suspicious test results with 'reuseport no'
Summary
This is suspicion, not a clear-cut bug.
BIND version used
- Affects v9.18: v9_18_11 Other versions were not tested.
Steps to reproduce
- use 16-thread machine
- I was testing in AWS VM type c5n.4xlarge for server and c5n.xlarge for client machine
- configure
reuseport no;
and "refuse everything" - use dnsperf 2.11 + JSON output MR:
-Q 100000 -S1 -O suppress=timeout,unexpected -c 256 -q 65535 -t 1 -l 60 -O verbose-interval-stats -O json -O latency-histogram
- query file with single line:
z123.test. SOA
- it should result in REFUSED because we don't have any such zone
- cycle through 10 dnsperf runs without restarting server
- hope that it reproduces erratic behavior; in my experiments it happens at least in in ~ 1/10 runs, sometimes more
What is the current bug behavior?
Sometimes the server has high latency. Dunno why. I was testing against echo server and it did not exhibit this behavior.
What is the expected correct behavior?
Even performance.
Relevant configuration files
Relevant logs and/or screenshots
Nothing suspicious.