This is imported from bugzilla item http://bugs.mariadb.com/show_bug.cgi?id=587
The fix version in bugzilla is "develop in commit 42b52c6f5153b45a5b1998aca54ca48480ef7514"
If filters and rwsplit are configured as follows, hints don't work.
Changing filters=regex|hints makes it work. This is due to processing order. Regex filter drops hint off.