The previous implementation would redirect a query to a failed server
based on a timeout and random chance per query. This could lead to
issues of having to deal with server timeout scenarios when the server
isn't back online yet causing latency issues. Instead, we should
continue to use the known good servers for the query itself, but spawn a
second query with the same question to a different downed server. That
query will be able to be processed in the background and potentially
bring the server back online.
Also, when using the `rotate` option, servers were previously chosen at
random from the complete list. This PR changes that to choose only from
the servers that share the same highest priority.
Authored-By: Brad House (@bradh352)
We have been missing basic documentation on some of the features
in c-ares for a while. This document should be used to document any
features that need explanation for behavior analysis and how to use
said feature.
Authored-By: Brad House (@bradh352)