An excellent Guide for Ubuntu 14.04 is at https://www.digitalocean.com/community/tutorials/how-to-install-elasticsearch-logstash-and-kibana-elk-stack-on-ubuntu-14-04
PacketBeat - https://z0z0.me/monitor-your-servers-with-elasticsearch-2-x-and-beats-and-display-it-in-kibana/
GeoIP Support - https://www.digitalocean.com/community/tutorials/how-to-map-user-location-with-geoip-and-elk-elasticsearch-logstash-and-kibana
Make sure the server time is correct for all servers as in use NTP.
This actually gave me a problem where logstash => ElasticSearch did not work
Sample code for my Confluence Server
Sample code for my Alfresco Server