Routing Patterns for Self-Management

This paper contributes towards engineering self-managing systems, starting from known routing schemes. Routing schemes are self-managing, because they create and maintain a set of distributed states in a dynamic environment, enabling service delivery under various constraints. Using the approach of separating the update propagation from the routing table computation in routing protocols, we construct a navigation pattern, which underlies DUAL and OSPF, two known Internet routing protocols. This pattern, called progressive wave, defines a generic information distribution mechanism. We instrument it and show how to collect global statistics about any mechanism using this pattern, and apply these statistics to performance monitoring or troubleshooting. In particular, we demonstrate how the propagation of waves carrying routing updates can be monitored and analyzed. We argue that the progressive wave pattern can be used in self-organizing systems that locate resources under constraints – on the network level, as well as on the service level.