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Most DNS servers provide A/AAAA records in the Additional section of a response, which correspond to the SRV records from the Answer section: ;; QUESTION SECTION: ;_http._tcp.be1.domain.tld. IN SRV ;; ANSWER SECTION: _http._tcp.be1.domain.tld. 3600 IN SRV 5 500 80 A1.domain.tld. _http._tcp.be1.domain.tld. 3600 IN SRV 5 500 80 A8.domain.tld. _http._tcp.be1.domain.tld. 3600 IN SRV 5 500 80 A5.domain.tld. _http._tcp.be1.domain.tld. 3600 IN SRV 5 500 80 A6.domain.tld. _http._tcp.be1.domain.tld. 3600 IN SRV 5 500 80 A4.domain.tld. _http._tcp.be1.domain.tld. 3600 IN SRV 5 500 80 A3.domain.tld. _http._tcp.be1.domain.tld. 3600 IN SRV 5 500 80 A2.domain.tld. _http._tcp.be1.domain.tld. 3600 IN SRV 5 500 80 A7.domain.tld. ;; ADDITIONAL SECTION: A1.domain.tld. 3600 IN A 192.168.0.1 A8.domain.tld. 3600 IN A 192.168.0.8 A5.domain.tld. 3600 IN A 192.168.0.5 A6.domain.tld. 3600 IN A 192.168.0.6 A4.domain.tld. 3600 IN A 192.168.0.4 A3.domain.tld. 3600 IN A 192.168.0.3 A2.domain.tld. 3600 IN A 192.168.0.2 A7.domain.tld. 3600 IN A 192.168.0.7 SRV record support was introduced in HAProxy 1.8 and the first design did not take into account the records from the Additional section. Instead, a new resolution is associated to each server with its relevant FQDN. This behavior generates a lot of DNS requests (1 SRV + 1 per server associated). This patch aims at fixing this by: - when a DNS response is validated, we associate A/AAAA records to relevant SRV ones - set a flag on associated servers to prevent them from running a DNS resolution for said FADN - update server IP address with information found in the Additional section If no relevant record can be found in the Additional section, then HAProxy will failback to running a dedicated resolution for this server, as it used to do. This behavior is the one described in RFC 2782.