> -----Original Message----- > From: Andy Seaborne [mailto:[email protected]] On Behalf > Of Andy Seaborne > Sent: Sunday, January 22, 2012 3:15 PM > To: [email protected] > Subject: Re: Fuseki with SDB not returning any results > > On 22/01/12 15:36, John Fereira wrote: > > Greetings, > > > > I just joined the list but have been working with jena and other > semantic web tools and apps for awhile. I've been trying to get fuseki > running and think I'm really close to what I want to do with it, but > not > quite here. > > > > I'm working with a semantic web application called Vivo > > (vivoweb.org) > which uses a SDB backed with MySQL. I've written a java web app which > manages sparql queries, issues them against a joseki SPARQL endpoint > and > returns the results in multiple formats (basically similar to what elda > is doing.) That's been running in production for over a year but > because > we've run into issues with joseki hanging up (we've got a restart > script > the runs periodically to restart the service) and elda is quite a bit > more robust then the webapp I wrote I'm looking at a elda/fuseki/vivo > configuration that will be used for a project that I am working on for > a > well known UN organization. > > > > I've got an elda/joseki/vivo implementation working and it serves up > LOD datasets fine so far but I'm running into issues replacing joseki > with fuseki. I built a fuseki instance from the 0.2.1-SNAPSHOT > > You can get development builds from > https://repository.apache.org/content/repositories/snapshots/org/apache > /jena/jena-fuseki/ > > It's rebuild nightly if anything changed.
I believe that's where I got the 0.2.0-SNAPSHOT, but then I had to get the SDB and MySQL libraries and put them in the CLASSPATH to get fuseki to start with the SDB additions to the config file. > > > and added > SDB support and MySQL libraries. It starts up without any errors, but > when I access it from elda (or the s-query tool in the fuseki dist), > fuseki is handling the query but returning no results. My test, using > s-tools, looks like this: > > > ./s-query --service http://localhost:3030/ds/sparql 'SELECT * {?s ?p > ?o}' > > > > Which returns: > > > > { > > "head": { > > "vars": [ "s" , "p" , "o" ] > > } , > > "results": { > > "bindings": [ > > > > ] > > } > > } > > > > I can provide a copy of my fuseki "desc" file if necessary but > thought I just check first to see if anyone has any ideas. > > Yes please. > > And are you absolutely sure there is data in the default graph? It's > rather easy to not have data and only find out later. As I said, I can get data out of the same triple store by pointing Joseki an it. In fact, I ripped the SDB/MySQL configuration out of a working joseki configuration almost intact. Here's what my "ttl" file looks like: # begin desc.ttl @prefix fuseki: <http://jena.apache.org/fuseki#> . @prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> . @prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> . @prefix tdb: <http://jena.hpl.hp.com/2008/tdb#> . @prefix sdb: <http://jena.hpl.hp.com/2007/sdb#> . @prefix ja: <http://jena.hpl.hp.com/2005/11/Assembler#> . @prefix : <#> . [] rdf:type fuseki:Server ; # Server-wide context parameters can be given here. # For example, to set query timeouts: on a server-wide basis: # Format 1: "1000" -- 1 second timeout # Format 2: "10000,60000" -- 10s timeout to first result, then 60s timeout to for rest of query. # See java doc for ARQ.queryTimeout # ja:context [ ja:cxtName "arq:queryTimeout" ; ja:cxtValue "10000" ] ; # Load custom code (rarely needed) # ja:loadClass "your.code.Class" ; # Services available. Only explicitly listed services are configured. # If there is a service description not linked from this list, it is ignored. fuseki:services ( <#service1> ) . # Declaration additional assembler items. [] ja:loadClass "com.hp.hpl.jena.tdb.TDB" . # TDB tdb:DatasetTDB rdfs:subClassOf ja:RDFDataset . tdb:GraphTDB rdfs:subClassOf ja:Model . # SDB [] ja:loadClass "com.hp.hpl.jena.sdb.SDB" . sdb:DatasetStore rdfs:subClassOf ja:RDFDataset . sdb:Model rdfs:subClassOf ja:Model . <#dataset> rdf:type sdb:DatasetStore ; ## Number of concurrent connections allowed to this dataset. sdb:store <#store> . <#store> rdf:type sdb:Store ; rdfs:label "SDB" ; sdb:layout "layout2" ; sdb:connection [ rdf:type sdb:SDBConnection ; # Using MySQL sdb:sdbHost "localhost" ; sdb:sdbType "MySQL" ; sdb:sdbName "vivodb" ; sdb:sdbUser "*****" ; sdb:sdbPassword "*******" ; sdb:driver "com.mysql.jdbc.Driver" ; ] . ## --------------------------------------------------------------- ## Vivo dataset in sdb <#service1> rdf:type fuseki:Service ; fuseki:name "ds" ; # http://host:port/ds fuseki:serviceQuery "query" ; # SPARQL query service fuseki:serviceQuery "sparql" ; # SPARQL query service # A separate ead-only graph store endpoint: fuseki:serviceReadGraphStore "get" ; # SPARQL Graph store protocol (read only) fuseki:dataset <#dataset> ; . # end desc.ttl
