1.0.0

HA Cluster

The master/slave architecture of the cluster allows it to scale horizontally by introducing more workers and also ensures availability. We call the master 'Coordinator' and the slave nodes 'Workers'.

Coordinator

• Load balances /extract requests
• Load balances dictionary updates
• Manages update feeds
• Manages worker dictionary queries

Worker

• Keeps track of its dictionaries fingerprint
• Creates a pool of pipelines
• Serves extraction requests
• Ability to update it's Gazetteer and Metadata PR SPARQL queries
• Ability to reload the whole pipeline dictionary

Dynamic updates

• Multiple retries on failed update, full dictionary reload is triggered after a limit is hit (configurable)
• EUF plug-in keeps track of updated entities and serves changelists through special SPARQL queries
• Updates are kept track of via GraphDB's fingerprints