A common issue with SDB is that the connection has died: database connections are finite. We recommend that SDB is used with connection pooling which avoids this issue, however that isn't possible with fuseki.
This module doesn't pool connections! However it will check the connection is working and attempt to reconnect if possible.
$ git clone git@github.com:shellac/ReconnectingSDB.git
$ cd ReconnectingSDB
$ mvn install
The jar will be in target/ReconnectingSDB-0.1-SNAPSHOT.jar.
Put the above jar on your classpath (fiddly with fuseki), and use something like the following dataset description:
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix ja: <http://jena.hpl.hp.com/2005/11/Assembler#> .
@prefix sdb: <http://jena.hpl.hp.com/2007/sdb#> .
@prefix jumble: <http://rootdev.net/vocab/jumble#> .
# For use with Joseki.
[] ja:loadClass "net.rootdev.fusekisdbconnect.SDBConnect" .
jumble:SDBConnect rdfs:subClassOf ja:RDFDataset .
<#dataset> rdf:type jumble:SDBConnect ;
jumble:reconnectQuery "SELECT 1" ;
sdb:layout "layout2/index" ;
sdb:connection [
rdf:type sdb:SDBConnection ;
sdb:sdbType "h2:file" ;
sdb:sdbName "DB/H2" ;
]
.