What causes EventMachine::ConnectionNotBound?

Question

I'm new to EventMachine, so I'm not sure what this means. I'm getting this exception:

EventMachine::ConnectionNotBound recieved ConnectionUnbound for an unknown signature: ef93a97d4d6441cb80d30fe2313d7de73

The program is fairly complicated, so I can't really explain everything that might have led up to it. All I need is a pointer towards what to look for. The error doesn't seem to be documented (looking at http://eventmachine.rubyforge.org/).

Answer 1

I have had this exception raised when some other unhandled exception was raised in the initialize method of a subclass of EventMachine::Connection. Check that the arity of your subclass initialize method is correct and that the initialize method is running without errors.

Answer 2

Usually, those errors occur in initialize or post_init. The first thing you should do is add rescue inside your callbacks to find out what actually is causing that error.

def initialize(*args)
  ...
  super
rescue Exception
  ...
end

def post_init
  ...
  super
rescue Exception
  ...
end

Answer 3

I fixed Exception bubbling for this case in EventMachine over a year ago. It's in the prerelease 1.0 gem (gem install eventmachine --pre) or better, use EventMachine from the repository.

Answer 4

I ran into a similar issue and while investigating came across https://github.com/igrigorik/em-http-request/issues/190#issuecomment-16995528

You basically need to wrap EM::HttpRequest.new with EM.schedule or EM.next_tick if you're making EM::HttpRequest.new in your code even though its under a EM.defer