dnsdist: Pool metrics don't match global metrics (DoH cache misses/hits)

[phonedph1]

• Program: dnsdist
• Issue type: Bug report

Short description

Global counters are accurate, but the pool counters are not. Seems like a variation of #12405 still in play.

Environment

• Operating system: Debian
• Software version: git
• Software source: semi-recently compiled

Steps to reproduce

1. Setup dnsdist for DoH, add a pool cache, and blast it with queries
2. Check global and pool counters for cache hits/misses

Expected behaviour

1. Similar type of numbers between global and pool

Actual behaviour

1. Pool counters are incrementing both, global counters fine

> dumpStats()
acl-drops                          	          0    latency1-10                        	          0
cache-hits                         	       1247    latency10-50                       	          0
cache-misses                       	          1    latency100-1000                    	          0

> getPool(""):getCache():printStats()
Entries: 1/100000
Hits: 1247
Misses: 1248

Other information

Similar issue as described in #12405, looks like global counters got updated, but maybe not pool counters.

Maybe this is just the way it has to work, which is also OK.