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https://github.com/benhid/nora
Spark-based OWL reasoner
https://github.com/benhid/nora
apache-spark nosql owl-reasoner owlapi
Last synced: 25 days ago
JSON representation
Spark-based OWL reasoner
- Host: GitHub
- URL: https://github.com/benhid/nora
- Owner: benhid
- License: mit
- Created: 2023-01-09T12:21:09.000Z (almost 2 years ago)
- Default Branch: main
- Last Pushed: 2024-06-06T05:54:57.000Z (7 months ago)
- Last Synced: 2024-06-06T07:12:03.380Z (7 months ago)
- Topics: apache-spark, nosql, owl-reasoner, owlapi
- Language: Java
- Homepage: http://benhid.com/nora/
- Size: 291 KB
- Stars: 1
- Watchers: 1
- Forks: 0
- Open Issues: 1
-
Metadata Files:
- Readme: README.md
- License: LICENSE
- Citation: CITATION.cff
Awesome Lists containing this project
README
# NORA: Scalable OWL reasoner based on NoSQL databases and Apache Spark
[](LICENSE)
Tested with [OpenJDK 11](https://docs.aws.amazon.com/corretto/latest/corretto-11-ug/generic-linux-install.html) and Gradle 7.5.1.
Cite us:
> _Benítez-Hidalgo A, Navas-Delgado I, Roldán-García MM. NORA: Scalable OWL reasoner based on NoSQL databases and Apache Spark. Softw Pract Exper. 2023; 53(12): 2377–2392. doi: 10.1002/spe.3258_
## Building the project
Use `gradle` to build the project:
```bash
$ make build
```
## Getting started
Before running the project, edit the [`config.properties`](config.properties) and set your own values. Make sure to set the `NORA_CONFIG` environment variable to the path of the `config.properties` file:
```bash
$ export NORA_CONFIG=$(pwd)/config.properties
```
Load the ontology into the database:
```bash
$ java -cp nora.jar loader.Loader examples/ontology.owl examples/individuals/ http://w3id.org/examples/ontology.owl
```
Then, start the reasoning process by running the following command:
```bash
$ java -cp nora.jar reasoner.Reasoner
```
or by using `spark-submit`:
```bash
$ spark-submit \
--name nora \
--class reasoner.Reasoner \
--master spark://host:port \
--driver-memory 6G \
--executor-memory 120G \
file:///home/user/nora.jar 10
```
A step-by-step guide is available [here](GETTING_STARTED.md).
## Troubleshooting
#### Exception `java.lang.OutOfMemoryError: Java heap space` when running Apache Spark in client mode
The flag `-Xmx` specifies the maximum memory allocation pool for a Java Virtual Machine (JVM), while `-Xms` specifies the initial memory allocation pool. These flags can be set to modify the Java memory settings:
- IntelliJ IDEA: Run/Debug configuration > Set VM options to `-Xms10g -Xmx80g`
- Terminal: Run Java with `-Xms10g -Xmx80g`
## Tests
Run the following command to run the tests:
```console
$ make test
```
Embedded Cassandra requires JDK 11 or lower. If using a higher version, downgrade it to JDK 11.
## License
This project is licensed under the MIT license - see the [LICENSE](LICENSE) file for details.