Reliable, High Performance TCP/HTTP Load Balancer. Quick News November 26th, 2017: HAProxy 1.8.0 released. One year after 1.7.0, we're pleased to announce release 1.8.0, which is by far the most feature-rich version ever produced.
Under the hood, plugins use one of several ACME protocol challenges to prove you control a domain. The options are http-01 (which uses port 80), tls-sni-01 (port 443) and dns-01 (requiring configuration of a DNS server on port 53, though that’s often not the same machine as your webserver).
Protecting Database Centric Applications. In the same way that some application require the ability to persist records to disk, for some applications the loss of access to the database means game over - more so than disconnection from the storage.