Adaptation Models for Network-Aware Distributed Computations

service they receive from the network. This allows the application to execute well over a diverse set of networks and under a wide range of network conditions. However, network diversity and dynamic network conditions make the development of network-aware applications a difficult task, since the developer has to be an expert in both the application domain and networking. In this paper we look at a number of network-aware applications and identify three adaptation strategies that have proven to be effective. These strategies can be viewed as adapation models that capture the essential structure of the adaptation process. Similar to the use of programming models in parallel and distributed computing, adaptation models can be used to guide the development of other network-area applications and they can also form the basis for programming support, e.g. middleware, that supports the development of network-aware applications. We describe these three adaptation models, compare their features and applicability, and briefly discuss how these models impact the design of middleware that supports network-aware applications