default.vlc

vcl 4.0;

backend default {
    .host = "127.0.0.1";
    .port = "8081";
}

sub vcl_recv {
    # We use a header to track req.restarts value.
    set req.http.X-RESTARTS = req.restarts;

    # req.restart stays always 0 and thus
    # the condition is never true.
    if (req.restarts == 0) {
        unset req.http.X-FORCE-MISS;
    }

    # This condition is newer true as obj.hits
    # in vcl_hit stays always 0.
    if (req.http.X-FORCE-MISS == "1") {
        set req.hash_always_miss = true;
    }
}

sub vcl_hit {
    # We use a header to track obj.hits value.
    set req.http.X-OBJ-HITS = obj.hits;

    # obj.hits stays always 0 and thus
    # the condition is never true.
    if (obj.hits > 2) {
        set req.http.X-FORCE-MISS = "1";
        return (restart);
    }
}

sub vcl_deliver {
    # Here obj.hits increases like expected.
    if (obj.hits > 0) {
        set resp.http.X-Cache = "HIT";
        set resp.http.X-Cache-HITS = obj.hits;
    } else {
        set resp.http.X-Cache = "MISS";
    }
}