Get "Connection refused" error when I tried "Setting Up an Advanced Logstash Pipeline"

Hey guys, I'm following the tutorial but encountered an error saying :
Connection refused {:class=>"Manticore::SocketException", :level=>:error} for "Setting Up an Advanced Logstash Pipeline".

I just followed the official tutorial (

And here is my config file:

input {
file {
path => "MYPATH/logstash-2.3.3/logstash-tutorial-dataset.config"
start_position => beginning
ignore_older => 0

filter {
grok {
match => { "message" => "%{COMBINEDAPACHELOG}"}
geoip {
source => "clientip"

output {
elasticsearch {}
stdout {}

If I delete "elasticsearch {}", the error disappears but still I can't observe any output. I tried it on two machines but with the same problem. And I'm developing on Ubuntu FYI.

Do somebody had the same problem before or know how to take care of it? Thanks you so much!!!!!

Is Elasticsearch running on the machine?