Maglev Cycle 11: CockroachDB Score Write

The Context

With causal ordering confirmed in Cycle 10 and the DB connection verified in Cycle 4, Cycle 11 activates persistence: the persona zone commits the score and multiplayer-fabric-uro writes it to CockroachDB.

The Problem Statement

The cross-zone write path — persona zone commits, uro writes via Ecto over Fly’s 6PN using the gateway_writer role — requires end-to-end validation. With causal ordering confirmed in Cycle 10, the only remaining unknown is whether the database write path performs correctly under mission load.

Design

On each core-slot event the persona zone commits the score update after the VClock.le check passes. On mission end multiplayer-fabric-uro writes the committed score to CockroachDB via Ecto over Fly’s 6PN using the gateway_writer role. RelReplica entries stamped with sentAt are broadcast to the interest band.

Write path:

spatial zone  →  QueueOp(VClock)  →  persona zone commits
              →  uro → CockroachDB (gateway_writer, Fly 6PN)
              →  RelReplica(sentAt) broadcast to interest band

Pass criteria:

Estimate

5 days (2026-06-30 → 2026-07-07). The Ecto write path to CockroachDB is proven in Cycle 4; the work is the persona zone commit flow, VClock gating on the write side, and RelReplica broadcast. No prior end-to-end causal write exists in the history.

CRIS Score

Factor Score Evidence
Complexity 6 The Ecto write path to CockroachDB over Fly’s 6PN under concurrent mission load is untested in this codebase.
Reach 10 Persistent player progression requires this path.
Impediment 8 A broken score write does not block Cycle 10 gameplay but blocks any feature that depends on persistent state.
Stakeholder 10 Required for the full Maglev Intercept scenario.
Total 8.0 Build after Cycles 10 and 9 pass.

The Downsides

If the persona zone goes down, that player’s attributes are offline until it recovers. Replication factor ≥ 2 on the persona partition is the mitigation, deferred to a later cycle.

The Road Not Taken

Writing scores directly from the spatial zone to CockroachDB was considered. Rejected — it violates DisjointRanges and allows concurrent writes to the same player record.

Status

Status: Draft

Decision Makers

  • Lead Architect / Fabric Maintainer

Tags

  • maglev-cycle-11, db-write, persona-zone, cockroachdb, galls-law, 20260506-maglev-cycle-11-db-write, present-proposal-template

Further Reading

@misc{v_sekai_2026,
  title = {V-Sekai},
  year  = {2026},
  url   = {https://v-sekai.org/}
}