Data-centric Graphical User Interface of the ATLAS Event Index Service

ATLAS EventIndex Service keeps references to all real and simulated ATLAS events. Hadoop Mapfiles and HBase tables are used to store the Event Index data, a subset of data is also stored in the Oracle database. Several user interfaces are currently used to access and search the data. From the simple command line interface, through programmatical API to sophisticated Graphical Web Services. The presentation will describe the most recent, highly interactive Web Service. It provides a dynamic graph-like overview of all available data and data collections. Data are shown together with their relations, ownership, containment or overlaps. Each data entity then gives users a set of actions which are available for the referenced data. Some actions are provided directly by the Event Index system, others are interfaces to various ATLAS services. In many cases, specialised views are offered for detailed data inspection, like several kinds of histograms or Venn diagrams. The presentation will document the current status of the service, its possibilities and performance. The future system evolution as an front-end to the new Event Index Architecture based on the Apache Phoenix will be also described as well as possible extension to more general framework for giving a new, more intuitive access to all experiment data.