SSTables with UUID ID were introduced to Scylla a long time ago, but we disable them in SM tests with the following scylla.yaml configuration:

uuid_sstable_identifiers_enabled: false

We do it because we wanted to test the backup deduplication mechanism and it required some SSTables with integer based IDs.

It would be nice if we could just test the UUID IDs, as this is the default and most common case, but unfortunately for us, many users can still have both integer based and UUID SSTables in the same cluster (only new SSTables are written with UUIDs while some old ones could never been re-written and still have integer based ID).

For now I see 3 ways to tackle this problem:

• introduce another test env param (e.g. UUIDSSTABLES) which could control uuid_sstable_identifiers_enabled.
  This is quick and easy, but it wouldn't allow for testing mixed ID scenarios.
• always enable UUID SSTables, but manually rename some UUID SSTables to integer based ones after taking the snapshot and before deduplicating the files in tests which needs to verify integer based SSTable deduplication.
  This is probably the most correct approach, but it would require the most effort as well.
• test deduplication on some pre-created snapshot dirs with mixed SSTable IDs.
  There is a question of how easy would it be to integrate pre-created SSTables with our test scenarios which usually create a real backup from a real cluster.