One option to try would be to use the OWLMicro reasoner configuration:
http://jena.hpl.hp.com/2003/OWLMicroFBRuleReasoner
If that is still too low performance, and if your data is static, then
perform the inference ahead of time, store the inference closure and
serve that without further runtime inference.
Dav
On 02/07/16 10:43, Andy Seaborne wrote:
It is possible that the inference you are using is causing a lot of
calculation. That's driven by what's in sample-dental-ontology-rdfxml.owl.
Andy
On 01/07/16 14:33, Wen, Chen wrote:
Thank you Andy. This machine has 64G memory. Below is the model2
config. Do you see anything wrong?
<#model2> a ja:InfModel;
ja:baseModel
[a ja:MemoryModel ;
ja:content [ja:externalContent
<file:///E:/sample-dental-ontology-rdfxml.owl>]] ;
ja:reasoner
[ ja:reasonerURL
<http://jena.hpl.hp.com/2003/OWLFBRuleReasoner>];
.
-----Original Message-----
From: Andy Seaborne [mailto:[email protected]]
Sent: Thursday, June 30, 2016 4:35 PM
To: [email protected]
Subject: Re: High CPU usage with Apache Jena Fuseki
On 30/06/16 18:51, Wen, Chen wrote:
Hi,
I am having a problem with fuseki-server. Every time when I try to do
an ontology based query or just click on "count triples in all
graphs", the CPU runs on almost 100% and hangs there. I have to
terminate the process to get CPU usage back down.
I have a customized config.ttl for tdb:
<#tdb> rdf:type fuseki:Service ;
fuseki:name "tdb" ; # http://host/inf
fuseki:serviceQuery "sparql" ; # SPARQL query
service
fuseki:serviceQuery "query" ; # SPARQL query
service (alt name)
fuseki:serviceUpdate "update" ; # SPARQL update
service
fuseki:serviceUpload "upload" ; # Non-SPARQL
upload service
fuseki:serviceReadWriteGraphStore "data" ; # SPARQL Graph
store protocol (read and write)
# A separate read-only graph store endpoint:
fuseki:serviceReadGraphStore "get" ; # SPARQL Graph
store protocol (read only)
fuseki:dataset <#dataset2> ; #select which set to
.
tdb:GraphTDB rdfs:subClassOf ja:Model .
<#dataset2> rdf:type ja:RDFDataset ;
ja:defaultGraph <#model2>;
.
Where does <#model2> go to in the config?
And I also increased JVM memory as below in fuseki-server.bat:
java -cp jena-tdb-3.1.0.jar:jena-arq-3.1.0.jar -Xms1g -Xmx15g
-XX:NewSize=4g -XX:MaxNewSize=4g -XX:SurvivorRatio=8 -jar
fuseki-server.jar %*
Only -jar is needed, not -cp
How big is the physical RAM in the machine?
If it is say 16G, then -Xmx15g is not a good idea as it may force the
OS to swap the java heap.
For TDB, much of the caching is off heap so -Xmx15g detracting from
that. Allow 2G per TDB database + 2G for Fuseki.
I have only 124 tuples loaded. And It works if I do a query without
any specific criteria like:
select ?s ?p ?o
where
{
?s ?p ?o .
}
limit 100
However if I do a simple ontology specific query, the CPU goes up
high and cannot recover anymore:
SELECT ?patient
WHERE
{
?patient <http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<http://sample.org/dental-ontology/RIDO_0000083> .
}
limit 100
Am I missing anything? Can somebody advise?
