Rails Mailer “Net::OpenTimeout: execution expired” Exception on production server only

Question

I am using Ruby MRI 2.0.0 and Rails 3.2.12 on a Ubuntu 12.04 TLS VPS and attempting to setup email notifications in my app. It was working fine a few days ago, but n

Answer 1

I probably had the same issue, my production application didn't send mails although everything in development was working fine. I also got the "Net::OpenTimeout" error.

My problem was that i was using a Google server in production, and it blocks ports 25, 465 and 587 on outbound connections.

Since I was using Mandrill for sending mails, I was able to switch the connecting port from 587 to 2525 and everything is okay now.

Answer 2

The issue was due to an IPv6 misconfiguration on the production server and has now been fixed.

Answer 3

I added these to /etc/gai.conf in CentOS7 and it worked.

label       ::1/128        0
label       ::/0           1
label       2002::/16      2
label       ::/96          3
label       ::ffff:0:0/96  4
precedence  ::1/128        50
precedence  ::/0           40
precedence  2002::/16      30
precedence  ::/96          20
precedence  ::ffff:0:0/96  100

http://blog.asiantuntijakaveri.fi/2014/12/prefer-ipv4-over-ipv6-on-centos-6.html:title

Answer 4

Try this, if all above fails

I got it solved by adding this in application.rb under config

 require 'net/http'

 require 'openssl'

 require 'resolv-replace'

Answer 5

Here is also a temporary fix that may come in handy while waiting for your hosting provider to fix the issue:

Add the following lines to /etc/sysctl.conf:

#disable ipv6
net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1
net.ipv6.conf.lo.disable_ipv6 = 1

Now reload the sysctl service using the following command:

sudo sysctl -p

Now the apps are able to send emails again.

You can always know if IPv6 is enabled calling

cat /proc/sys/net/ipv6/conf/all/disable_ipv6

from terminal. Two possible answers: 0 => IPv6 is enabled; 1 => IPv6 disabled.

From: https://serverfault.com/questions/512744/timeout-error-in-all-my-apps-for-every-call-to-smtp-servers

Answer 6

You can configure Ubuntu to prefer IPv4 over IPv6. This way you will be able to send emails and access IPv6-only sites. Edit /etc/gai.conf and uncomment the following line:

precedence ::ffff:0:0/96 100