Adaptation

The corpus has its canonical ring and its frames. Now it must adapt to its environment — how much to hold, where to hold it, what to do when the ring fills. But first, two concepts must be distinguished.

Depth and range

Depth is the observation chain from Lesson 106. S, M, H, D, W. Multiple timescales running simultaneously. S captures every frame. M observes S and writes its own report every minute. H observes M and writes its own report every hour. Each cog at its own resolution, each writing its own account. Depth is seeing the same reality at different timescales at the same time — the three rings of the clock from Lesson 101.

Range is how far back you can see on a single timeline. A ring that holds 1,000 frames sees back 1,000 frames. A ring that holds 10,000 frames sees back 10,000 frames. Same resolution. Same timeline. More of it.

Depth operates across timescales. Range operates within a single timescale. The observation chain manages depth. This lesson manages range.

Environment

Not every corpus faces the same world. One corpus captures telemetry from a satellite — frames arrive in bursts, storage is precious, and nothing can be lost. Another corpus captures temperature readings in a greenhouse — frames arrive steadily, storage is cheap, and last week's readings have diminishing value. A third corpus captures financial transactions — regulators demand permanent retention, and access patterns shift between hot queries and cold audits.

The canonical ring from Lesson 203 holds the frames. But how the ring behaves — what it does when it fills, where frames go next, how storage resources are matched to access patterns — that is adaptation. The corpus shapes itself to its environment by managing range.

Three modalities

Each temporal ring has three behaviors available to it:

Archive. The ring produces a series of linear files. When a file fills, it is closed and a new one opens. Capture continues into the new file. The chain grows. Nothing is ever overwritten. Every frame that was ever written exists in a file in the chain. Range is bounded only by disk.

Circular. The ring wraps. When the write head reaches the end, it returns to the beginning and overwrites the oldest frames. The ring always holds the most recent N frames. Capture never stops. The oldest are always lost. Range is bounded by the size of the ring.

Cascade. Before a circular ring overwrites a frame, it copies that frame to another file. The frame survives. The circular ring reclaims the space. The frame now lives somewhere else — a larger ring, a different disk, a different storage class. Range is extended without growing the original ring.

Rules

Only circular displaces frames — so only circular can trigger a cascade. Archive never displaces. Archive never cascades. Archive is always terminal — the last ring in a chain, or the only ring.

Circular can cascade to another circular ring — extending the range across two rolling surfaces. Circular can cascade to archive — a rolling surface that never loses a frame because the archive catches everything before it is overwritten.

Chain as many circular rings as the environment demands. If the last ring is circular, frames that fall off the end are lost. If the last ring is archive, nothing is ever lost.

Tiers

Cascade promotes a frame to a tier. A tier is a location — a folder, a path, a storage destination. The tier determines where the files live physically. Tier 1 might be a folder on fast SSD. Tier 2 might be a folder on spinning disk. Tier 3 might be a folder on network storage.

Each tier has its own modality (archive or circular), its own capacity, and its own physical location. Cascade is what connects them. When a circular ring on one tier fills, the displaced frame promotes to the next tier — a different folder, a different disk, a different storage class.

Tiers manage not just how much range you have but where that range lives. The hot tier is small and fast. The cold tier is large and cheap. The frame flows from hot to cold as it ages. The tier structure matches storage resources to access patterns.

Compositions

A single archive tier. Every frame preserved in linear files growing on disk. The satellite corpus — nothing can be lost.

A single circular ring. Rolling window. The greenhouse corpus — recent readings matter, old readings do not.

A circular ring cascading to a larger circular ring. The greenhouse corpus — two rolling windows, extended range. But frames that fall off the last ring are still lost.

A circular ring cascading to archive. The financial corpus — hot queries hit the circular ring on SSD. Before any frame is overwritten, cascade copies it to archive on cheaper storage. The archive holds every transaction for the auditors. Nothing is ever lost.

Both corpora

The bifurcation from Lesson 201 applies. The main corpus and the system corpus each adapt independently. Different environments. Different constraints. Different compositions.

The main corpus might be circular cascading to archive — rolling hot range, permanent retention. The system corpus might be circular only — a rolling window of operational observations where last month's heartbeat has no value. Or the system corpus might be archive only — if regulations require a complete operational history.

Each corpus shapes itself to its own environment. The node holds two corpora. Each one adapted independently.