backend pic_yourdomain_1 {
    .host = "1.2.3.4";
    .port = "80";
    .probe = {
        .interval = 20s;
        .timeout = 20s;
        .window = 5;
        .threshold = 3;
        .request = 
            "HEAD / HTTP/1.1"
            "Host:host.yourdomain.com"
            "Connection:close";
    }   
}
backend pic_yourdomain_2 {
    .host = "1.2.3.5";
    .port = "80";
    .probe = {
        .interval = 20s;
        .timeout = 20s;
        .window = 5;
        .threshold = 3;
        .request = 
            "HEAD / HTTP/1.1"
            "Host:host.yourdomain.com"
            "Connection:close";
    }   
}

director pic_yourdomain random {
    {
        .backend = pic_yourdomain_1;
        .weight = 5 ;
    }
    {
        .backend = pic_yourdomain_2;
        .weight = 5 ;
    }
}

acl purge {
		"localhost";
		"127.0.0.1";
		"192.168.1.0"/24;
		"219.239.89.0"/25;
		"218.241.222.114";	
}

sub vcl_recv {
	if (req.http.Accept-Encoding) {
		if (req.url ~ "(?i)\.(ico|bmp|jpg|png|gif|jpeg|flv|swf)" ) {
			remove req.http.Accept-Encoding;
			remove req.http.Cookie;
		} else if (req.http.Accept-Encoding ~ "(?i)gzip") {
			set req.http.Accept-Encoding = "gzip";
		} else if (req.http.Accept-Encoding ~ "(?i)deflate") {
			set req.http.Accept-Encoding = "deflate";
		} else {
			remove req.http.Accept-Encoding;
		}
	}
	
	if (req.url ~ "(?i)\.(jpg|jpeg|png|gif|bmp|css|js|swf|flv|mp3|wmv|wav|avi)($|\?)" ) {
	if (req.http.referer && !req.http.referer ~ "(yourdomainimages|yourdomain|120ping|fx120|120\.net|iiyi\.com|120sc\.net|aids120|byby120|ruxian120|fkyz120|zhe    ngxing999|google|baidu|soso|yahoo|youdao|bing|sohu)" ) {
  	  	error 404 "not found"; 
  	  }  
	}

  	if (req.http.host ~ "yourdomain.com") {
		set req.backend = pic_yourdomain ;
	} else if(req.http.host ~ "img.yourdomain.com") {
		set req.backend = pic_yourdomain;
  	} else {
    	error 405 "bad hostname";
  	}
  
  	#set client.identity = client.ip ;

	set req.http.X-Forwarded-For = client.ip ;
	
	if (req.backend.healthy) {
    	set req.grace = 10s;
  	} else {
    	set req.grace = 3h;
 	 }

    if (req.request == "PURGE") {
         if (!client.ip ~ purge) {
            error 405 "Not Allowed";
          }
          return (lookup); 
    }

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

    if (req.request != "GET" &&
      req.request != "HEAD" &&
      req.request != "PUT" &&
      req.request != "POST" &&
      req.request != "TRACE" &&
      req.request != "OPTIONS" &&
      req.request != "DELETE") {
        return (pipe);
    }

    if (req.request != "GET" && req.request != "HEAD") {
        return (pass);
    }

    if (req.http.Authorization) {
        return (pass);
    }

    #if (req.request == "GET" && req.url ~ "(?i)\.(jsp|php|asp|aspx)($|\?)") {
    #    return (pass);
    #}

    return (lookup);
}

sub vcl_pipe {
    return (pipe);
}

sub vcl_pass {
    return (pass);
}

sub vcl_hash {
    hash_data(req.url);
    if (req.http.host) {
        hash_data(req.http.host);
    }
    return (hash);
}

sub vcl_hit {
	if (req.request == "PURGE") {
		set obj.ttl = 0s;
    	error 200 "Purged";
	}

	if ( req.http.Pragma ~ "no-cache" && client.ip ~ purge) {
		set obj.ttl=0s;
		return (pass);
	}

  return (deliver);
}
 
sub vcl_miss {
	if ( req.request == "PURGE" ) {
		error 404 "not found";
	}

  return (fetch);
}

sub vcl_fetch {

	if (beresp.http.Set-Cookie) {
		return (hit_for_pass);
	}

	if (beresp.ttl <= 0s ) {
		return (hit_for_pass);
	}

	if (!beresp.http.Last-Modified) {
		return (hit_for_pass);
	}
	
	if (beresp.http.Pragma ~ "(?i)no-cache" || beresp.http.Cache-Control ~ "(?i)(no-cache|private)") {
		
		return (hit_for_pass);
	}

	set beresp.grace = 4h;
	unset beresp.http.vary;
    unset beresp.http.Etag;

   return (deliver);
}

 sub vcl_deliver {
     if (obj.hits > 0) {
       		set resp.http.Powered-By-Cache = "HIT 5433 " + obj.hits;
     } else {
       		set resp.http.Powered-By-Cache = "MISS 5433";
     }
	unset resp.http.X-Varnish;
	unset resp.http.Via;
	return (deliver);
 }
 
 sub vcl_error {
	
     set obj.http.Content-Type = "text/html; charset=utf-8";
     set obj.http.Retry-After = "5";
     synthetic {"
 <!DOCTYPE html>
 <html>
   <head>
     <title>"} + obj.status + " " + obj.response + {"</title>
   </head>
   <body>
     <h1>Error "} + obj.status + " " + obj.response + {"</h1>
     <h3>Guru Meditation:</h3>
     <p>XID: "} + req.xid + {"</p>
     <hr>
     <p>cache server 5433</p>
   </body>
 </html>
 "};
     return (deliver);
 }
 
 sub vcl_init {
 	return (ok);
 }
 
 sub vcl_fini {
 	return (ok);
 }