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Citadels

A Citadel is the customer-facing storage endpoint of a Storage Zone. The lionbackup client directs its uploads to it.

What a Citadel does​

A Citadel receives the encrypted data objects over HTTPS and:

  • checks the authentication (project-scoped access token),
  • checks quotas and limits (see Limits),
  • stores the objects in the attached, S3-compatible object storage.

Multiple Citadels per zone​

Several Citadels can be operated per Storage Zone. The client software selects an available endpoint. If a Citadel fails during the transfer, the client automatically switches to another available endpoint — without the backup run having to be restarted manually.

Anomaly detection​

You switch on the anomaly detection for your backups per project in the Portal. From the first backups it learns the project's rhythm — when, for how long, how much and how many files are backed up — and then reports:

  • unusual backup sizes, durations and file counts,
  • missing or extra backups.

It reports unencrypted or malformed archives (low data entropy or a damaged archive structure) from the first backup on. Anomalies appear in the portal under Messages.

Independently of that, security-relevant events of the Citadels are evaluated centrally for all projects, for example the use of tokens outside the intended project or an unusually large number of downloads in a short time. These security notices also appear in the portal and can optionally be delivered by email to registered recipients. Read more under Security.