Armada: a reference model for an evolving database system

The current database deployment palette ranges from networked sensor-based devices to large data/compute Grids. Both extremes present common challenges for distributed DBMS technology. The local storage per device/node/site is severely limited compared to the total data volume being managed and the local processing power is too limited to handle a high query load. In this paper, we propose Armada: a novel reference model for a distributed database architecture to facilitate evolutionary growth. Participating systems can autonomously decide to take responsibility in the distributed data management task. The system adapts to varying workloads and supports dynamic system re-sizing, e.g. growing and shrinking of the system at large. Armada uses lineage trails to capture the metadata and history. Lineage trails from the basis to direct updates to the proper sites, break queries into multi-stage plans, and provides a reference point for site consistency. The lineage trails are managed in a purely distributed way, each Armada site is responsible for their persistency and long term availability. They provide a minimal, but sufficient basis to handle all distributed query processing tasks. The analysis of the Armada reference architecture depicts a path for innovative research at many levels of a DBMS