On Mon, Apr 21, 2014 at 7:43 PM, Daniel Sommermann <dcsommer@fb.com> wrote: > The "per server" approach only works if the server IP corresponds to a > single host. If the IP actually is served by multiple hosts, then multiple > healthcheck connections could be served by different instances (with > different maintenance times). I think in the general case, each HTTP/2 > connection needs this healthcheck. > > Yep, we healthcheck per server IP. > We do healthchecking per server IP for load balancing purposes as well, > but sometimes the the server IP is actually another proxy tier with many > hosts (we do L4 load balancing as well). > > If the server is another proxy itself (such as an L4 LB or a forward proxy, etc.) it does its own healthchecking of the backend servers. > So, I think for the reverse proxy healthchecking approach to work in > general, you need to do it per connection. > > At any rate, I don't think this approach can be made to work for forward > proxy. > > For forward proxies, we hold onto and then retry requests :(
Received on Tuesday, 22 April 2014 02:51:39 UTC