The data management system for the VENUS and NEPTUNE cabled observatories

The VENUS (http://venus.uvic.ca/) and NEPTUNE Canada (http://neptunecanada.ca/) cabled ocean observatories have been envisioned from their inception as underwater extensions of the Internet. Having sensors connected to a network opens up tremendous opportunities, from realtime access to sensor measurements to the interactive control of remote assets. Moreover, with a software system in control, data from all sensors can be managed, archived and made available to the wider community. Finally, a data management system can also offer features that are unique to centrally managed instrumentation: thanks to communication standards, autonomous event detection and reaction becomes a very powerful possibility. This talk will summarize the salient features of DMAS (Data Management and Archiving System) that have been implemented over the past four years as well as the planned features to be delivered soon. DMAS consists of two main components: the Data Acquisition Framework (DAF) takes care of the interaction with instruments in terms of control, monitoring as well as data acquisition and storage. The framework also contains operation control tools. The user interaction features include data search and retrieval, data distribution. Current developments in the Web 2.0 area will provide a complete research environment where users will have the ability to work and interact on-line with colleagues, process and visualize data, establish observation schedules and pre-program autonomous, event detection and reaction. We call this environment "Oceans 2.0". The architecture of DMAS is focused on limiting the amount of data loss and maximizing up time. It is a service oriented architecture, making use of some of the more advanced tools available. The code is written in Java and makes use of an enterprise service bus and of the publish-and-subscribe paradigm. The paper also describes the management approaches that were adopted to build DMAS. Good code quality, the continuous support of VENUS and the need for flexibility in dealing with rapidly changing requirements were the drivers behind the adoption of in-house development, the Agile development methodology and the creation of three teams. The development team deals with requirement collection, analysis, design, coding and unit testing; the QA/QC team performs software tests and regression in a production-like environment. The systems/operations team focuses on the hardware and system software preparation and support, receives and installs new code releases after QA approval and monitors systems operations. We are vying to perform new code releases twice a month. The method has worked well during the four years of the system development phase and has allowed for a constant support of VENUS. DMAS will be completed well under budget.