Troubleshooting
Troubleshooting information for common issues when running the Data Migrator.
Migration fails to start
- Verify Java 21+: 
java -version. - Check database connectivity and credentials.
 - Ensure Camunda 8 is running and accessible.
 - Review your 
configuration/application.ymlconfiguration. 
Process instances are skipped
- Ensure Camunda 8 process definitions are deployed.
 - Verify 
migratorexecution listeners are added to None Start Events. - Ensure flow nodes exist in both Camunda 7 and Camunda 8 models.
 - Review skipped instance logs for exact reasons.
 
List and retry skipped instances:
./start.sh --runtime --list-skipped
./start.sh --runtime --retry-skipped
Performance issues
- Adjust 
camunda.migrator.page-size. - Ensure database resources are sufficient.
 - Check network latency between components.
 - Monitor CPU/memory/disk usage.
 
Variable migration errors
- Check Camunda 8 variable name restrictions.
 - Verify variable types are supported.
 - Implement a custom 
VariableInterceptorif needed. 
Debug logging
Increase logging levels to get more detail:
logging:
  level:
    root: INFO
    io.camunda.migrator: DEBUG
    io.camunda.migrator.RuntimeMigrator: TRACE
  file:
    name: logs/camunda-7-to-8-data-migrator.log
Cockpit plugin
Plugin not visible in Cockpit
- Ensure the plugin JAR is placed in the correct Camunda 7 plugins directory.
 - Check Camunda 7 logs for any plugin loading errors.
 - Restart Camunda 7 after deploying the plugin.
 
No skip data displayed
- Confirm 
save-skip-reason: trueis set in the migrator configuration. - Verify migration has been run with this setting enabled.
 - Check database connectivity between the plugin and the migrator database.
 
Getting help
- Use the Camunda forum.
 - Search existing issues: https://github.com/camunda/camunda-bpm-platform/issues.
 - When creating a new issue, include: logs, config, environment, steps to reproduce.