Deploying Confluence on two EC2 hosts and sharing a database

[Debajit Adhikary]

I am trying to evaluate Confluence as a wiki tool for a large number of users. 

I set up Confluence on two EC2 hosts where they share one MySQL (RDS) database. The problem with this approach is that Confluence runs on one host, but the other host errors out saying “Database is in being used by another Confluence instance”.

Has anyone tried deploying Confluence on more than one host and sharing a database? Is there a way I can get Confluence to work this way? (My goal with using EC2 is to be able to horizontally scale our Confluence instance in the future)

[Nic Brough -Adaptavist- · Accepted solution]

Atlassian's documentation clearly states that this cannot work, and the reason your second installation errors is to prevent the damage you would do by running such a system.

For this to work, you need both Confluence systems to know exactly what the other one is doing, in real time, so that they do not stomp on each other's data.  That is a complicated thing to do, and most people do not need it, so historically, Confluence has not done it.  

In older versions of Confluence, there was a "cluster" solution that gave you some good scaling options, but that was not as good as Atlassian (or their customers) would have liked, so they've come up with a new system.

You need to look at Confluence Datacentre - it's not quite "one database, two Confluences", but it will do what you're trying to do.  Start at https://www.atlassian.com/enterprise/data-center