Future directions of MDSplus

• This paper describes the directions in the evolution of the MDSplus data system.
• It describes three Use Cases in data streaming.
• It shows the performance of MDSplus in local and remote data streaming.
• It describes the main concepts in decoupling data access.
• It presents the last features and tools.

The first version of MDSplus was released in 1991 for VAX/VMS. Since then MDSplus has been progressively adopted in an increasing number of fusion experiments and its original implementation has been extended during these years to cover new requirements and toward a multi-platform implementation. Currently MDSplus is in use at more than 30 laboratories and is being used both for pulsed applications as well as for continuous data streaming for long lasting experiments. Thanks to its large user base, it has been possible to collect requirements driving the evolution of the system toward improved usability and better performance. An important recent feature of the MDSplus is its ability of handling a continuous stream of data, which is readily available as soon at it has been stored in the pulse files. Current development is oriented toward an improved modularity of MDSplus and the integration of new functionality.Improved modularity is achieved by moving away from monolithic implementation toward a plug-ins approach. This has already been achieved recently for the management of remote data access, where the original TCP/IP implementation can now be integrated with new user-provided network protocols. Following a similar approach, work is in progress to let new back-ends be integrated in the MDSplus data access layer. By decoupling the MDSplus data management from the disk data file format it is possible to integrate new solutions such as data cloud without affecting the user Application Programming Interface.