The type of pluggable DNS resolver modules for request contexts and custom metadata and wire protocols.
marshal query is a list of context-buffer pairs corresponding to the
channel contexts and request buffers with which to attempt DNS requests.
Requests are made in parallel and the first response to successfully
parse is returned as the answer. Lagging requests are kept running until
successful parse or timeout. With this behavior, it is easy to construct
low-latency but network-environment-aware DNS resolvers.
The type of pluggable DNS server modules for request contexts and custom metadata dn wire protocols.