Update: Moved the code to Github instead of inline in this blog post.
At work we run the Atlassian JIRA Data Center edition, which is basically a multi-node setup of the normal JIRA server setup. Since there was very little information online about an actual working nginx (plus) load balancing config for this setup, I decided to publish the one we ended up with and works well for us.
This one is built for nginx-plus, but if you leave out the health checks you can probably run in on the open source nginx version too.
Check the Github repository: https://github.com/karelbemelmans/jira-datacenter-nginx-load-balancer