gst-print-notifications can provoke D-Bus message storm
See https://github.com/apple/cups/issues/5325#issuecomment-395887593
Because of a bug in CUPS 2.2.8, the IPP_GET_NOTIFICATIONS
requests from gsd-print-notifications
fail validation, causing CUPS to emit a ServerAudit
D-Bus signal which causes GSD to request notifications again. This results in a feedback loop and a storm of D-Bus traffic.
(This is further amplified by CUPS calling getpwnam
for each request, which, due to the failing validation, looks up the anonymous
user and hits the systemd dynamic user database via a new D-Bus connection. There are a quite a few processes involved in this.)
Even with the CUPS bug fixed, maybe gst-print-notifications
can be a bit more selective about which D-Bus signals it is interested in or when to re-request notifications? I think it's possible that GSD's requests will trigger signals from CUPS in the future.