https://bugzilla.wikimedia.org/show_bug.cgi?id=44097
--- Comment #1 from Roan Kattouw <[email protected]> --- There are two separate issues here: * "due to the way bits works" ** I don't know what mutante is referring to there * "geolocation" ** we use CNAMEs to do geolocation, and wikidata.org can't be a CNAME, so second-level domains cannot be geographically load-balanced As an illustration, en.wikipedia.org resolves in a chain, as follows: $ host en.wikipedia.org en.wikipedia.org is an alias for wikipedia-lb.wikimedia.org. wikipedia-lb.wikimedia.org is an alias for wikipedia-lb.eqiad.wikimedia.org. wikipedia-lb.eqiad.wikimedia.org has address 208.80.154.225 wikipedia-lb.eqiad.wikimedia.org has IPv6 address 2620:0:861:ed1a::1 Note that wikipedia-lb.wikimedia.org is a CNAME pointing to wikipedia-lb.eqiad.wikimedia.org (eqiad is the Virginia datacenter). The target of this CNAME will vary depending on where you are located. Running the same command from Europe, the same CNAME points to esams (Amsterdam) instead: $ host en.wikipedia.org en.wikipedia.org is an alias for wikipedia-lb.wikimedia.org. wikipedia-lb.wikimedia.org is an alias for wikipedia-lb.esams.wikimedia.org. wikipedia-lb.esams.wikimedia.org has address 91.198.174.225 wikipedia-lb.esams.wikimedia.org has IPv6 address 2620:0:862:ed1a::1 This is how we do geographic load balancing: the CNAMEs wiki$project-lb.wikimedia.org point to wiki$project-lb.$location.wikimedia.org , where $location depends on who's asking and where we believe they are. But to make this work, the domain names used by humans (like en.wikipedia.org) have to point to one of these -lb.wikimedia.org CNAMEs, which means they themselves have to be CNAMEs. And second-level domains like wikidata.org cannot be CNAMEs, so this strategy falls apart: $ host www.wikidata.org www.wikidata.org is an alias for wikidata-lb.wikimedia.org. wikidata-lb.wikimedia.org is an alias for wikidata-lb.eqiad.wikimedia.org. wikidata-lb.eqiad.wikimedia.org has address 208.80.154.242 wikidata-lb.eqiad.wikimedia.org has IPv6 address 2620:0:861:ed1a::12 $ host wikidata.org wikidata.org has address 208.80.152.218 I'm not sure whether it's possible to do geographic load balancing for second-level domains with some other approach that doesn't use CNAMEs, but our current approach won't work in this case. -- You are receiving this mail because: You are the assignee for the bug. You are watching all bug changes. _______________________________________________ Wikibugs-l mailing list [email protected] https://lists.wikimedia.org/mailman/listinfo/wikibugs-l
