I’ve been using Chef and Capistrano to deploy a Nginx + Rails stack on a Digital Ocean for a while now, I use Nginx as a reverse proxy for unicorn upstreams. Recently I’ve upgraded one of my applications to the latest versions of Ruby (2.1.2) and Rails (4.1.2) in a sandbox staging environment that is virtualy identicle to the one in production in every way other than the Ruby and Rails version changes.
With my application deployed, and running using upstart, I’m getting a 502 Bad Gateway error message when I attempt to navigate to my application in the browser. Similarly, running a curl request on localhost:8080 returns curl: (52) Empty reply from server.
If I tail unicorn’s log files, however, it looks like all the requests are being picked up, but my workers are timing out:
Started GET “/” for 127.0.0.1 at 2014-06-12 14:38:17 -0400
Processing by ApplicationController#index as /
Rendered news/latest.html.haml (55.2ms)
Rendered upload_stores/featured.html.haml (141.9ms)
Rendered application/index.html.haml within layouts/application (211.0ms)
E, [2014-06-12T14:38:48.300405 #30669] ERROR – : worker=1 PID:329 timeout (31s > 30s), killing
E, [2014-06-12T14:38:48.328049 #30669] ERROR – : reaped #<Process::Status: pid 329 SIGKILL (signal 9)> worker=1
I, [2014-06-12T14:38:48.340087 #971] INFO – : worker=1 ready
So I tried doubling the timeout time in my unicorn configuration from 30 seconds to 1 minute but met similar results. If I load into my rails production console and fire off some queries, it seems to respond in sufficient time so I don’t think the holdup is on my database server…
Can anybody with experience using Unicorn suggest how I can go about debugging my timeouts further? Also note, I get these timeouts for every page, not just the root page.