Varnish VCL：我如何開啓req.backend_hint？

Question

我有以下VCL：

vcl 4.0; 

import std; 
import directors; 

backend one { 
    .host = "localhost"; 
    .port = "3333"; 
} 

backend two { 
    .host = "localhost"; 
    .port = "3333"; 
} 

sub vcl_init { 
    new random_director = directors.random(); 
    random_director.add_backend(two, 10); 
    random_director.add_backend(one, 8); 
} 

sub vcl_recv { 

    std.log("start vcl_recv"); 

    set req.backend_hint = random_director.backend(); 
    if (req.backend_hint == one) { 
     std.log("one"); 
    } else if (req.backend_hint == two) { 
     std.log("two"); 
    } else { 
     std.log("neither one"); 
    } 

    std.log("end vcl_recv"); 
} 

當我運行它時，輸出總是：

start vl_recv 
neither one 
end vcl_recv 

我如何正確檢查，看看哪個後端已選定？

感謝

Answer 1

在vcl_backend_fetch你應該能夠訪問bereq.backend.name

所以把你的代碼，你可能會碰到這樣的：

sub vcl_backend_fetch { 
    if (bereq.backend.name == "one") { 
     std.log("one"); 
    } else if (bereq.backend.name == "two") { 
     std.log("two"); 
    } else { 
     std.log("neither one"); 
    } 
}