Numerous CS faculty have demonstrated the benefits of using version control in courses other than software engineering. However, they maintained their own servers, and to the best of our knowledge, none published experiences with version control in CS1 courses for non-CS engineering majors. As a result, even faculty experienced with version control may hesitate to adopt it in some classes, fearing that it is too difficult, time consuming or distracting. In this paper, we describe how we adopted version control in a CS1 course for non-CS engineering majors, and how project hosting services facilitated its use. Our experience indicates that undergraduate engineering majors in CS courses can gain competence in version control, and project hosting services simplify course management.

In recent years, overlay networks have become an important vehicle for delivering Internet applications. Overlay network nodes are typically implemented using general purpose servers or clusters. We investigate the performance benefits of more integrated architectures, combining general-purpose servers with high performance Network Processor (NP) subsystems. We focus on PlanetLab as our experimental context and report on the design and evaluation of an experimental PlanetLab platform capable of much higher levels of performance than typical system configurations. To make it easier for users to port applications, the system supports a fast path/slow path application structure that facilitates the mapping of the most performance-critical parts of an application onto an NP subsystem, while allowing the more complex control and exception-handling to be implemented within the programmer-friendly environment provided by conventional servers. We report on implementations of two sample applications, an IPv4 router, and a forwarding application for the Internet Indirection Infrastructure. We demonstrate an 80x improvement in packet processing rates and comparable reductions in latency.

No abstract

In recent years, overlay networks have become an important vehicle for delivering Internet applications. Overlay network nodes are typically implemented using general purpose servers or clusters. We investigate the performance benefits of more integrated architectures, combining general-purpose servers with high performance Network Processor (NP) subsystems. We focus on PlanetLab as our experimental context and report on the design and evaluation of an experimental PlanetLab platform capable of much higher levels of performance than typical system configurations. To make it easier for users to port applications, the system supports a fast path/slow path application structure that facilitates the mapping of the most performance-critical parts of an application onto an NP subsystem, while allowing the more complex control and exception-handling to be implemented within the programmer-friendly environment provided by conventional servers. We report on implementations of two sample applications, an IPv4 router, and a forwarding application for the Internet Indirection Infrastructure. We demonstrate an 80× improvement in packet processing rates and comparable reductions in latency.