Repeated error messages being output when broker goes down

[markiz]

I've got a consumer that uses Queue#pop method. After broker is restarted or closed, insane amounts of these error messages are output:

NoMethodError
undefined method `read_fully' for nil:NilClass
/Users/mark/.rvm/gems/ruby-1.9.3-p327@forum-corpus/bundler/gems/bunny-6fae2db09c0d/lib/bunny/transport.rb:109:in `read_next_frame'
/Users/mark/.rvm/gems/ruby-1.9.3-p327@forum-corpus/bundler/gems/bunny-6fae2db09c0d/lib/bunny/main_loop.rb:26:in `block in run_loop'
/Users/mark/.rvm/gems/ruby-1.9.3-p327@forum-corpus/bundler/gems/bunny-6fae2db09c0d/lib/bunny/main_loop.rb:22:in `loop'
/Users/mark/.rvm/gems/ruby-1.9.3-p327@forum-corpus/bundler/gems/bunny-6fae2db09c0d/lib/bunny/main_loop.rb:22:in `run_loop'

AMQ::Protocol::EmptyResponseError
Empty response received from the server.
/Users/mark/.rvm/gems/ruby-1.9.3-p327@forum-corpus/gems/amq-protocol-1.0.1/lib/amq/protocol/frame.rb:45:in `decode_header'
/Users/mark/.rvm/gems/ruby-1.9.3-p327@forum-corpus/bundler/gems/bunny-6fae2db09c0d/lib/bunny/transport.rb:110:in `read_next_frame'
/Users/mark/.rvm/gems/ruby-1.9.3-p327@forum-corpus/bundler/gems/bunny-6fae2db09c0d/lib/bunny/main_loop.rb:26:in `block in run_loop'
/Users/mark/.rvm/gems/ruby-1.9.3-p327@forum-corpus/bundler/gems/bunny-6fae2db09c0d/lib/bunny/main_loop.rb:22:in `loop'
/Users/mark/.rvm/gems/ruby-1.9.3-p327@forum-corpus/bundler/gems/bunny-6fae2db09c0d/lib/bunny/main_loop.rb:22:in `run_loop'

I assume it happens from here: https://github.com/ruby-amqp/bunny/blob/master/lib/bunny/main_loop.rb#L54

On our servers it kept outputting until we were out of disk space :(
This problem is actually two-fold:

1. There doesn't seem to be a way to detect broker going down
2. Tight loop that catches all exceptions and outputs A LOT. I think it's much better to simply fail when unknown error happens.

[markiz]

It should also be fairly easy to reproduce:

1. Launch irb console
2. Start consuming:

   
   
   1.9.3p327 :001 > b = Bunny.new
   
   1.9.3p327 :002 > b.start
   
   1.9.3p327 :003 > q = b.queue('a')
   
   1.9.3p327 :004 > loop { _, _, m = q.pop; puts(m.inspect) if m; sleep(0.5) }
   
   

3. Stop AMQP broker
4. Your console should be full of error messages

[michaelklishin]

Duplicate of #74