# Problem catching nested exception **URL:** \ **Category:** Ruby\ **Created:** [October 27, 2008, 6:35pm UTC](https://www.ruby-forum.com/t/problem-catching-nested-exception/151903 "2008-10-27T18:35:51Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![TJTJTJ](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/b5ac83/32.png) [@TJTJTJ](https://www.ruby-forum.com/u/TJTJTJ)\ **Post date:** [October 27, 2008, 6:35pm UTC](https://www.ruby-forum.com/t/problem-catching-nested-exception/151903/1 "2008-10-27T18:35:51Z")
Hello, I’m new to ruby and just wrote a script that try to send many email, reading them from a database. For each domain, the script opens a TCP socket to the first available MX, and try to send as many email as it can. My problem is that my script does not always catch exception as I want, and I think my exception handling in nested loops is not correct. Here is a code extract, starting with a SMTP connection : ``` begin Timeout.timeout 1 do smtp = Net::SMTP.start mx, 25, $hostname end rescue Exception => e case e when Timeout::Error error = 'timeout connect' when Errno::ECONNREFUSED error = 'connection refused' when Errno::ECONNRESET error = 'connection reset' when Errno::EHOSTUNREACH error = 'host not reachable' else error = "unknown #{e.to_s}" end puts " KO #{error}, next MX" if $verbose next end domain.addr.each do |addr| puts " #{addr.email} (#{addr.id})" if $verbose begin Timeout.timeout 1 do smtp.send_message data, mailing.return_path, addr.email end rescue Exception => ee case ee when Net::SMTPServerBusy, Net::SMTPSyntaxError, ``` Net::SMTPFatalError, Net::SMTPUnknownError error = ee.to\_s.strip when Timeout::Error error = ‘001 timeout send’ when EOFError error = ‘002 eof’ when Errno::ECONNRESET error = ‘004 connection reset’ when TypeError error = ‘090 strange TypeError’ else error = “unknown #{ee.to\_s}” end puts " KO #{error}" if $verbose next end ``` puts " OK" if $verbose end smtp.finish break ``` “Most of the time” it works, but sometimes my script failed that way : ``` email@address (693792) KO 451 This server employs greylisting as a means of reducing ``` spam. Please resend e-mail shortly. /usr/lib/ruby/1.8/net/protocol.rb:133:in `sysread': Connection reset by peer (Errno::ECONNRESET) from /usr/lib/ruby/1.8/net/protocol.rb:133:in `rbuf\_fill’ from /usr/lib/ruby/1.8/timeout.rb:56:in `timeout' from /usr/lib/ruby/1.8/timeout.rb:76:in `timeout’ from /usr/lib/ruby/1.8/net/protocol.rb:132:in `rbuf_fill' from /usr/lib/ruby/1.8/net/protocol.rb:116:in `readuntil’ from /usr/lib/ruby/1.8/net/protocol.rb:126:in `readline' from /usr/lib/ruby/1.8/net/smtp.rb:664:in `recv\_response’ from /usr/lib/ruby/1.8/net/smtp.rb:651:in `getok' ... 8 levels... from /root/bin/mailing_3.rb:195:in `each’ from /root/bin/mailing\_3.rb:195 from /root/bin/mailing\_3.rb:193:in `each’ from /root/bin/mailing\_3.rb:193 I do not understand why Errno::ECONNRESET is not catch, because I use it in each rescue block, and I do not see why it would be thrown in another part of the script. I also do not understand why “sometimes” it work as I want and “sometimes” not. I removed some part of the script in this post because of its length, full script is available at : [http://pastie.org/301549](http://pastie.org/301549) Any comment will be greatly welcomed, not only for my exception problem, but I really need to understand that last one 😉 ---
**Author:** ![TJTJTJ](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/b5ac83/32.png) [@TJTJTJ](https://www.ruby-forum.com/u/TJTJTJ)\ **Post date:** [October 27, 2008, 10:30pm UTC](https://www.ruby-forum.com/t/problem-catching-nested-exception/151903/2 "2008-10-27T22:30:39Z")
It’s possible the exception is being raised where you do not expect it, e.g. in smtp.finish Try to find out exactly what line in mailing\_3.rb generates the exception. The fact that it is hidden under “… 8 levels…” is annoying here. I’m not sure if there’s a generic way to stop Ruby suppressing the intermediate levels of the exception report, but a simple solution is to wrap your code with: begin … rest of code rescue Exception =\> e STDERR.puts “#{e.message}\n#{e.backtrace.join(”\n")}" end ---
**Author:** ![TJTJTJ](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/b5ac83/32.png) [@TJTJTJ](https://www.ruby-forum.com/u/TJTJTJ)\ **Post date:** [October 28, 2008, 10:10am UTC](https://www.ruby-forum.com/t/problem-catching-nested-exception/151903/3 "2008-10-28T10:10:46Z")
On 2008-10-27, Brian C. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > It’s possible the exception is being raised where you do not expect it, > e.g. in smtp.finish You are right, exception was raised by smtp.finish, and I really did not expect it ! > Try to find out exactly what line in mailing\_3.rb generates the > exception. The fact that it is hidden under “… 8 levels…” is > annoying here. Yes, and I should rewrite those nested loops in a clean way. > I’m not sure if there’s a generic way to stop Ruby suppressing the > intermediate levels of the exception report, but a simple solution is to > wrap your code with: > > begin > … rest of code > rescue Exception =\> e > STDERR.puts “#{e.message}\n#{e.backtrace.join(”\n")}" > end Thank you for your time and all these informations. ---
**Author:** ![TJTJTJ](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/b5ac83/32.png) [@TJTJTJ](https://www.ruby-forum.com/u/TJTJTJ)\ **Post date:** [June 18, 2009, 8:54am UTC](https://www.ruby-forum.com/t/problem-catching-nested-exception/151903/4 "2009-06-18T08:54:24Z")
TJ wrote: > Hello, > > I’m new to ruby and just wrote a script that try to send many email, > reading them from a database. For each domain, the script opens a TCP > socket to the first available MX, and try to send as many email as it > can. please send a copy this script,thanks