清漆 4 命中未命中 Header？

Question

有没有人更新过 header 为 Varnish 4 工作的命中率？

我找到的最后一个是版本 3。

https://www.varnish-cache.org/trac/wiki/VCLExampleHitMissHeader#Varnish3.0

寻找这些：

set beresp.http.X-Cacheable = "NO:Not Cacheable"; "NO:Got Session"; "NO:Cache-Control=private"; "YES";

可能还有其他有用的调试输出，说明为什么会错过请求。

Answer 1

是的，I have:

sub vcl_deliver {
    if (obj.hits > 0) { # Add debug header to see if it's a HIT/MISS and the number of hits, disable when not needed
        set resp.http.X-Cache = "HIT";
    } else {
        set resp.http.X-Cache = "MISS";
    }
    # Please note that obj.hits behaviour changed in 4.0, now it counts per objecthead, not per object
    # and obj.hits may not be reset in some cases where bans are in use. See bug 1492 for details.
    # So take hits with a grain of salt
    set resp.http.X-Cache-Hits = obj.hits;
}

将请求的 headers 的 varnish 3 版本直接翻译为 varnish 4:

sub vcl_backend_response {

    if (bereq.http.Cookie ~ "(UserID|_session)") {
        set beresp.http.X-Cacheable = "NO:Got Session";
        set beresp.uncacheable = true;
        return (deliver);

    } elsif (beresp.ttl <= 0s) {
        # Varnish determined the object was not cacheable
        set beresp.http.X-Cacheable = "NO:Not Cacheable";

    } elsif (beresp.http.set-cookie) {
        # You don't wish to cache content for logged in users
        set beresp.http.X-Cacheable = "NO:Set-Cookie";
        set beresp.uncacheable = true;
        return (deliver);

    } elsif (beresp.http.Cache-Control ~ "private") {
        # You are respecting the Cache-Control=private header from the backend
        set beresp.http.X-Cacheable = "NO:Cache-Control=private";
        set beresp.uncacheable = true;
        return (deliver);

    } else {
        # Varnish determined the object was cacheable
        set beresp.http.X-Cacheable = "YES";
    }

    # ....

    return(deliver);
}

有一些关于 upgrading to Varnish 4 的文档涵盖了这些内容：

vcl_fetch is now vcl_backend_response

hit_for_pass objects are created using beresp.uncacheable

req.* not available in vcl_backend_response

req.* used to be available in vcl_fetch, but after the split of functionality, you only have 'bereq.*' in vcl_backend_response.

清漆 4 命中未命中 Header？

Varnish 4 Hit Miss Header?

caching

varnish

varnish-vcl