How Walrus Prevents Reconfiguration Race Conditions with Red Stuff
Epoch transitions create natural race conditions. A write issued just before the epoch boundary might target either the old or new committee. A read requested during transition might find data on old validators but not new ones. These races are sources of complexity and inconsistency.
Red Stuff's two-dimensional structure eliminates this ambiguity through deterministic mapping. Every blob has a single epoch—the epoch during which it was written. That epoch determines its committee assignment. The blob's grid position and epoch together uniquely identify which validators hold which fragments.
There is no ambiguity about blob ownership.
A blob written in epoch E goes to committee E, period. A blob cannot "belong to both committees" or "transition gradually." Its epoch is immutable, recorded on-chain. The committee holding it is deterministic.
Writes issued at the epoch boundary are unambiguous. The client's clock, matching Sui's finalized epoch, determines which committee receives the write. If the write is submitted and finalized in epoch E, it belongs to committee E. If delayed and finalized in epoch E+1, it belongs to committee E+1. The on-chain timestamp is the source of truth.
Reads are similarly unambiguous. The blob's epoch is known from the PoA. The current epoch is known from Sui's consensus. If they match, read from the current committee. If the blob is historical, read from the archive.
There is no guessing or negotiation.
This determinism is possible because Red Stuff doesn't blur blob membership. Each blob has one epoch, one committee, one grid structure. Race conditions cannot exist when assignment is cryptographically deterministic and on-chain anchored.