Opencm: Early Experiences And Lessons Learned

OpenCM is a configuration managment system that supports inter-organizational collaboration, strong content integrity checks, and fine-grain access controls through the pervasive use of cryptographic naming and signing. Released as an alpha in June 2002, OpenCM is slowly displacing CVS among projects that have high integrity requirements for their repositories. The most recent alpha version is downloaded 45 times per day (on average) in spite of several flaws in the OpenCM's schema and implementation that create serious performance difficulties.Since the core architecture of OpenCM is potentially suited to other archival applications, it seemed worthwhile to document our experiences from the first year, both good and bad. In particular, we review the original OpenCM schema, identify several flaws that are being repaired, and discuss the ways in which cryptographic integrity has influenced the evolution of the design. Similar design issues seem likely to arise in other cryptographically checked archival storage applications.