Continuation-Centric Computing with Arca

This paper presents continuation-centric computing, an op- erating system design paradigm for “serverless”-style work- loads: short-lived tasks that spend a substantial fraction of time waiting on dependencies and other services. Under this paradigm, a running function can capture its current continu- ation—a lightweight snapshot of its state—as a distinct func- tion that can be paused, migrated, or copied as needed. With this ability, functions can expose finer-grained dependency information to providers, enabling more accurate resource allocation and scheduling. This paper evaluates continuation-centric computing using Arca, a new isolation primitive. Arcas are broadly similar to processes in guarantees and isolation, but provide efficient capture and resumption of serializable, portable continuations. As a result, Arcas can serve an order of magnitude more requests per second than current process-based techniques, and perform comparably to in-process isolation techniques.