Catena: A distributed architecture for robust service function chain instantiation with guarantees
Flavio Esposito · 2017
The service function chain paradigm links ordered service functions via network virtualization, in support of applications with severe network constraints. This paradigm is particularly interesting in (federated) scenarios where is beneficial to decouple heavy processing from the core cloud and distributed it closer to end-users, such as in edge clouds. To provide such wide-area (federated) virtual network services, a distributed architecture should orchestrate processes to allow instantiation and maintenance of virtual paths hosting service function chains, while guaranteeing performance and fast convergence, even in presence of failures. To this end, we propose Catena, an architecture for resilient distributed service function chain instantiation. To instantiate a service chain, Catena uses a fully distributed asynchronous consensus mechanism that has bounds on convergence time and guarantees an optimal (1-1/e)-approximation with respect to the Pareto optimal centralized chain instantiation, even in presence of (non-byzantine) failures. We leverage stochastic optimization theory to design Catena, and we evaluate its performance and policy tradeoffs with simulations and on a (released) prototype implementation, finding surprising results and demonstrating policy programmability for the resilient distributed chain instantiation problem.