which is an error in our logging (or log aggregation) system - some
requests (apparently most of the slow ones) only pass through two tiers of varnish cache and XCache will look like
cp1067 miss (0), cp1054 frontend miss (0) and not cp1053 miss (0), amssq43 miss (0), amssq48 frontend miss (0)
(This might be a good time to ask, what do three varnish entries even
mean? AFAIK we only have to tiers, front and back.)
I believe its whether you hit eqiad or not. I believe non eqiad varnish hits eventually look things up in an eqiad varnish, so in essence there are three layers for some people.
--bawolff