SolidWallOfCode opened a new pull request #7843: URL: https://github.com/apache/trafficserver/pull/7843
In situations where DNS is lightly used, or when there is only one FQDN requested, if a nameserver fails there is no failover to another nameserver. The underlying cause is recovery depends on actions triggered from `DNSHandler::mainEvent`. This means if a nameserver fails on a request, it takes another request for a different FQDN to trigger recovery. In a sidecar situation where only one FQDN is every requested, new requests for that FQDN stack up on the collapsing queue for the failed nameserver and ATS appears to become unresponsive. This fix makes sure that if there is a nameserver failure, `DNSHandler::mainEvent` is invoked at least once after the failure. If that happens, recovery becomes self sustaining recovery actions cause subsequent invocations of `DNSHandler::mainEvent`. -- 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]
