I, too, have observed this, occasionally, under OpenWrt. If you do figure this out, or get a solution/explanation off-line, we would really appreciate an update.
On Wed, Jan 31, 2018 at 1:12 PM, Zi Dvbelju <zidvbe...@gmail.com> wrote: > > > > > > > > > > > > > > > > *I’m experiencing an issue where all DNS resolutions sent to dnsmasq > timeout, but only after the dnsmasq service has been successfully running > for a period of time (anecdotally, after a few weeks of time). After a lot > of digging, I’ve discovered that dnsmasq’s UDP socket file will eventually > “disappear”. The issue can be resolved by restarting the dnsmasq service.I > haven’t been able to reproduce it yet, but it has happened numerous times > on servers which are running dozens of docker containers. From what I know, > nothing should be removing this socket file and I can’t find anything > relevant in the dnsmasq logs. Is anyone aware of any situations that can > cause socket files to disappear? EnvironmentUbuntu 16.04.3 LTS8 Cores, 16GB > of RAMDnsmasq 2.75-1ubuntu0.16.04.4BackgroundI’m using dnsmasq to forward > requests to Consul <https://www.consul.io/docs/guides/forwarding.html>, > which is used for service discovery. The Consul agent listens on port 8600 > and is configured to bind to all interfaces (the relevant interface here is > 172.17.0.1, which docker creates). Resolv.conf```# Dynamic resolv.conf(5) > file for glibc resolver(3) generated by resolvconf(8)nameserver > 127.0.0.1```Dnsmasq.conf ```server=/consul/172.17.0.1#8600 > <http://172.17.0.1/#8600>server=/10.in-addr.arpa/172.17.0.1#8600 > <http://172.17.0.1/#8600>bind-dynamic```Systemd config for > Docker```ExecStart=/usr/bin/dockerd --bip=172.17.0.1/24 > <http://172.17.0.1/24> --dns=172.17.0.1 -H fd://```While investigating the > servers in the broken state, I observed the following: - nslookup / dig DNS > resolutions are timing out- Docker logs show containers are also timing out > on DNS resolutions- Systemd reports that dnsmasq is still running, pid > still exists - DNS resolutions sent directly to the consul agent > (127.0.0.1:8600 <http://127.0.0.1:8600/>) succeed - DNS resolutions sent to > system[dnsmasq] (127.0.0.1:53 <http://127.0.0.1:53/>) time out- IPV6 UDP > (::1) resolutions sent to dnsmasq succeeded- Netstat shows that the IPV4 > UDP socket file for dnsmasq is missing- No relevant messages in kernel log > (specifically, no dnsmasq OOM kill events)- File descriptor usage for the > entire server was normal- File descriptor usage for the individual dnsmasq > process was normal- CPU, RAM, and storage all look goodThanks in advance > for any discussion at all - I've been really struggling with this one for a > while now.Zach* > > _______________________________________________ > Dnsmasq-discuss mailing list > Dnsmasq-discuss@lists.thekelleys.org.uk > http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss > >
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