[dnsdist] backend drops metrics for TCP
cm at appliedprivacy.net
Mon Sep 11 20:34:58 UTC 2023
when playing around with things to reduce the drop rate I noticed
that TCP based backends always have 0 drops in showServers() output and
Is that always the case and that counter has no meaning for TCP based
backends or can this counter be non-zero for TCP backends as well?
dnsdist's CPU usage doubled after switching to TCP via tcpOnly=true
and the DNS timeout rate as measured by the application generating the
queries running on the same host as dnsdist actually increased after
switching dnsdist to use TCP instead of UDP. So switching to TCP
eliminated the drops problem when measured by dnsdist but it made things
worse for the application.
All of these values are also at 0:
are on the same level after switching to TCP for the specific backend.
Since sockets=NUM in newServer() is only for UDP and
suggests it uses only 10 TCP sockets. How can this be configured?
sockets was set to 32, so this implicit change when sitching from UDP to
TCP might also have an effect here.
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