Triple-Write Orchestrator

The TripleWriteOrchestrator (lib/triple-write-orchestrator.ts) is a Saga-pattern implementation that coordinates multi-step write operations with automatic rollback on failure.

The Three Steps

Every user action that modifies data must write to three independent systems in strict sequence:

Step	Target	Timeout	Compensating Function
1	Convex Cloud Mutation	15s	Convex rollback mutation
2	Local SQLite Write	15s	SQLite delete
3	Hardware Alarm Sync	15s	None (idempotent)

Usage

const saga = new TripleWriteOrchestrator(context);

saga
  .addStep("Convex Mutation",
    async (ctx) => await convexMutation(ctx),
    async (ctx, result) => await convexRollback(result)
  )
  .addStep("Local SQLite Write",
    async (ctx, prev) => await sqliteInsert(prev),
    async (ctx, result) => await sqliteDelete(result)
  )
  .addStep("Hardware Alarm Sync",
    async (ctx) => await scheduleNextAlarm()
  );

const { success, error, rollbackFailed } = await saga.execute();

Per-Step Timeouts

Each step races against its own timeout via Promise.race. If a Convex mutation hangs due to a slow network, the timeout fires and the orchestrator skips to the rollback phase.

Rollback Behavior

Steps are rolled back in reverse order. If Step 2 fails, Step 1’s compensating function runs. If a compensating function itself fails, the rollbackFailed flag is set, signaling HydrationSync to perform a full reconciliation on the next cycle.

Saga Tracking

Each orchestrator instance generates a unique saga ID for log correlation:

[Saga:X7K2M1] Initiating 3-stage sequence...
[Saga:X7K2M1] Phase: Convex Mutation (timeout: 15000ms)
[Saga:X7K2M1] Phase: Local SQLite Write (timeout: 15000ms)
[Saga:X7K2M1] SUCCESS: All layers committed.