Basically question is in the title.
Can we setup a resolver to not do continuous resolution unless DNS does not resolve?
Once we get a resolution is it possible to cache this forever (until a restart) like we do without a resolver?
Looking at the configuration we can only specify a timeout to have the DNS check for up/down. Configuration | Configuration Section Basics | Resolvers | HAProxy Enterprise 2.6r1
But we would only like DNS to check when we are down and once we are up stop doing DNS resolution.