Harel Statecharts, Event Sourcing & Distributed Sagas

In This Component

In distributed multi-warehouse fulfillment, two-phase commit (2PC) locks destroy throughput under peak arrival surges, while uncoordinated microservices create “zombie” locked inventory whenever a downstream carrier API times out.

ASC 606-Aligned Distributed Saga Coordinator

Project Aegis implements the Garcia-Molina & Salem Process Manager Saga pattern aligned with GAAP ASC 606 revenue recognition:

1. $\text{T0}$ (VerifyAuthHold): Verifies customer payment authorization before touching physical inventory.
2. $\text{T1}$ (ReserveStock): Executes a version-tagged Optimistic Concurrency Control (OCC) atomic update on geographic shard $k$:

UPDATE inventory
SET allocated = allocated + :q, version = version + 1
WHERE node_k = :k AND sku_i = :i
  AND (on_hand - allocated) >= :q
  AND version = :expected_version;

3. $\text{T2}$ (BookFreightCarrier): Requests carrier manifest and shipping label. If $\text{T2}$ fails, compensating action $\text{C1}$ (ReleaseInventoryAllocation) immediately frees the reserved units with cryptographic idempotency (sha256(order_id + step_id)).
4. $\text{T3}$ (CaptureAndSettleASC606): Captures funds and recognizes GAAP revenue strictly upon carrier dispatch satisfaction.

Orthogonal Harel Statecharts & Bit-for-Bit Replay Determinism

Concurrent state transitions across the Order Lifecycle (Pending $\to$ Allocated $\to$ Dispatched $\to$ Settled / Compensated) and Inventory Lifecycle (Available $\to$ Allocated $\to$ Shipped $\to$ Replenished) are governed by deterministic Harel statecharts.

Every immutable event in the append-only ledger carries a deterministic counter-based PRNG key (philox_key = hash(trace_id, event_seq_id)), ensuring that the state fold

$S_T={⨁}_{t=0}^T\text{apply}(S_t,E_t)$

reproduces identical Sequential Monte Carlo (SMC) particle resampling trajectories across historical replays.