这里是我的varnishconfiguration的一部分：
后端（＆S）＆导演（S）：
# cat backend-app02b.vcl backend app02b { .host = "192.168.52.153"; .port = "80"; .connect_timeout = 1s; # .first_byte_timeout = 5s; .between_bytes_timeout = 2s; .probe = probe1; } # cat backend-app02a.vcl backend app02a { .host = "192.168.52.152"; # .port = "http"; .port = "80"; .connect_timeout = 1s; # .first_byte_timeout = 5s; .between_bytes_timeout = 2s; .probe = probe1; } # cat backend-probe1.vcl // https://www.varnish-cache.org/trac/wiki/BackendPolling probe probe1 { .url = "/apc.php"; .timeout = 2s; .interval = 5s; .window = 5; .threshold = 3; } # cat director-app02.vcl director app02 round-robin { { .backend = app02b; } # { .backend = app02a; } } # cat vcl_recv/req.http.host.vcl if (req.http.host == "^XXX.XXX.XXX$" ) { set req.backend = app02; } # grep ^include default.vcl | grep -E 'backend|director' include "backend-probe1.vcl"; include "backend-app02a.vcl"; include "backend-app02b.vcl"; include "director-app02.vcl"; #
每当6app02a后端故意停机，所以6app02b应该踢了..但是，每当我运行GET（见下文）：
# GET -HHost:XXX.XXX.XXX http://6svprx01/ -ds 503 Service Unavailable #
我正在通过varnishlog ：
4 SessionOpen c 172.16.0.141 59555 172.16.0.141 4 ReqStart c 172.16.0.141 59555 1934193781 4 RxRequest c GET 4 RxURL c / 4 RxProtocol c HTTP/1.1 4 RxHeader c TE: deflate,gzip;q=0.3 4 RxHeader c Connection: TE, close 4 RxHeader c Host: XXX.XXX.XXX 4 RxHeader c User-Agent: lwp-request/5.827 libwww-perl/5.833 4 VCL_call c recv 4 VCL_acl c NO_MATCH e410 4 VCL_return c lookup 4 VCL_call c hash 4 Hash c / 4 Hash c XXX.XXX.XXX 4 VCL_return c hash 4 VCL_call c miss fetch 4 FetchError c no backend connection 4 VCL_call c error deliver 4 VCL_call c deliver deliver 4 TxProtocol c HTTP/1.1 4 TxStatus c 503 4 TxResponse c Service Unavailable 4 TxHeader c Server: Varnish 4 TxHeader c Content-Type: text/html; charset=utf-8 4 TxHeader c Content-Length: 686 4 TxHeader c Accept-Ranges: bytes 4 TxHeader c Date: Thu, 13 Jun 2013 19:41:03 GMT 4 TxHeader c X-Varnish: 1934193781 4 TxHeader c Age: 0 4 TxHeader c Via: 1.1 varnish 4 TxHeader c Connection: close 4 TxHeader c X-Served-By: 6svprx01.uftmasterad.org 4 TxHeader c X-Cache: MISS 4 Length c 686 4 ReqEnd c 1934193781 1371152463.051303864 1371152463.052740097 0.000216484 0.001306057 0.000130177 4 SessionClose c error 4 StatSess c 172.16.0.141 59555 0 1 1 0 0 0 295 686
我也看到：
0 Backend_health - app02b Still healthy 4--X-RH 5 3 5 0.010575 0.069739 HTTP/1.1 200 OK
只是为了validation后端是响应：
[root@6svprx01 varnish]# GET -HHost:XXX.XXX.XXX http://6app02b/ -ds 200 OK [root@6svprx01 varnish]#
那为什么varnish不能和后台进行沟通呢？ 特别是如果我能够通过GET ..
错误地定义了req.http.host 。 这就是造成这个问题的原因，完全匹配与正则expression式（即完全匹配内没有正则expression式）。
我不确定，因为导演的定义是错误的。
director app02 round-robin { { .backend = app02b; } # { .backend = app02a; } }
应该：
director app02 round-robin { { .backend = app02b; } { .backend = app02a; } }
您还应该使用varnishadm来检查后端运行状况
varnishadm debug.health