Discourse was down for about a week. I was not immediately aware of this as I was traveling.
Thank you, Mak, for working with the Dreamhost support organization to restore access!
We have not yet entirely reconstructed what took us off line after about 4 1/2 years of service. Maybe a misconfiguration of the Discourse installation finally caused a problem, perhaps during an upgrade of our Dreamcompute hosting environment. We are looking into ways of assuring faster support for Discourse, which is not one of the packages ‘built in’ to our Dreamhost account.