Welcome to the community!
Congratulations on embarking on this journey! You’re quite a bit behind, so you’ve got several milestones to achieve:
- upgrade from 5.3 to 5.6.7
- upgrade from 5.6.7 to 6.7.7
- migrate from MySQL to the supported database of your choice ( link to FLOSS migrator at the end of the first post in this thread)
- upgrade from 6.7.7 to 7.9.1
As a reminder, here’s the upgrade procedure. You’ll find all the historical versions on the Downloads page. There are a couple things to take note of before you start tho:
- You say you’re “using enterprise level”. It’s not clear to me whether you mean you’re using paid, enterprise features or just that you have a large, high-volume instance. The licensing model has changed since 5.3. If you’re using commercial features, you need to contact your sales rep or whoever it is you’ve dealt with previously at SonarSource on the business end to sort out your license key.
- IIRC, some of the migrations you’re facing can be lengthy. Don’t start this on a Monday morning. If I were you I’d run through the whole thing first on a test instance.
Regarding hardware, we don’t have hard-and-fast rules on that, but the docs should help.