Andrew,
I may have something running and illustrating something. It is not
quite as simple as changing modelFolderDir - ont-policy.rdf has E:/
references, and your description has file:/C:tmp/. I still intermittent
404s where the ont-policy isn't being applied.
I'm not seeing what you see though. I get 404s or concurrent
modification exceptions.
Can we focus on one test case? Which is the simplest? JenaBareThread2
looks closest to below and works (?) for me.
TestJenaBareThreads gives me the exceptions.Is that a suitable focus?
Is the rule reading part necessary to illustrate the problem? Not
knowing this part of the system, reducing to something manageable is
necessary for me.
Andy
On 15/06/15 13:30, Crapo, Andrew (GE Global Research) wrote:
I posted this to users but on second thought maybe this is more
appropriate to dev…
I have multiple clients accessing a common service, which runs in a
multi-threaded environment. Each client will have different scenario
data, e.g., OWL models SC1, SC2, SC3, etc. Each SCi model imports a
common hierarchy of domain models; SCi imports tbox A, which imports
tbox B, which imports tbox C. There is also a rule that inserts a new
triple into an infered model, the object value of which is specific to
the data in the input model SCi.
To validate the thread-safely of the server, I've created a test case
with one or more threads. Each thread accesses concepts in the imported
models via the thread-specific scenario model. That part of the test
code is:
for (int i = 0; i < 50; i++) {
JenaBareThread myThread
= new JenaBareThread();
myThread.start();
}
There are several versions of the run method of JenaBareThread. The one
that works loads one of three scenario data models, which in turn
imports the tbox models, and then queries for the inferred triple and
checks for the correct value for the given scenario. This code is of the
form:
public void run() {
String modelFolderDir =
"file:/C:tmp/DataModels/Shapes/OwlModels";
String abox = modelFolderDir + "/Test"
+ (getInoutidx() + 1) + ".owl";
String ontPolicy = modelFolderDir +
"/ont-policy.rdf";
OntModel dataModel =
ModelFactory.createOntologyModel(OntModelSpec.OWL_MEM);
try {
dataModel.enterCriticalSection(Lock.WRITE);
dataModel.getDocumentManager().setProcessImports(true);
dataModel.read(abox);
}
catch (Throwable t) {
t.printStackTrace();
}
finally {
dataModel.leaveCriticalSection();
}
String rulefn = modelFolderDir +
"/Rule.rules";
List<Rule> ruleList = new
ArrayList<Rule>();
try {
InputStream in =
FileManager.get().open(rulefn);
if (in != null) {
...
(load rule)
}
GenericRuleReasoner
reasoner = new GenericRuleReasoner(ruleList);
reasoner.setDerivationLogging(true);
reasoner.setMode(GenericRuleReasoner.HYBRID);
InfModel infModel =
ModelFactory.createInfModel(reasoner, dataModel);
String askQuery =
"select ?s ?a where {?s <http://sadl.org/Shapes/Shapes#area> ?a}";
QueryExecution
qexec = QueryExecutionFactory.create(QueryFactory.create(askQuery,
Syntax.syntaxARQ), infModel);
ResultSet results =
qexec.execSelect();
... (test results)
}
}
catch (RulesetNotFoundException e) {
e.printStackTrace();
}
catch (HttpException e) {
e.printStackTrace();
}
In this test the scenario models are pre-existing and the multi-threaded
test passes for all threads regardless of the number of threads.
However, I really need to construct each scenario model with data coming
from the client. This I am unable to do without encountering various
errors which apprear to be due to threading issues.
There are 3 other versions of the test, each trying a different way of
creating a scenario model with data not already in an OWL file. For
each, if I run 1 thread the test passes. If I set breakpoints and run
multiple threads, the test passes for each thread. Otherwise I get a
errors. Several of the problems appear to occur when a call is made to
find a concept in one of the imported models. For example, one version
has this in the run method:
long timestamp =
System.currentTimeMillis();
String tsStr = "" + timestamp;
OntModel dataModel =
ModelFactory.createOntologyModel(OntModelSpec.OWL_MEM);
try {
dataModel.enterCriticalSection(Lock.WRITE);
dataModel.setDynamicImports(true);
ReadFailureHandler
rfHandler = new SadlReadFailureHandler(logger);
dataModel.getDocumentManager().setReadFailureHandler(rfHandler );
dataModel.getDocumentManager().setMetadataSearchPath(ontPolicy, true);
dataModel.getDocumentManager().setProcessImports(true);
dataModel.createOntology(aboxNS);
Ontology ont =
dataModel.getOntology(aboxNS);
Resource imp =
dataModel.createResource(ruleNS);
ont.addImport(imp);
OntClass cls =
dataModel.getOntClass(rectNS + "#Rectangle");
Individual inst =
dataModel.createIndividual(aboxNS + "#MyRect", cls);
assertNotNull(inst);
OntProperty height =
dataModel.getOntProperty(rectNS + "#height");
assertNotNull(height);
OntProperty width =
dataModel.getOntProperty(rectNS + "#width");
assertNotNull(width);
String last3 =
tsStr.substring(tsStr.length() - 3);
float w =
Float.parseFloat(last3);
float h = w + 10;
area = h * w;
inst.addProperty(height, dataModel.createTypedLiteral(w));
inst.addProperty(width, dataModel.createTypedLiteral(h));
On a few threads, at least one of the calls to dataModel.getOntClass or
dataModel.getOntProperty returns null. This is because
MultiUnion.graphBaseContains(Triple t) returns false.
The stack trace looks like this:
MultiUnion.graphBaseContains(Triple) line: 132
MultiUnion(GraphBase).contains(Triple) line: 321
MultiUnion(GraphBase).contains(Node, Node, Node) line: 338
OntModelImpl.findByURIAs(String, Class<T>) line: 2873
OntModelImpl.getOntClass(String) line: 908
JenaBareThread3.run() line: 76
Further examination shows that the m_subGraphs ArrayList contains an
incomplete set of imports, sometimes only 2, sometimes 3 and sometimes
the 4 that it should contain. This appears to be the case because the
transitive closure of imports performed by
OntDocumentManager.loadImports does not always load all of the indirect
imports.
I will try attaching a ZIP containing an export of the Eclipse project
containing all tests and the models required. It can be imported into
Eclipse and only the one line setting the location of the
"modelFolderDir" will need adjusting to the path to which the project is
imported. Since my recollection is that attachments here will not work,
I've also shared this ZIP file publicly on Google Drive at
https://drive.google.com/file/d/0B7lXpNc8yGmTWFZZZzRHOWdtZTQ/view?usp=sharing.
Any insight into why this doesn’t work/how to create data models in a
thread-safe manner would be greatly appreciated!
**
*Andrew W Crapo*
Information Scientist
GE Global Research
T +1 518 387-5729
[email protected] <mailto:[email protected]>
One Research Circle
Niskayuna, NY 12302 USA
GE imagination at work
