Caching techniques for use in a computer system comprising a core and at least one edge device. The core comprises at least one object addressable storage system. At least one cache is disposed logically between the core and the at least one edge device. The cache has a replacement policy that selects from among the content units in the cache based upon at least one replacement criterion selected from the group consisting of: an identity of a source that wrote an evaluated content unit; when the replacement is performed subsequent to a request to access at least one content unit, an identity of a requestor that issued the request; a size of an evaluated content unit; a content type of an evaluated content unit; and when metadata was written along with an evaluated content unit, the substance of the metadata.