  We present a current status of data center based on KCDC (KASCADE Cosmic Ray
Data Centre), which was originally designed for providing an open access to the
events measured and analyzed by KASCADE-Grande, a cosmic-ray experiment located
in KIT, Karlsruhe. In the frame of the German- Russian Astroparticle Data Life
Cycle Initiative we extend KCDC in order to provide an access to different
cosmic-ray experiments and make possible aggregation and joint querying of
heterogeneous air-shower data. In the present talk we discuss the description
of data and metadata structures, implementation of data querying and merging,
and first results on including data of experiments located in Tunka, Russia, in
this common data center.
