Data Aggregation In The Astroparticle Physics Distributed Data Storage

German-Russian Astroparticle Data Life Cycle Initiative is an international project whose aim is to develop a distributed data storage system that aggregates data from the storage systems of different astroparticle experiments. The prototype of such a system, which is called the Astroparticle Physics Distributed Data Storage (APPDS), has been being developed. In this paper, the Data Aggregation Service, one of the core services of APDDS, is presented. The Data Aggregation Service connects all distributed services of APPDS together to find the necessary data and deliver them to users on demand.