I have verified that my redis instance is running by using the redis-cli to issue a PING and received a PONG. I also used telnet from another server and received a +PONG.

Configuration:

/etc/logstash/logstash-redis.conf

input { stdin { } }
output {
stdout { codec => rubydebug }
redis { host => "<ip>" data_type => "list" key => "logstash" }
}

On redis, I have the standard configuration out of box from RPM.

I am following the configuration laid out in the Logstash Book by James Turnbull (granted he installs via tarball and me via RPM but the configuration should be the same).

Running $ logstash -agent -f /etc/logstash/logstash-redis.conf I get the standard warning about using milestone 2 output plugin 'redis'. I type hello world into the console. Logstash gives me the JSON output. Hostname is my current host I am sending from. No messages go to redis.