If you are a MySQL power user in Korea, its well worth joining the Korean MySQL Power User Group. This is a group led by senior DBAs at many Korean companies. From what I gather, there is experience there using MySQL, MariaDB, Percona Server and Galera Cluster (many on various 5.5, some on 5.6, and quite a few testing 10.0). No one is using WebScaleSQL (yet?). The discussion group is rather active, and I’ve got a profile there (I get questions translated for me).
So from meetups to getting information online, in a quick fashion. Much hunger for open source in Korea, very smart people working there on services feeding the population (where some even make it outside of the local market). The future of open source in Korea is definitely very bright.