In a 2-tier haproxy setup (tier1 instances/VMs do domain steering (and some SSL termination) across many 10s of backends to tier2 path-steering instances),.
I'd like to scale either/both tiers horizontally without compounding <#tier1 instances> * <#backends> * <#tier2 instances> healthcheck overhead. The 'observe' keyword intrigues as a possible passive/implicit healthcheck mode? http://cbonte.github.io/haproxy-dconv/configuration-1.5.html#observe My read of the docs (and googling for more insight or sample configs), with a code perusal imminent) leaves me not-yet-enlightened as to "observe layer4"'s fitness to my purpose. Am I barking up a non-existent tree? If it would work, how would haproxy know to bring a backend back into rotation ? ... backend BACKEND_025 balance roundrobin server dlb01 dlb01:10025 check port 60000 inter 5s rise 2 fall 1 [ ... ] server dlb07 dlb07:10025 check port 60000 inter 5s rise 2 fall 1 ... would become ... backend BACKEND_025 balance roundrobin server dlb01 dlb01:10025 check observe layer4 inter 5s rise 2 fall 1 [ ... ] server dlb22 dlb22:10025 check observe layer4 inter 5s rise 2 fall 1 ? Thanks, ...jfree
