has been motivated by three main driving forces, especially in the telecommunications domain, i.e. time to market, cost reduction and customisations. These market drivers are general forces for component-oriented production and not specific for TINA and distributed systems. However, the authors have identified more detailed and specific problems made with their real TINA middleware implementation. The main problems can be categorized as follows: 1) Simple dependency: a component requires a feature of another component, 2) Version dependency: a component requires another component, but in a specific version, 3) Interoperability conflict: a component cannot be combined with another component, 4) Resource limitation: inside a node or a cluster, a number of resources are only available to a limited extent. Since the knowledge about all the relations and dependencies of the components is very complex it is obvious that it would be helpful to have tool support for the composition, configuration and installation tasks to be performed. This could ensure that the same problem cannot arise twice, since the knowledge is kept reproducibly in the tool.