analytics=# select count(req_path) as c, req_path from app_mantle where req_timestamp > '2015-02-27 00:20:00' and beresp_status like '5%%' group by req_path order by c DESC limit 5; c | req_path --------+-------------------------------- 940376 | /api/analytics/stats/track.gif 80 | /rss 63 | /api/profile/accountwithtoken 61 | /api/analytics/t/event.js 49 | / (5 rows)

"When you are not using pass, we have what is called "request collapsing". If there are multiples requests for the same content, and the first is a MISS, one request is sent to the origin and the remaining requests wait to reuse the response. The request form a line waiting for the response. However, if the TTL of the content is 0, then the remaining requests can't reuse the response and the next request in line is sent to the origin. This is causing a slow down."

- Fastly Support

if( req.url ~ "^/api/analytics/stats/track.gif" ) { return(pass) }

I never really finished this post about what pinch points in kinja the blue dress story surfaced, but its got a bunch of graphs so hitting publish...