two confluence applications pointing at same DB

[Pat Condon]

This is probably a dumb question but here goes?  I am Confluence Admin and am in the process of transitioning from Windows stand alone Confluence application working with Oracle DB to Linux based Confluence application with Apache.

While in the process of transition, am I going break something if I have two Confluence applications pointing at the same DB?

Eventually, the goal will be DB for TEST-DEV and DB for PROD but that is not highest priority.

Thanks

[Nic Brough -Adaptavist- · Accepted solution]

There's two answers here, depending on what you mean by "database".  Sadly, database vendors have tried to use the same words to mean different things in this field and not gone along with the natural use of English either, and that messes explanations up.

Answer 1.

If you mean you want to point at the same "Database" in the sense that most people use the word ("I keep stuff in my database, if someone else is using my database, then it's all one big pile of tables in one place"), then

Yes, you will break your Confluence.

Confluence needs full read/write access to its database.  Confluence cannot tolerate anything changing the database without its knowledge.  So if Confluence A is happily running, when Confluence B tries to write to the database (and it will try to write, even if you've got no users active), it will break Confluence A.

So, no, do NOT even think about doing this.

Note - this reasoning doesn't apply to Confluence Clustered (now defunct) or Data Centre versions, but they do different things from what you're trying.

Answer 2.

If you mean the same database service, then you're fine.  By service, I mean "a piece of software that is running and providing many "databases"."  So when you log into your MySQL box for example, it shows you one process running MySQL-demon, and then you connect to that and type "show databases", it lists out "database 1: system stuff, database 2: confluence-live, database 3: confluence-test, and so-on".  As long as Confluence A and Confluence B have separate databases within that service, you're fine.

[Pat Condon]

Thank you for your help!

[Davin Studer]

Not a good idea. Especially when it comes to attachments. These are stored on the server, not the database. So, if you add an attachment on the test server and tried to access the page in the production server the attachment would be missing. I'm sure there are other things that could be bad, but that is the first, and in my opinion a big one, to come to mind.