PowerDNS and dnsdist Prometheus Metrics Discrepancy

[v0tti]

Hi everyone,
I've been working with PowerDNS and dnsdist, and I've noticed a significant difference between the dnsdist_responses and pdns_auth_backend_queries Prometheus metrics. Even though caching in dnsdist is disabled, the rate of dnsdist responses is higher than the rate of PowerDNS queries. I'm curious to understand the reasons behind this discrepancy.

[Habbie]

The backend-queries metric in the Authoritative server counts queries sent by PowerDNS to the database backend. This number can be higher than the number of DNS queries answered (because we may need multiple pieces of information from the database to answer one query), or lower (because the auth also has caches in several places).

I suspect pdns_auth_tcp_answers + pdns_auth_udp_answers should come closer to dnsdist_responses

[v0tti]

Thanks for the explanation. pdns_auth_tcp_answers + pdns_auth_udp_answers works out to pretty much the same as dnsdist_responses.