An approach to build high-performance OPC-XML DA server system based on MONGODB and Comet

A simple implementation for OPC XML-DA has been achieved by the traditional XML-DA server. However, little has been attracted to the design and improvement of the capability. An OPC-XML DA server system of high performance is designed in this paper. We use .net asynchronous framework to design asynchronous subscription mechanism which is based on the Comet. New caching mechanism is designed by non-relational database such as MongoDB. Historical data storage is achieved based on the raw data compression method. Through a set of testing, we found that this system greatly improve the ability under high concurrency and high volume of data.