An experimental, pluggable infrastructure for modular configuration management policy composition

Building a configuration management (CM) system is a difficult endeavor that regularly requires tens of thousands of lines of code to be written. To reduce this effort, several experimental infrastructures have been developed that provide reusable repositories upon which to build a CM system. In this paper, we push the idea of reusability even further. Whereas existing infrastructures only reuse a generic CM model (i.e., the data structures used to capture the evolution of artifacts), we have developed an experimental infrastructure, called MCCM, that additionally allows reuse of CM policies (i.e., the rules by which a user evolves artifacts stored in a CM system). The key contribution underlying MCCM is that a CM policy is not a monolithic entity; instead, it can be composed from small modules that each addresses a unique dimension of concern. Using the pluggable architecture and base set of modules of MCCM, then, the core of a desired new CM system can be rapidly composed by choosing appropriate existing modules and implementing any remaining modules only as needed. We demonstrate our approach by showing how the use of MCCM significantly reduces the effort involved in creating several representative CM systems.