是否可以在各个后端服务器上执行HTTP运行状况检查，并在活动后端服务器之间进行负载 balancer . 当我们在httpchk中提到主机名时，这适用于单后端服务器（选项httpchk GET / info HTTP / 1.1主机：\ abc.mysrv1.com）

但是我无法使用多个后端服务器成功配置它，因为我无法在httpchk命令上提供单独的主机名，并且在后端配置下获得http 400错误 -

backend svc.op
    balance roundrobin
    mode http
    http-send-name-header Host
    option httpchk GET  /info HTTP/1.1
    http-check send-state
    http-request set-uri /test/abcService
    server abc.mysrv1.com abc.mysrv1.com:80 check
    server abc.mysrv2.com  abc.mysrv2.com:80 check

[WARNING] 115/162226 (4788) : Server svc.op/abc.mysrv1.com is DOWN, reason: Layer7 wrong status, code: 400, info: "Bad Request: missing required Host header", check duration: 1ms. 1 active and 0 backup servers left. 0 sessions active, 0 requeued, 0 remaining in queue.
[WARNING] 115/162227 (4788) : Server svc.op/abc.mysrv2.com is DOWN, reason: Layer7 wrong status, code: 400, info: "Bad Request: missing required Host header", check duration: 0ms. 0 active and 0 backup servers left. 0 sessions active, 0 requeued, 0 remaining in queue.
[ALERT] 115/162227 (4788) : backend ' svc.op' has no server available!

$ ./haproxy -version HA-Proxy版本1.6.7 2016/07/13

更新：我没有追求这个，但有人建议关注 -

backend h_a01
    mode http
    option httpchk GET /health HTTP/1.1\r\nHost:\ a01\r\n
    http-check expect rstatus ^200
    http-request set-uri /hello/world
    http-request set-header Host a01
    server a01 a01 check

backend h_a02
    mode http
    option httpchk GET /health HTTP/1.1\r\nHost:\ a02\r\n
    http-check expect rstatus ^200
    http-request set-uri /hello/world
    http-request set-header Host a02
    server a02 a02 check

backend a
    mode http
    option forwardfor
    http-send-name-header Host
    http-request set-uri /hello/world
    server a1 a1 track h_a01/a01
    server a2 a2 track h_a02/a02
haproxy gateway