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Platform information:
- Hardware: armv7l, x86_64
- OS: debian, armbian, raspberryos
- Java Runtime Environment: zulu17.46+19, openjdk 17.0.9
- openHAB version: 4.1.1
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Issue of the topic:
- Multicast advertisement of openHAB instance leads to avahi errors flooding the logs (/var/log/syslog) with
avahi_normalize_name() failedmessages. - I started to investigate this issue when I noticed serious network performance degradation (made worse by running multiple openHAB servers on my network) and even non-responsive systems due to the logs filling up the entire partition with multiple avahi error messages per second. Removing avahi from the systems resolved the logging issues, however I still noticed strange mDNS behavior, even with only one openHAB instance running.
- My network has several vlans, but all openHAB servers run on the same network. Router / firewall that I use is OPNsense with unbound DNS, however this should not be relevant. I think I eliminated pretty much all other causes that could lead to this and I suspect others must have similar issues sooner or later as well. There are many other multicast (IoT) devices on the network that do not produce any of these issues and get IP addresses assigned just fine.
- Multicast advertisement of openHAB instance leads to avahi errors flooding the logs (/var/log/syslog) with
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Logs:
- Using the command
avahi-browse --resolve --allit can be seen that initially the multicast advertisement can be resolved, however additional openHAB advertisements are made that cannot all be resolved anymore to an IP address anymore and result in timeouts. With multiple openHAB instances running a flood of timeouts and errors can be observed.
- Using the command
+ wlp170s0 IPv6 openhab _openhab-server._tcp local
+ wlp170s0 IPv4 openhab _openhab-server._tcp local
+ wlp170s0 IPv4 openhab-ssl _openhab-server-ssl._tcp local
+ wlp170s0 IPv6 openhab-ssl _openhab-server-ssl._tcp local
= wlp170s0 IPv4 openhab-ssl _openhab-server-ssl._tcp local
hostname = [guesthouse-sst.local]
address = [192.168.1.48]
port = [8443]
txt = ["uri=/rest"]
= wlp170s0 IPv4 openhab _openhab-server._tcp local
hostname = [guesthouse-sst.local]
address = [192.168.1.48]
port = [8080]
txt = ["uri=/rest"]
+ wlp170s0 IPv4 openhab-ssl (2) _openhab-server-ssl._tcp local
= wlp170s0 IPv4 openhab-ssl (2) _openhab-server-ssl._tcp local
hostname = [guesthouse-sst.local]
address = [192.168.1.48]
port = [8443]
txt = ["uri=/rest"]
+ wlp170s0 IPv6 openhab-ssl (2) _openhab-server-ssl._tcp local
+ wlp170s0 IPv6 openhab (2) _openhab-server._tcp local
Failed to resolve service 'openhab' of type '_openhab-server._tcp' in domain 'local': Timeout reached
Failed to resolve service 'openhab-ssl' of type '_openhab-server-ssl._tcp' in domain 'local': Timeout reached
Failed to resolve service 'openhab-ssl (2)' of type '_openhab-server-ssl._tcp' in domain 'local': Timeout reached
Failed to resolve service 'openhab (2)' of type '_openhab-server._tcp' in domain 'local': Timeout reached
+ wlp170s0 IPv6 openhab (3) _openhab-server._tcp local
+ wlp170s0 IPv6 openhab (4) _openhab-server._tcp local
Failed to resolve service 'openhab (3)' of type '_openhab-server._tcp' in domain 'local': Timeout reached
+ wlp170s0 IPv6 openhab-ssl (3) _openhab-server-ssl._tcp local
+ wlp170s0 IPv6 openhab (5) _openhab-server._tcp local
+ wlp170s0 IPv4 openhab (5) _openhab-server._tcp local
= wlp170s0 IPv4 openhab (5) _openhab-server._tcp local
hostname = [guesthouse-sst.local]
address = [192.168.1.48]
port = [8080]
txt = ["uri=/rest"]
Failed to resolve service 'openhab (4)' of type '_openhab-server._tcp' in domain 'local': Timeout reached
+ wlp170s0 IPv6 openhab-ssl (4) _openhab-server-ssl._tcp local
Failed to resolve service 'openhab-ssl (3)' of type '_openhab-server-ssl._tcp' in domain 'local': Timeout reached
+ wlp170s0 IPv6 openhab (6) _openhab-server._tcp local
Failed to resolve service 'openhab (5)' of type '_openhab-server._tcp' in domain 'local': Timeout reached
+ wlp170s0 IPv6 openhab-ssl (5) _openhab-server-ssl._tcp local
Failed to resolve service 'openhab-ssl (4)' of type '_openhab-server-ssl._tcp' in domain 'local': Timeout reached
Failed to resolve service 'openhab (6)' of type '_openhab-server._tcp' in domain 'local': Timeout reached
+ wlp170s0 IPv6 openhab-ssl (6) _openhab-server-ssl._tcp local
Failed to resolve service 'openhab-ssl (5)' of type '_openhab-server-ssl._tcp' in domain 'local': Timeout reached
+ wlp170s0 IPv6 openhab (7) _openhab-server._tcp local
+ wlp170s0 IPv6 openhab-ssl (7) _openhab-server-ssl._tcp local
+ wlp170s0 IPv4 openhab-ssl (7) _openhab-server-ssl._tcp local
= wlp170s0 IPv4 openhab-ssl (7) _openhab-server-ssl._tcp local
hostname = [guesthouse-sst.local]
address = [192.168.1.48]
port = [8443]
txt = ["uri=/rest"]
Failed to resolve service 'openhab-ssl (6)' of type '_openhab-server-ssl._tcp' in domain 'local': Timeout reached
+ wlp170s0 IPv6 openhab (8) _openhab-server._tcp local
Failed to resolve service 'openhab (7)' of type '_openhab-server._tcp' in domain 'local': Timeout reached
+ wlp170s0 IPv6 openhab-ssl (8) _openhab-server-ssl._tcp local
Failed to resolve service 'openhab-ssl (7)' of type '_openhab-server-ssl._tcp' in domain 'local': Timeout reached
and this goes on and on…
I suspect that this issue started somewhere in December after an update of openHAB, possibly after the introduction of the mDNS addon discovery feature but I am not sure of this as I did not test older versions of openHAB. I did test and confirm this behavior on 5 different servers running different debian variants and java 17 variants (openjdk / zulu).
I managed to get my systems under control by turning off openHAB’s mDNS, this can be done by placing a file called org.openhab.mdns.cfg in openhab-userdata/etc with the following content:
enabled=false
Again, I find it hard to imagine that others would not run into similar issues, so I posted this issue (and workaround by simply turning multicast off).