Middleware

Fig 53 represents the interconnection of components in the OASIS System. The multimedia data itself as well as metadata may be found in their original place in “remote database”. Each remote database has its own structure which is determined by the set of metadata and their interlacing in the charts of relational database. In order to enable a unified → search among all databases connected in the system, a unified structure of metadata had to be defined and mapping from the original set of metadata had to be designed for each database.

Middleware Architecture

DB-Adapter Tier The code which defines mapping and optimises the distant databases to the needs of Middleware can be found in the so-called DB-Adapter. It is a tier which provides a unified and precisely specified interface from one side and understands the structure of a particular distant database from the other side. It follows that for each distant database there is exactly one DB-Adapter identified by a unique URL [Ref. 1]. The access to the interface of the DB-Adapter (as shown in the Fig benext) is effected via HTTP protocol [Ref. 2] , the result of each request is a FLAT file, where each row represents a resource with attributes delimited by space. The interface is described at the Wiki page of the project OASIS [Ref. 3].

CIANT: OASIS Architecture

Reference Material about OASIS Middleware:

• Article about the → Multitier architecture by Viliam Simko.
• Article about the → functionality of the Middleware Software by Mikolaj Leszczuk.
• Learn more about → Middleware- Cache (cache-per-request).
• Read more about → Repository and Asynchronous mechanism of the OASIS Middleware.
• How do → Middleware Queries work?
• That's about → Postprocessing
• Considerations about the → Middleware Interface
• Middleware → Installation and configuration

Metadata

General Information and illustration of the → OASIS Metadata Model.

Partner Databases

The → OASIS Partner Databases are introduced. Their designs vary because of history and institutional requirements.

Database Adapter

The → OASIS Database Adapter is implemented on the partners' databases as a software package and translates their scheme on the shared OASIS Metadata Model.

Platform

The → OASIS Platform forms the Core elements of the OASIS project and presents central aspects of research.

How to participate?

You want to participate in the OASIS Platform and contribute your content to the shared archive? Please follow → this link.

References

• [Ref. 1]: T. Berners-Lee, L. Masinter and M. McCahill. Uniform Resource Locators. 1994,

December, RFC 1738, http://www.ietf.org/rfc/rfc1738.txt.

• [Ref. 2]: R. Fielding, J. Gettys, J. Mogul, H. Frystyk, L. Masinter, P. Leach and T. Berners-Lee.

Hypertext Transfer Protocol -- HTTP/1.1. 1999, June, RFC 2616, http://www.ietf.org/rfc/rfc2616.txt.

• [Ref. 3]: V. Simko, M. Leszczuk and P. Romaniak, DBA-Interface, 2006, http://zkm.oasisarchive.

info/intern/index.php/Communication.