Development of Unified Data Access Layer
The CROSSGRID project addressed large-scale problems that required a new approach to computing. It has created new Grid components for interactive and data intensive applications such as simulating surgical procedures, and analysis of data in high-energy physics. The project developed the Unified Data Access Layer (UDAL), which provides a flexible system for storage nodes and data centres. At present the UDAL is only used for estimating the data access latency and bandwidth of internal storage nodes. However, it is capable of being adapted to many different uses. The current version of UDAL comes with components for estimating the cost of data access for information held in secondary and tertiary storage. UDAL's goal has been to make access to grid storage much simpler and more efficient. UDAL is a framework containing plugins known as cecomponents. These are placed into categories according to the different services offered. UDAL is a universal platform which can be used for different purposes. These can be achieved by simply writing new cecomponents or modification of built-in expert system rules. It can also adopt new data storing and service devices. Cecomponents can now be developed in almost any programming language, which is a major technological advance. One of the greatest benefits of using UDAL is its ability to adapt to new storage devices. This is possible even if they were not taken into account during the development of UDAL. Users create their own cecomponents which can be used immediately after the plugins have been registered using UDAL tools.
