Beresp.backend.name not set

Network Services
1

The documentation for beresp.backend.name tells me that this variable is preferred if a director is in use. But I always get (null) on it, when logging it from vcl_log. If I query rep.backend, then I get the director’s name, which makes sense. Is this WAI? Is there another field I could log to get the actual backend (either name or IP)? Or maybe I’m holding it wrong altogether, as I just put a backend=%{beresp.backend.name}V into my log line in vcl_log.

I’m a bit surprised that no-one seems to log the backend that actually served their request. Maybe because people generally have access to the backend logs and check for the request there?

2

Reading Access to beresp.http headers in Logging I wonder if what’s happening is that the cached object doesn’t persist beresp.backend.name? So maybe I need to copy it over into a header and retrieve it from there? That’d at least explain the (null), even though beresp.backend.name is documented to be available in vcl_log.

And it’s not like we’re using complicated VCL logic that’d by itself tamper with what object we’re seeing in services/archive.yaml · master · Debian System Administrators / mirror / cdn-fastly · GitLab.