Update benchmarks: resolver variables

benchmarks.md

@@ -47,7 +47,46 @@ See DNS-OARC 42, DNS Benchmarking 101: Essentials and Common Pitfalls [slides](h
     - Stop/restart also postproc job to pick up results from the restarted "test" jobs
   - Test results will be in the "postproc" job in the children pipeline - click on index.html, it will show you the most interesting jobs, or dive into subdirectories full of charts
 
+### Variables to consider
+Just a short list of the most important ones. Not a full list by a long short.
 
+- Client query patterns
+  - distribution of queries among clients (especially with stateful transports)
+  - theoretical cache hit ratio
+  - RD=1 queries
+  - DO=1 queries
+  - CD=1 queries
+- Client transport
+  - UDP with TCP fallback
+  - DoT
+  - DoH
+    - HTTP
+    - HTTPS
+  - TLS version
+  - TLS resumption
+  - TLS certificate/algorithm in use
+  - connection management - how clients and server manage idle connections
+- Resolver side
+  - forwarding
+    -  via DoT
+  - dnssec-validation
+  - cache size
+  - TTL limits
+  - availability of ipv4 and/or ipv6
+- RPZ/policy
+  - number of RPZ zones
+  - [RPZ zone config](https://bind9.readthedocs.io/en/latest/reference.html#namedconf-statement-response-policy)
+    - break-dnssec option
+    - min-update-interval option
+    - *-wait-recurse options
+  - content of RPZ zones
+  - update size
+  - update frequency
+- Auth side (i.e. how does the Internet behave)
+  - TTL of answers
+  - size of answers
+  - validity of answers
+  - weird answers - very long CNAME chains etc.
 
 ## Authoritative
 - :warning: Different queries have different processing cost - and it also depends on zone contents!