I inherited a legacy app running Thinking Sphinx v3. I've been working on a large update for it, upgrading rails, etc.
My updated app now has a different Thinking Sphinx index, but it shares the same schema. It also uses delta indexing with Delayed Job.
I have a beta environment fully up and running but I now want to point the beta app to the production database so my colleagues can test the update safe in the knowledge that if anything goes awry they can always fallback to the live app.
Is it possible for these two environments to co-exist? How should I be configuring my app or the database server?
It's generally possible to have two apps pointing to the same database, yes. Of course, there may be behaviours in one that impact the other, so you'd want to consider that complication!
With regards to Thinking Sphinx: each app's daemon and index data will be separate from the other, so that won't be a problem either. If you're running both apps on the same machine, though, you'll want to make sure the daemons are using different ports through the mysql41 setting.