The filter looks good. It is vaguely familiar. I recall seeing similar code in a JavaOne presentation a few years back.
If the init getPersistenceManagerFactory call fails, have you looked at how the error is reported? You have special code to log some configuration errors, but nothing explicit for the getPersistenceManagerFactory call, which in my experience is the most likely API to fail. It might be good to wrap the call with try/catch and log the exception at level SEVERE. If you've already tested that a failure in init does the appropriate logging, you can ignore this.
There are several >80 character lines.