I had a look at the Java code for this action. As you probably already knew, the database connection does not seem to be explicitly closed anywhere.
I do not know how big of an issue this is, and I suspect it may differ for different database drivers.
The solution for this would be to:
Doing this will of course require changes to the database replication module and requires Java knowledge.
As a quick fix you may consider just closing the connection when it is no longer used. http://stackoverflow.com/questions/2225221/closing-database-connections-in-java includes a pattern to do this.