Export a data subset to a remote site
Butler should provide the functionalities to identify a data subset based on metadata and to extract it in a format suitable for data exportation
Guarantee that a butler data tree in a given site is identical as a reference one
Given the fact that the LSST data will be available in several sites, we need to be able to guarantee that a dataset in a given site is identical to the one in another site.
Mechanism to mark data as invalid or obsolete
There should be a mechanism to mark a dataset as invalid or obsolete. Ideally flis flag should be propagated to any official remote site