I don't like the idea of having separate class, but it seems to be the only way as there are too many API and generics differences.
Nikolay, I would also suggest you extract some super class for continuous query. It will help to avoid code duplicates. As far as remote transformer failure - we should react in the same way as we react now for filter failure. I don't think there should be a difference. What is the reaction now? --Yakov
