ELK + REDIS - Duplicating data

Talk to people,

I need a help ...

I have the following Logstash configuration files:

agent.conf

 input {
  log4j {
    type => "bdj"
    port => 25827
  }
}

filter{
    json{
        source => "message"
    }

}

output {
  stdout { 
    codec => rubydebug
  }
  redis {
    host => "127.0.0.1"
    data_type => "list"
    key => "logstash"
  }
}

This agent.conf receives the logs via tcp and forwards the redis.

central.conf

input {
  redis {
    host => "localhost"
    type => "redis-input"
    data_type => "list"
    key => "logstash"
  }
}

filter{
  json{
    source => "message"
  } 
}

output {
  stdout { }
  elasticsearch {
    hosts => "localhost"
    index => "logstash-%{+YYYY.MM.dd}"
  }

}

The problem is that the data is being duplicated, as if in a loop, or something like that.

I'm running logstash on a Debian, as a service.

root@logs:~# uname -a
Linux logs 3.2.0-4-amd64 #1 SMP Debian 3.2.78-1 x86_64 GNU/Linux

Any light?