Real Time Open Data (RTOD)

Real Time Open Data (RTOD) is a middleware that provides access to content from different sources though a single access point.

Most current organizations have a heterogeneity of systems, products and back-ends which hold information that is susceptible to be published in Open Data / Open Government Portals. These systems store all the information in different structures using their own metadata, structural/ordering rules, architecture and access mechanisms.

Simple drawing of architecture of OGoov with RTOD and Marmotta

The main problem solved by RTOD is the automatic extraction of content from different kinds of back-ends in order to offer that content in open data catalogs.

Automated content updates

Currently RTOD offers different alternatives for the extraction and automated updating of content through drivers.

Drivers

RTOD drivers are modules that establish communication between the RTOD server and content provider systems (back-ends). These modules are essential in the RTOD architecture as they are in charge of the extraction and update of information. Each driver can access a different content provider system. These are the drivers that are available at the moment:

  • SQL (MySQL, PostgreSQL, Oracle Database, Microsoft SQL Server and Microsoft Access)
  • REST API (XML/JSON)
  • FIWARE (Orion Context Broker)
  • Binary File (e.g. images)

Semantic web

Another main advantage of RTOD is its capability to provide content that is extracted from back-ends as linked and enriched data. RTOD provides content in RDF/XML, Turtle or N3. Moreover, this content can be stored in a Triplestore and accessed through a SPARQL end-point.

Integration with Smart City Platform (FIWARE)

OGoov integrates with the Smart City Platform through its RTOD component and its drivers that provide the necessary tools to obtain the information handled by the platform. It is possible to expose as open data both the snapshot of the real-time data served by Orion Context Broker and the historical data generated by Cygnus (tool for connecting Orion Context Broker with several data storages, HDFS and STH included, in order to create context data historics).

Content reuse

Finally, RTOD also provides a REST API for reusers. This API offers nine different serializations: XML, RDF/XML, N3, TURTLE, JSON-LD, HTML, JSON, CSV and ATOM.