Chapter 8. Quota management architecture

With the quota management feature enabled, individual blob sizes are summed at the repository and namespace level. For example, if two tags in the same repository reference the same blob, the size of that blob is only counted once towards the repository total. Additionally, manifest list totals are counted toward the repository total.

The quota management feature works by calculating the size of existing repositories and namespace with a backfill worker, and then adding or subtracting from the total for every image that is pushed or garbage collected afterwords. Additionally, the subtraction from the total happens when the manifest is garbage collected.

The following database tables hold the quota repository size, quota namespace size, and quota registry size, in bytes, of a Red Hat Quay repository within an organization:

The organization size is calculated by the backfill worker to ensure that it is not duplicated. When an image push is initialized, the user’s organization storage is validated to check if it is beyond the configured quota limits. If an image push exceeds defined quota limitations, a soft or hard check occurs:

If storage consumption is within configured quota limits, the push is allowed to proceed.

Image manifest deletion follows a similar flow, whereby the links between associated image tags and the manifest are deleted. Additionally, after the image manifest is deleted, the repository size is recalculated and updated in the QuotaRepositorySize, QuotaNameSpaceSize, and QuotaRegistrySize tables.