Hi,
When I set the level for a category, all the subcategories will use that same level as this is a hierarchical configuration.
For example, if you do:
```
CALL LOGCONTROLLER('com.denodo', 'INFO')
```
All the classes under "com.denodo" category will write in the log file using the “INFO” level. Then, categories like "com.denodo.cache" which is a subcategory of "com.denodo" will also log in "INFO" mode.
If I had an error and I am not sure about what log category I should enable, I usually change "com.denodo" log category. Then by reading the logs, I can see subcategories displaying the information I am looking for and I can change the log level only for the category that is required to change.
I would like to suggest you some log categories to debug specific parts of Virtual DataPort server:
* "com.denodo.cache": to get information about cache.
* "com.denodo.engine.storedprocedure": To see log messages of stored procedures.
* "com.denodo.engine.threads": To show debug information of the pool of threads.
* "com.denodo.engine.wrapper.raw.[datasourceType]": To get the data source access information. DatasourceType could be arn, df, gs, html (itpilot), jdbc, json, ldap, my (custom), odbc, ws, or xml.
* "com.denodo.engine.swap" : To get information about swap.
I would also suggest you to refer the community answer “[How to determine log controller status](https://community.denodo.com/answers/question/details?questionId=90670000000Xd6sAAC&title=How+to+determine+log+controller+status) ” to know about changing the level log for a category.
Hope this helps.