We are are an IT Team for a government contractor and considering a hosted Jira Data Center for our Software Dev Teams we support. Each software dev team requires strict data separation, preferably at the database level. We've seen federated models, assuming these were using multiple instances of Jira Software with Crowd that appear to have met this need. However, given the discontinuance of Jira Software we would host Data Center and wondering what options are available to us?
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Server and Data Center are technically the same software now, and the only real difference is how you set them up and licence them.
So, yes, you can flip your servers to DC installations and keep them completely independent and separated.
You don't even need to do much migration or conversion work - if you are on a high enough version, you can apply DC licences to your servers (bear in mind you'll need to check any apps for compatibility and also get DC licences for the ones that are compatible) and you end up with a DC cluster with a single node.