Configuring redis:// url without port defaults the port to.... zero?

[dwbutler]

Hi,

We're using Faye::Redis running in Puma under JRuby. We had an issue for quite a while where Faye communication would just.... stop.

It turns out we were using a url like redis://host without specifying the default port (6379). After diving through the code, I found that em-hiredis defaults the port to nil here and then passes the nil port along to EM.connect.

Diving into Eventmachine, it appears that it calls to_i on the port here (at least in JRuby). This means that it is trying to connect to port 0, which doesn't make a lot of sense. Furthermore, there is no exception. It appears that em-hiredis simply blocks on IO until the Puma connection times out.

I'm not sure what the correct fix would be. My gut feeling is that em-hiredis should simply default the port to 6379. I also feel that Eventmachine shouldn't accept a nil port, because a missing port can't mean anything reasonable.

Thanks, let me know what you think!

[dwbutler]

Some more context in case you want to reproduce... We're using Amazon's Elasticache hosted Redis. When I run the following, it just hangs forever.

require 'socket'
socket=TCPSocket.open('yourserverhere.0001.use1.cache.amazonaws.com', 0)

This might be a configuration issue. Normally I would expect to see something like this:

require 'socket'
socket=TCPSocket.open('127.0.0.1', 0)
# => Errno::ECONNREFUSED: Connection refused - connect(2)