I had tried the obvious answer (“localhost”) before posting to the KB.
Several contributors confirmed that answer is correct (Giovanni, nomore340, Kyle Ross and David). Thank you.
I can, after finding I had a masked error in the live code (since fixed), confirm that this works.
[Aside] I’m not trying to gyp people out of “Star Points” for their answers, it’s just that I cannot approve answers. I have submitted a trouble ticket about this problem.
Answer #1
For most if not all site5 servers the hostname for your mysql settings is “localhost”