Kibana 4 not running every morning

Every morning Nginx is telling me bad gateway. I go do a "service kibana status" and it's stopped. I start Kibana up again and all is good until the next morning. Nothing in the logs either.

Distributor ID: Ubuntu
Description: Ubuntu 14.04.1 LTS
Release: 14.04
Codename: trusty

Kibana 4.3.0

java version "1.8.0_31"
Java(TM) SE Runtime Environment (build 1.8.0_31-b13)
Java HotSpot(TM) 64-Bit Server VM (build 25.31-b07, mixed mode)