Was DNS Server-Discovery ever considered as a way for an Open VSwitch to find it's controller?
We just implemented this for the host-sflow daemon and it seems to work well. The daemon is identical on every server, but you can change the settings for the whole data-center just by tweaking one file on the DNS server. For example, if /var/named/mycompany.com.zone is given: _sflow._udp 300 SRV 0 0 6343 collector1 _sflow._udp 300 SRV 0 0 6343 collector2 _sflow._udp 300 TXT ( "txtvers=1" "polling=20" ) then soon every daemon on every server will know to send sFlow to collector1.mycompany.com and collector2.mycompany.com with a collection interval of 20 seconds, checking back for configuration changes every 300 seconds. If a daemon can't reach the server for any reason then it just continues with the last known configuration. The SRV records can be assigned priorities and weights, so various failover/fallback designs are possible. host-sflow is an open-source project (http://host-sflow.sourceforge.net) which allows end-hosts to contribute their cpu/mem/disk stats using the same lightweight counter-push mechanism that sFlow-enabled switches (such as Open VSwitch) use to forward their interface counters every minute. That way the sFlow collector gets the full picture. So far it has been ported to Linux, Windows and Citrix XenServer 5.5. The code that makes the DNS SRV and TXT queries is in src/Linux/dnsSD.c. Regards, Neil _______________________________________________ discuss mailing list discuss@openvswitch.org http://openvswitch.org/mailman/listinfo/discuss_openvswitch.org
