elsloo opened a new issue #7988: URL: https://github.com/apache/trafficserver/issues/7988
Currently, it appears that at the very least, the no answer, no error, implicit negative response from an authoritative DNS server is not cached by HostDB. These answers are also known as a `NODATA` response per RFC 2308, section 2.2, found here: https://datatracker.ietf.org/doc/html/rfc2308#section-2.2 At a minimum, HostDB should implement negative caching for this case, but other cases, such as `NXDOMAIN` should also be implemented if missing. Ideally the existing implementation would be analyzed against the negative caching RFC linked above, and any gaps would be rectified. Without the ability to cache negative answers such as the `NODATA` response, two negative things occur: 1. HostDB will hammer its configured caching resolver with queries that cannot be satisfied 2. Response time of incoming requests may be affected depending on how ATS is configured; for example, when client address family matching is enabled via `proxy.config.hostdb.ip_resolve` and the upstream host lacks an `AAAA` record. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected]
