Hi Alessandro On 01.02.2012, at 19:19, Alessandro Adamou wrote: > > I tried to add a MusicBrainz Referenced Site (the one maintained by DBTune) > using the following configuration: > > id = musicbrainz > name = musicbrainz > entity prefixes = > http://dbtune.org/musicbrainz/resource/ > http://dbtune.org/musicbrainz/resource/artist/ > http://dbtune.org/musicbrainz/resource/record/ > http://dbtune.org/musicbrainz/resource/track/ > http://dbtune.org/musicbrainz/resource/master/
Parsing "http://dbtune.org/musicbrainz/resource/"; would be enough as it will be matched as "http://dbtune.org/musicbrainz/resource/*";. > access URI = http://dbtune.org/musicbrainz/data/ > dereferencing = coolURI > query service = http://dbtune.org/musicbrainz/sparql > query strategy = SPARQL > caching strategy = used > cache name = mbcache > > I then went on to query the site for the artist Metallica, first in json > > curl -H "Accept: application/json" > "http://localhost:8080/entityhub/site/musicbrainz/entity?id=http://dbtune.org/musicbrainz/resource/artist/65f4f0c5-ef9e-490c-aee3-909e7ae6b2ab"; > > then in rdf+xml > > curl -H "Accept: application/rdf+xml" > "http://localhost:8080/entityhub/site/musicbrainz/entity?id=http://dbtune.org/musicbrainz/resource/artist/65f4f0c5-ef9e-490c-aee3-909e7ae6b2ab"; > > I noticed that the rdf/xml graph as many, many more triples. More precisely, > it includes inverse predicates, namely triples like > > ?x foaf:maker > http://dbtune.org/musicbrainz/resource/artist/65f4f0c5-ef9e-490c-aee3-909e7ae6b2ab > The entityhub does not support incoming triples. Therefore it is expected that those are missing in the Entityhub specific "application/json" serialization. If you choose a RDF backed serialization such triples may be present if the remote service returns them. This may be the case for the "coolURI" dereferencer. > I haven't checked if there is anything else missing yet. I would expect all incoming triples are "missing". If you just look at outgoing the two serialization should represent the same information. > > Is this some limitation of the json-ld renderer or something? > Note that the "application/json" returned by the Entityhub is NOT json-ld but an own JSON serialization. > Also, with this cache strategy am I not supposed to get the same data when > querying the entity hub tout-court? If I issue: > > curl -H "Accept: application/json" > "http://localhost:8080/entityhub/entity?id=http://dbtune.org/musicbrainz/resource/artist/65f4f0c5-ef9e-490c-aee3-909e7ae6b2ab"; > From the cache you will get no incoming triples regardless of the chosen Accept mime type. This is simple because incoming triples will not get stored in the cache. > I keep getting a 404 Have you configured a Yard and a Cache with the name "mbcache" as noted in the above configuration? best Rupert
