  Input data for applications that run in cloud computing centres can be stored
at distant repositories, often with multiple copies of the popular data stored
at many sites. Locating and retrieving the remote data can be challenging, and
we believe that federating the storage can address this problem. A federation
would locate the closest copy of the data on the basis of GeoIP information.
Currently we are using the dynamic data federation Dynafed, a software solution
developed by CERN IT. Dynafed supports several industry standards for
connection protocols like Amazon's S3, Microsoft's Azure, as well as WebDAV and
HTTP. Dynafed functions as an abstraction layer under which protocol-dependent
authentication details are hidden from the user, requiring the user to only
provide an X509 certificate. We have setup an instance of Dynafed and
integrated it into the ATLAS data distribution management system. We report on
the challenges faced during the installation and integration. We have tested
ATLAS analysis jobs submitted by the PanDA production system and we report on
our first experiences with its operation.
