probe tz1{
    .url="/demo/xxxx.index.html";    // 檢查后端健康頁面
    .timeout=0.3s;                   // 過期時間
    .window=8;                       // 檢查后端服務(wù)次數(shù)
    .threshod=3;                     // 檢查后端8次訪問，若成功3次則認(rèn)為服務(wù)是存活的
    .initial=3;                      // Varnish啟動，確保多少個probe正常
    .expected_response=200;          // 期望expected code，默認(rèn)是200
    .interval=6;                     // 定義probe多久檢查一次后端，默認(rèn)為5s
 }

 backend zachary{
    .host="127.0.0.1";
    .port="2222";
    .connect_timeout=1s;
    .first_byte_timeout=5s;
    .between_byte.timeout=2s;
    .max_connections=1000;
    .probe=tz1;
 }

 backend resource{
    .host="127.0.0.1";
    .port="8099";
    .connect_timeout=2s;             // 定義等待連接后端的時間
    .first_byte_timeout=5s;          // 定義等待從backend傳輸過來的第一個字節(jié)的時間
    .between_byte.timeout=2s;        // 定義兩個字節(jié)的間隔時間
 }

 director zachary random{            // 隨機(jī)
    .retries=5;                      // 查找可用后端次數(shù)
    {
        .backend=zachary;            // 引用已存在的backend
        .weight=6;
    }
    {
        .backend=resource;           // 引用已存在的backend
        .weight=2;                   // 類似Nginx權(quán)重
    }
    {
        .backend={                   // 定義新的backend

        }
        .weight=2;
    }
 }

 director zachary round-robin{       // 輪詢
    {
        .backend=zachary;            // 引用已存在的backend

    }
    {
        .backend=resource;           // 引用已存在的backend

    }
    {
        .backend={                   // 定義新的backend
        }

    }
 }

 #權(quán)限訪問控制列表
 acl purgeallow {
    "127.0.0.1";
    !"192.168.0.102"
 }

 sub vcl_recv{

    if(!req.backend.healthy){
        set req.grace=30m;           // Varnish緩存時間+50分鐘返回給客戶端
    }else{
        set req.grace=5s;
    }

    if (req.url ~ "\.(css|js|html|htm|bmp|png|gif|jpg|jpeg|ico|gz|tgz|bz2|t
        bz|zip|rar|mp3|mp4|ogg|swf|flv)($|\?)") {
        unset req.http.cookie;
        return (hash);
    }
    if(req.request== "PURGE"){
        (!client.ip ~ purgeallow){
            error 405 "not allowed";
        }
        return(lookup);
    }

    if (req.restarts == 0) {
        if (req.http.x-forwarded-for) {
            set req.http.X-Forwarded-For = req.http.X-Forwarded-For + ", " +client.ip;
        } else {
            set req.http.X-Forwarded-For = client.ip;
        }
    }
if (req.http.Cache-Control ~ "(?i)no-cache") {
       if (!(req.http.Via || req.http.User-Agent ~ "(?i)bot" || req.http.X-Purge)) {
           return (purge);
       }
    }
if(req.http.host ~"^(www.)?zachary.cn$"){
        set req.backnd=zachary;
    }

    if(req.request== "GET" && req.url ~ "\.(jpg|png|gif|swf|flv|ico|jpeg)$"){
        unset req.http.cookie;
    }

    if(req.request== "GET" && req.url ~ "(?i)\.jsp($|\?)"){
        set req.backnd=resource;
        return pass(pass);
    }
 }

 sub vcl_fetch{

    set beresp.grace=30m;              // 后端服務(wù)器返回Varnish緩存時間+50分鐘
    if(req.request== "GET" req.url ~ "\.(jpg|png|gif|swf|flv|ico|jpeg)$"){
        set beresp.ttl=1d;
    }

    if(req.url ~ "^.*/zachary/demo/.*"){
        set beresp.ttl=1d;
        return(deliver);
    }

 }

 sub vcl_hit{
    std.log("url hit,your need to check it; it's url ="+req.url);
    if(req.request=='PURGE'){
        set obj.ttl=0s;                // 清除緩存
        error 200 "Purged.";
    }
    return(fetch);
 }

 sub vcl_miss{
    std.log("url miss,your need to check it; it's url ="+req.url);
    if(req.request=='PURGE'){
        error 200 "Purged.";
    }

    return(fetch);
 }

backend zachary{
    .host="127.0.0.1";   // 指明后端主機(jī)
    .port="2222";
    .connect_timeout=1s;
    .first_byte_timeout=5s;
    .between_byte.timeout=2s;
    .max_connections=1000;
    .probe=tz1;
 }

 backend resource{
    .host="192.168.0.1"; // 指明后端主機(jī)
    .port="8099";
    .connect_timeout=1s;
    .first_byte_timeout=5s;
    .between_byte.timeout=2s;

 }

注意

Varnish允許定義多個backend后端服務(wù)器。