These are just info messages. These mean that some local machine has not got a local domain name and has been assigned resolver.arpa but was then sent out for a DNS request.
resolver.arpa and service.arpa will be adeed to the local list in a future unbound update.
See this post thread for more info
https://community.ipfire.org/t/stop-service-arpa-requests-being-sent-to-upstream-dns/13447/12
If you want to stop those resolver.arpa and service.arpa FQDN’s being sent externally for DNS resolving now and not wait for the unbound update then there is a workaround in the above thread link.
These messages mean that the DNS server that was being used got no response from the root dns servers. This can happen periodically and after a short while it should work again.
Sometimes you have the message showing that the DNS server you use has received a SERVFAIL from the root dns server and sometimes you have the message “upstream server timeout” which means it got no response at all from the root zone.
If you get 1000’s of the SERVFAIL messages in a day in your log then the DNS server you are using has some sort of problem and you should look at the status of the various ones you have selected and maybe disable the one giving a problem.
If you get 10 or 50 or so of these messages per day then that is normal for networks that occasionally can have a problem. As long as you can still do your DNS resolving I would not worry about it.
I have a script that collects the data on how many of these I am getting and typically I get between 10 and 200 per week.
Occasionally I have 2000 in a week but I know that was when I was working on my red connection, to try and use a red vlan connection so I could connect to my fibre line without needing to use the modem from the ISP. That took some time to fix and so there were long periods without any internet connection so all DNS requests would have failed and show up as SERVFAIL messages.
Your log seems to be covering an 8 hour period so I would not consider that bad at all.