We use HAProxy with Keepalived to loadbalance traffic and kubernetes master nodes.
Upon a restart of one backend server (one master) TCP connection is closed to fronted on all remaining nodes (other masters & worker nodes).
While I could expect it for a subset of nodes i.e. part of frontend TCP connections are closed because connectivity to one backend server is down (well technically it probably times out because reboot is ungraceful), I wouldn’t expect it for all nodes. It just looks that ALL frontend TCP connections are closed while just SINGLE backend server goes down. Is that correct behaviour or is there some misconfiguration ?
Config is as below:
defaults
log global
mode http
option httplog
option dontlognull
timeout connect 5000
timeout client 50000
timeout server 50000
frontend frontend-api
bind <backend_ip>:7443
bind <frontend_ip>:6443
bind 127.0.0.1:7443
mode tcp
option tcplog
timeout client 300000
default_backend backend-api
backend backend-api
mode tcp
option tcplog
option tcp-check
timeout server 300000
balance roundrobin
default-server inter 10s downinter 5s rise 2 fall 2 slowstart 60s maxconn 250 maxqueue 256 weight 100
server master1 <backend_api_ip_srv1>:6443 check
server master2 <backend_api_ip_srv2>:6443 check
server master3 <backend_api_ip_srv3>:6443 check
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