cached objects don't expire in Varnish 4.1.1

Question

I have an issue with Varnish 4.1.1. I need expire static content based in TTL. The vcl_backend_response block have the following settings:

sub vcl_backend_response {
 if (beresp.http.Surrogate-Control ~ "ESI/1.0") {
  unset beresp.http.Surrogate-Control;
  set beresp.do_esi = true;
}
if (beresp.status == 301 || beresp.status == 302) {
  set beresp.http.Location = regsub(beresp.http.Location, ":[0-9]+", "");
}
if (beresp.status == 500 || beresp.status == 502 || beresp.status == 503 || beresp.status == 504) {
  return (abandon);
}
if (bereq.url ~ "^https?:\/\/(www\.)?sample\.com(\/.*)?$|^https?:\/\/((www\.)?(media|media1)\.)?sample\.com(\/.*)?$") { // This code filter my URL
if (bereq.url ~ "^[^?]*\.(css|js)(\?.*)?$") { // This code store css and js
  unset beresp.http.set-cookie;
  if (beresp.ttl <= 0s || beresp.http.Set-Cookie || beresp.http.Surrogate-control ~ "no-store" || (!beresp.http.Surrogate-Control && beresp.http.Cache-Control ~ "no-cache|no-store|private") || beresp.http.Vary == "*") {
   set beresp.ttl = 1m; 
   set beresp.uncacheable = true;
   return (deliver);
  }
}
if (bereq.url ~ "^[^?]*\.(jpeg|jpg|gif|png)(\?.*)?$") {// This code store images
   unset beresp.http.set-cookie;
   if (beresp.ttl <= 0s || beresp.http.Set-Cookie || beresp.http.Surrogate-control ~ "no-store" || (!beresp.http.Surrogate-Control && beresp.http.Cache-Control ~ "no-cache|no-store|private") || beresp.http.Vary == "*") {
    set beresp.ttl = 1m; 
    set beresp.uncacheable = true;
    return (deliver);
  }
}

The above code works fine but the objects don´t expire based in the TTL defined. The storage parameter in Varnishstat Agent doesn´t update the field. Nevertheless, the following code does works correctly (clear all cache):

sub vcl_backend_response {
   set beresp.ttl = 1m;
   return(deliver);
}

My question is: Is it normal this behavior in varnish?

Regards.

Answer 1

The code "above":

• works only for CSS and JS which have Expires in the past, have Cookie or Cache-Control; or in other words, which tell Varnish not to cache them
• overrides TTL to 1 min
• marks them as hit-for-pass and not cacheable for 1 minute
• unnecessarily complex

This will work as you want it to work:

sub vcl_backend_response {
    if (bereq.url ~ "^[^?]*\.(css|js)(\?.*)?$") { 
        unset beresp.http.set-cookie;
        set beresp.ttl = 1m; 
    }
    if (bereq.url ~ "^[^?]*\.(jpeg|jpg|gif|png)(\?.*)?$") {images
        unset beresp.http.set-cookie;
        set beresp.ttl = 1m; 
    }
}

Basic advice - don't try to copy paste things from Internet without trying to understand how things work. Your VCL clearly indicates heavy copy paste work without thinking little on what's going on.