LIDEN framework allows monitoring the dynamism of the linked data space in terms of SPARQL queries. LIDEN combines pull and push approaches while monitoring the changes of SPARQL queries over the linked data space. For this purpose, it extends CArtAgO environment infrastructure with semantic workspace and semantic artifact concepts. Semantic workspaces allow developer for creating linked data clouds for an application using VoID descriptions of datasets. In the context of a semantic workspace, semantic artifacts provides means for monitoring SPARQL queries by pulling their results periodically and notifying the application if there is any change. For transparent distribution of queries in the environment, WoDQA federated linked data query engine is incorporated into the infrastructure.
LIDEN can be used via maven dependency as seen below.
From the application development perspective, an application knows what data to monitor and can accordingly define the SPARQL queries to be monitored. Thus, here a push mechanism is needed. Using the push mechanism, the application registers the SPARQL queries that will be monitored to the infrastructure and then waits for being notified in case of a change. This push mechanism constitutes the application side interface of the proposed infrastructure. The hybrid approach of combining pull and push simplifies the interaction of developers with the linked data space, since developers only need to submit their SPARQL queries to the monitoring infrastructure without a need for specifying the datasets on which the query parts would be executed.