ADR-0004: DSM memory fabric (ChimeraMEM)

Status

Accepted

Context

Shared working sets and live Wasm migration need a unified address space without kernel RDMA.

Decision

Implement a portable soft page-table DSM over QUIC. Linux may enable userfaultfd behind --features userfaultfd. Consistency knobs: CRDT regions (vector clocks, G-Counter, OR-Set) vs ownership leases for linearizable pages. Tiering: HotRam → PeerCache → ColdFs (+ GPU hints).

Consequences

• Works on Windows for demos.
• Page faults fetch over bulk streams; control plane stays prioritized.
• Migration packetizes linear memory (XOR deltas available for similar pages).