My workload sends lots of queries to various TLDs and public suffix 2LDs (.co.uk, ...), but non-infrastructure queries to leaf domains are almost not repeated sufficiently often to be found in the cache.
How should I tune the cache? Ideally, (but unbound likely can't do this), the NS/A/AAAA/DNSKEY records of domains that have delegated sub-domains would be cached in a separate cache (maybe even a separate max-ttl) from the cache that handles "leaf" domains. In the mean time I probably need a medium-sized infra cache and a small data cache? Not quite sure how to tune a nameserver whose dominant client walks ~6 or more million domains scattered across various TLDs and 2LDs, getting a few records from each domain (DNSKEY, MX, A + TLSA for each MX stopping early if same MX already seen at some other domain or is in an unsigned zone) and moves on to the next domain, visiting each delegated domain "once" (a few related queries in quick succession, in parallel with a few hundred similar domains). As mentioned originally, 3.5 billion queries, 1.4 million cache hits! Any advice on tuning for "surveys"? -- Viktor.