InternalReasonerException: Datatype ranges cause exception in backtracking

[galigator]

InternalReasonerException: Datatype ranges cause exception in backtracking

[greeny277]

I built the package from the sources and included it into my project. The error hasn't reappeared yet 👍

[Galigator]

Interesting, I will try to reproduce.

[Galigator]

Thx for this bigger ontology and for the analyse on 'randomizeAxioms()'.

I have hack into the ontology and SearchMinimalBug, I can now achieve a 85% bug occurrence on sub-set of your ontology. Baddly this sub set still have more than 1000 axioms.

So I have hack SearchMinimalBug a little more to optimize number of axiom and bug occurrence.

85% is enough to start investigation.

[Galigator]

The last commit should solve the problem.

There was a problem in the way of backjump when multiple branch are related to clash with dependencies on branch that haven't been explore when backtracking.

The way I resolve it should not mark an inconsistent ontology as consistent, but it may consider inconsistent ontologies that should be consistent if there was any bug.

[greeny277]

Interesting, I will try to reproduce.

Thanks .

If you can't reproduce it I would share my ontology with you.

[Galigator]

I failed at reproduce it.

[greeny277]

I think I might have found the root of the problem.

When I use two equivalent classes with the same data range limit it crashes although they are not marked as disjoint:

For instance. the following causes a crash:

NormalDose = 
(concreteDrug some Clozapin)
 and (dose some xsd:integer[>= 100 , <= 250])

MaximumDose=
(concreteDrug some Clozapin)
 and (dose some xsd:integer[>= 250 , <= 251])

When I increase the limit by 1 in the second class, it doesn't fail.

[greeny277]

Perhaps you can reproduce this error now.

[Galigator]

Okay, even with this information I failed to reproduce the bug. See the test programs TestBasic.java.

So to show the bug we may use another strategy, I just write a small program that take an ontology that cause a crash/exception and search for a minimal set of axioms that produce the crash/exception; and it rename every entities in it.

This program can be use the following way :

git clone https://github.com/Galigator/openllet.git
cd openllet/tools-pellint/
./searchMinimalBug.sh /path/to/the/problematic/ontology/file.owl

(it use maven compile then run)

The program use a random strategy and all yours cpu to search a sub-ontology that create the crash.
The found sub-ontology is put into the file "minimalOntologyFile.owl".

The program is 'any-time' (aka it can be stop any time with an ontology that is smaller that your original ontology, once it have check consistency at least one time); because it is random based, you can run it on many computer as you have.

[greeny277]

Yet I'm unable to build your project.

For Opennllet Version 2.6.4-SNAPSHOT I get the error:

[ERROR] Failed to execute goal on project openllet-pellint: Could not resolve dependencies for project 
com.github.galigator.openllet:openllet-pellint:jar:2.6.4-SNAPSHOT: The following artifacts could not be 
resolved: com.github.galigator.openllet:openllet-jena:jar:2.6.4-SNAPSHOT, 
com.github.galigator.openllet:openllet-owlapi:jar:2.6.4-SNAPSHOT: Could not find artifact 
com.github.galigator.openllet:openllet-jena:jar:2.6.4-SNAPSHOT -> [Help 1]

After switching to version 2.6.3 another error occurs:

[WARNING]
java.lang.ClassNotFoundException: openllet.pellint.SearchMinimalBug
        at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
        at org.codehaus.mojo.exec.ExecJavaMojo$1.run(ExecJavaMojo.java:270)
        at java.lang.Thread.run(Thread.java:748)

[ERROR] Failed to execute goal org.codehaus.mojo:exec-maven-plugin:1.6.0:java (default-cli) on project openllet-pellint: An exception occured while executingthe Java class. openllet.pellint.SearchMinimalBug -> [Help 1]
org.apache.maven.lifecycle.LifecycleExecutionException: Failed to execute goal org.codehaus.mojo:exec-maven-plugin:1.6.0:java (default-cli) on project openllet-pellint: An exception occured while executing the Java class. openllet.pellint.SearchMinimalBug
        at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:212)
        at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:153)
        at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:145)
        at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:116)
        at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:80)
        at org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build(SingleThreadedBuilder.java:51)
        at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:128)
        at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:307)
        at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:193)
        at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:106)
        at org.apache.maven.cli.MavenCli.execute(MavenCli.java:863)
        at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:288)
        at org.apache.maven.cli.MavenCli.main(MavenCli.java:199)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:498)
        at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:289)
        at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:229)
        at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:415)
        at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:356)
Caused by: org.apache.maven.plugin.MojoExecutionException: An exception occured while executing the Java class. openllet.pellint.SearchMinimalBug
        at org.codehaus.mojo.exec.ExecJavaMojo.execute(ExecJavaMojo.java:339)
        at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:134)
        at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:207)
        ... 20 more
Caused by: java.lang.ClassNotFoundException: openllet.pellint.SearchMinimalBug
        at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
        at org.codehaus.mojo.exec.ExecJavaMojo$1.run(ExecJavaMojo.java:270)
        at java.lang.Thread.run(Thread.java:748)

Any suggestions?

[Galigator]

The SearchMinimalBug is a program I add Saturday morning, so it is only available in the 2.6.4-SNAPSHOT.

Maybe you need to build the project first.
On the openllet project root do :

mvn clean install -DskipTests=true

before going into tools-pellint/. It should take less than a minute.

[greeny277]

Ok this is the resulting minimal ontology.

[greeny277]

Could you reproduce the error with the minimal ontology?

[Galigator]

Sorry for this late answer, I have try your ontology but it look good (didn't throw exception or any crash).
Do you have a configuration file with options for pellet ?

[greeny277]

No i don't have any config files for pellet as far as i know...
I also tried reasoning the minimal ontology and i don't get an error either?! This is so weird.
Would you mind trying this bigger ontology with SearchMinimalBug.java for a few seconds? Just to see if you get any errors at all. I tried reasoning the linked ontology as well without removing axioms and it turns out that the randomizeAxioms() functions determines if does crash or not.

[greeny277]

I'm glad that you were able to reproduce the error. I looked up the source code where the error is thrown. These backtracking algorithms are no fun to debug by only staring at the code I can tell. If you will be able to obtain a smaller ontology feel free to share it so I can help debugging.
Thx for your effort anyway!

[greeny277]

That sounds great. When will the openllet 2.6.4-SNAPSHOT repository contain this fix so I can try it?

[greeny277]

Shall I close the issue?

[Galigator]

You are welcome.