option to reset stats counters then reading them

[pettai]

• Program: dnsdist
• Issue type: Feature request

Short description

Make a possibility to reset (all) stats counters then reading them.

Usecase

reseting the stats counters upon reading them makes that stats gathering less error-prune. Many stats-gathering softwares doesn't cope with counters going backwards (after dnsdist is restarted).

Description

dnsdist stats just keeps on counting up, and as soon as dnsdist is restart, the statistics counters starts from zero again. This behavior confuses a lot of statistics gathering tools which get confused then dnsdist is restarted, making the graphs get huge spikes and faulty.

[Habbie]

added auth/rec labels because the feature was requested for all products in #11366