NGINX: upstream timed out (110: Connection timed out) while reading response header from upstream

Question

I have Puma running as the upstream app server and Riak as my background db cluster. When I send a request that map-reduces a chunk of data for about 25K users and returns i

Answer 1

From our side it was using spdy with proxy cache. When the cache expires we get this error till the cache has been updated.