This page discusses some tips to troubleshoot issues with Virtual Graphs.
The most common problem with virtual graphs is configuring the mappings correctly. Each database has different casing behavior, quoting characters, etc. The following features can be helpful when troubleshooting these issues.
Enable Debug Logging
Stardog uses log4j2 for logging. You can enable debug logging at the virtual graph level by adding this line to the
Loggers section of your
<Logger name="com.complexible.stardog.virtual" level="DEBUG" additivity="false"> <AppenderRef ref="stardogAppender"/> </Logger>
This will increase the logging to the
stardog.log file (but not to the console).
See our section on Logging for more information on how to configure your
Metadata Inspection Tool
You can use the metadata inspection tool to retrive the schema and column names as they appear to Stardog when connecting using the the virtual graph connection properties (driver name, connection string, credentials, etc.). The inspection tool is accessed using the command-line interface (CLI). The documentation is accessed using the help command:
$ stardog-admin help source_metadata
Alternatively, see the
virtual source_metadata manual page in the Stardog Admin CLI Reference Manual.
The metadata insepction tool is for JDBC-type data sources only. Also, it is a client-side application. It does not connect to Stardog but connects to the backing database directly, so it is possible for there to be different firewall, class-loading, or other issues than Stadog will encounter.