4 ms·

Author here. We take a daily snapshot and then store incremental changes in multiple time intervals to optimize the storage usage and optimize the time to resto

• ignoramous 3y ago
  Hi Ben: Ignoring the full snapshot, does LiteFS Cloud periodically restore backups from its interim LTX blobs to check whatever it has accumulated works? If not, what inherently about LTX ensures that restores will always work? Thanks.
  • benbjohnson 3y ago
    Good question. LTX uses a rolling checksum of the entire database at every transaction. Actually, it includes two checksums: one for the state of the database before the transaction and one for after the transaction. It's incremental so it's fast to compute and it allows us to verify the integrity of the snapshot when we generate it and when we read it back. It also ensures that writes from LiteFS are contiguous and are coming from a known prior state. There's some details about it in our "Introducing LiteFS" blog post[1] from last year. We don't currently run a "PRAGMA integrity_check" in the cloud service right now for a few reasons. For one, it can be resource intensive for large databases and, two, it won't work once we support LTX encryption. We do have a continuous test runner that writes to LiteFS Cloud, stops, fetches a snapshot, and performs integrity checks, and repeats. [1]: https://fly.io/blog/introducing-litefs/#split-brain-detection https://fly.io/blog/introducing-litefs/#split-brain-detectio...