It has now happened tice that my Apache 2.4.41 (on Ubuntu 20.04) automatically performs a graceful restart around midnight, but the previously running website doesn't "come back". The relevant entries in /var/log/apache/error.log are

AH00171: Graceful restart requested, doing restart
[:error] [pid 443511] avahi_entry_group_add_service_strlst("XXXXX") failed: Not supported
[:error] [pid 443511] avahi_entry_group_add_service_strlst("XXXXX") failed: Not supported

where XXXXX is a valid fqdn under the .de top level domain (and I can only guess that the line occurs twice because it is once for http and once for https).

I don't know what really happens then: If I try a graceful restart by hand, it works without any problems. Searching for the "avahi_entry_group_add_service_strlst" message, I find only cases with other reasons, e.g. "Invalid host name" or "local name collision", but never "Not supported". Even less do I have an idea what could be the cause.


1 Answer 1


Inspired by the comment by Stephen Ostermiller, I did a

a2dismod dnssd

cause I have no idea why it was enabled on this box in the first place.

  • I figured that would be the solution if you weren't actually using the module. My guess is that the module is now enabled by default and Ubuntu. I've had to disable other modules after updates in the past. Apr 5, 2022 at 17:24

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