Application Error “Request timeout” on Heroku

[guyaloni]

We managed to sync all assets with S3 using asset_sync gem.

When we run staging environment locally (rails s -e staging) the page is loaded with urls to s3.

When we try to do the same in staging environment, which run in Heroku server, after long waiting we get an Application Error screen. In server we see this log:

2015-07-24T10:00:26.387370+00:00 heroku[router]: at=error code=H12 desc="Request timeout" method=GET path="/es" host=www.xxxxx.com request_id=25ff85be-0aff-47f0-ae39-b44b68851f58 fwd="81.45.73.178" dyno=web.1 connect=2ms service=30004ms status=503 bytes=0
2015-07-24T10:00:26.924820+00:00 heroku[router]: at=info method=GET path="/favicon.ico" host=www.xxxxx.com request_id=5cd2c278-01c7-4e28-b258-2cc4fdc959c7 fwd="81.45.73.178" dyno=web.1 connect=12ms service=59ms status=200 bytes=285
2015-07-24T10:00:27.176669+00:00 app[web.1]: E, [2015-07-24T10:00:27.176445 #3] ERROR -- : worker=1 PID:10 timeout (31s > 30s), killing
2015-07-24T10:00:27.310096+00:00 app[web.1]: I, [2015-07-24T10:00:27.309736 #42]  INFO -- : worker=1 ready
2015-07-24T10:00:27.258744+00:00 app[web.1]: E, [2015-07-24T10:00:27.258582 #3] ERROR -- : reaped #<Process::Status: pid 10 SIGKILL (signal 9)> worker=1

Some idea what can it be?