[Pkg-utopia-maintainers] Bug#992989: avahi-daemon CPU usage increases over time

[Ryan Armstrong]

Package: avahi-daemon
Version: 0.8-5
Severity: normal

Dear Maintainer,

After upgrading to Debian Bullseye, I noticed that the Avahi CPU usage on my server machine was
quite high (eventually 100% of one core). After resetting Avahi, the CPU usage was normal then
eventually increased over time again until it was again rather high. The
increase appears to be (very roughly) 1 or 2% per hour on my rather humble Intel(R) Celeron(R) 
CPU 4205U @ 1.80GHz. 

Checking the journal, I only see the following sorts of lines:

Aug 25 16:21:30 zeta avahi-daemon[313333]: avahi_normalize_name() failed.
Aug 25 16:21:30 zeta avahi-daemon[313333]: avahi_key_new() failed.
Aug 25 16:21:30 zeta avahi-daemon[313333]: avahi_normalize_name() failed.
Aug 25 16:21:30 zeta avahi-daemon[313333]: avahi_key_new() failed.
Aug 25 16:21:31 zeta avahi-daemon[313333]: avahi_normalize_name() failed.
Aug 25 16:21:31 zeta avahi-daemon[313333]: avahi_key_new() failed.

Which was around the time I turned on another machine on my network.
However, the timing was not aligned with when Avahi CPU usage increased.
There is a possibility it is aligned with when I turn on my printer, but
I will need to investigate that further. I did not see anything else in
the log of note.

In the meantime, is there any means for me to gather additional
information to help diagnose this problem?

Thanks,
Ryan

-- System Information:
Debian Release: 11.0
  APT prefers stable-security
  APT policy: (500, 'stable-security'), (500, 'stable')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 5.10.0-8-amd64 (SMP w/2 CPU threads)
Locale: LANG=en_CA.UTF-8, LC_CTYPE=en_CA.UTF-8 (charmap=UTF-8), LANGUAGE=en_CA:en
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages avahi-daemon depends on:
ii  adduser              3.118
ii  bind9-host [host]    1:9.16.15-1
ii  dbus                 1.12.20-2
ii  init-system-helpers  1.60
ii  libavahi-common3     0.8-5
ii  libavahi-core7       0.8-5
ii  libc6                2.31-13
ii  libcap2              1:2.44-1
ii  libdaemon0           0.14-7.1
ii  libdbus-1-3          1.12.20-2
ii  libexpat1            2.2.10-2
ii  lsb-base             11.1.0

Versions of packages avahi-daemon recommends:
ii  libnss-mdns  0.14.1-2

Versions of packages avahi-daemon suggests:
pn  avahi-autoipd  <none>

-- no debconf information