I use HSQLDB on OSGI framework. And it is common solution to use pax-logging that support many logging frameworks (java logging, slf4j, jboss logging etc).
I don't have problems with pax-logging, however, I have problems with HSQLDB logging messages. HSQLDB logging component is very tricky - some messages go to pax-logging system, some go to console.
Could anyone explain what messages where must go and why.
There are separate logging components in HSQLDB.
The Server uses separate writers for log and error messages. The logs default to stdout and stderr but you can set each one to use a custom PrintWriter.
The optional SQL log is always a file. It can be turned on and off live for checking the SQL statements being executed.
The optional event log is a file or an external logging framework. The latter is used when the database is in-process in an application. In both configurations, it reports general persistence events at different levels of detail selected by the user.