MLOps & Systems

model registry

/ MOD-ul REJ-iss-tree /

A model registry is an organized catalog of trained models — a single source of truth recording every version, where it came from, and whether it is approved for use. Think of a library's card catalog, but for models: instead of guessing which file on whose laptop is the 'real' production model, you look it up, see its version, its lineage, and its status. It is the bookshelf and the checkout desk for an organization's models.

For each model version, the registry stores not just the file but its story: which dataset and code produced it, how it scored on tests, who approved it, and whether it is currently a draft, in staging, in production, or retired. This turns a chaotic pile of files with names like 'model_final_v2_REALLY_final.bin' into a disciplined, auditable system. When something goes wrong in production, you can see exactly which version is live and roll back to a known-good earlier one in moments.

Why it matters: as soon as models are updated regularly and serve real users, you need to answer 'which version is running, and can we trust it?' — and a registry makes that answerable with confidence rather than detective work. The honest framing: a registry is bookkeeping, not intelligence. It does not make models better; it makes them manageable, accountable, and recoverable. Skipping it works fine until the day you desperately need to know what changed and have no record — which is exactly when its absence hurts most.

A new recommendation model, version 7, is promoted to production. Two days later complaints spike. The team opens the registry, sees v7 went live then, confirms v6 scored better on a key metric, and rolls back to v6 in one click — because the registry kept v6 ready and labeled.

Versioned and labeled — so 'what's live?' and 'roll it back' are quick, not frantic.

A registry catalogs models; it does not validate them. It will happily store a terrible model right next to a great one. The discipline of testing and approving a version before promoting it is a separate practice the registry merely records.

Also called
model catalogmodel versioning模型注册表模型仓库模型版本库