1.在client增加cookie

backend backend_www
    option forwardfor
    cookie SERVERID insert indirect nocache  #插入session信息
    option     redispatch  #當後端rs掛了，可立即切換，不會出現503錯誤
    option httpchk HEAD / HTTP/1.0
    balance roundrobin
    server www1 192.168.1.198:80 cookie www1check inter 2000 rise 30 fall 15
    server www2 192.168.1.52:80 cookie www2 checkinter 2000 rise 30 fall 15
 

2.balance source 根據原ip，經過hash計算後，指定後端固定的rs

backend backend_www
    option forwardfor
    option httpchk HEAD / HTTP/1.0
    balance source
    server www1 192.168.1.198:80 check inter2000 rise 30 fall 15
    server www2 192.168.1.52:80check inter 2000 rise 30 fall 15

原文：https://blog.51cto.com/chboy/1768133

haproxy中的session保持實現