Comment 7 for bug 1288528

Ok, good point about that wsrep_desync is global. The problem is now, if wsrep_desync is already ON, should we allow SET GLOBAL wsrep_desync=ON again (since as you said it should be idempotent)? Or should we block? Or return error?
(of course when SST is going on any wsrep_desync modification must be forbidden, but should it be forbidden when just two clients request wsrep_desync=ON independently? I think it should, but some may argue.)