Ankur and Mari Sahu Assistant Professor Raja Sambasivan’s research supports innovation in the cloud ecosystem — i.e., cloud data centers, distributed systems within data centers, and wide-area networks that connect data centers.   His research involves creating sophisticated debugging tools for distributed systems, as the immense difficulty of diagnosing problems dis-incentivizes innovation. It also involves building distributed systems that are easily evolvable to support innovation. Sambasivan's current research efforts focus on: 1) Creating an instrumentation framework for distributed systems that automatically searches the space of possible instrumentation choices to enable that needed to provide visibility into a new problem and 2) Creating powerful abstractions for diagnosing problems in distributed systems that are at least as powerful as the API-based abstractions developers use to build them.  In the past, Sambasivan and his collaborators created D-BGP, a version of BGP augmented with evolvability features to support the deployment of new inter-domain routing protocols. He also developed one of the earliest distributed-tracing infrastructures strongly suited for performance diagnosis tasks and a diagnosis toolkit called Spectroscope that builds on tracing to diagnose performance degradations in distributed systems.