Hi gurus we are using HAProxy 1.8.13 on Centos 7 with dynamically assigned backends (backend server IPs and ports assigned over stats socket by some python glue accessing namerd). This works fine.
We needed a method to make the dynamically assigned stuff stick over restarts and try to use the "load-server-state-from-file" directive. Sadly we are running into a bug: HAProxy does not restore the configured IP address present in the state file but falls back to the one in the config file at startup. Other information like uptime counter, state, port get restored. This only happens if the default server address in the config file is an IP. This does not happen with DNS names. If we switch out the default server addresses '127.0.0.1' in the config with 'localhost' it works as expected. We found this behavior with all tested versions (1.8.7, 1.8.13, 1.9-dev). The test config and example output are available in a Stack Exchange question I opened: https://serverfault.com/questions/930422/haproxy-use-saved-state-to-restore-backend-ips-possible You'll find two tiny patches attached, one for 1.8.13 and one for 1.9-dev. They work for our system and use case. Thanks for your great work Peter pe...@froehlich.cc --- 1.9-dev --- src/server.c 2018-09-12 12:02:48.000000000 +0000 +++ server.c 2018-09-12 12:02:41.000000000 +0000 @@ -4143,7 +4143,7 @@ goto srv_init_addr_next; for (srv = curproxy->srv; srv; srv = srv->next) - if (srv->hostname) + if (srv->hostname || srv->lastaddr) return_code |= srv_iterate_initaddr(srv); srv_init_addr_next: 1.8.13 --- server.c 2018-09-12 12:25:47.000000000 +0000 +++ src/server.c 2018-09-12 12:26:05.000000000 +0000 @@ -3957,7 +3957,7 @@ goto srv_init_addr_next; for (srv = curproxy->srv; srv; srv = srv->next) - if (srv->hostname) + if (srv->hostname || srv->lastaddr) return_code |= srv_iterate_initaddr(srv); srv_init_addr_next:
