Flush Control

Fine-grained control over how the queue is flushed when connectivity is restored.

Why

Dozens or hundreds of jobs can accumulate offline. Sending them all simultaneously could overwhelm the server. flushOption controls concurrency and batch intervals.

flushOption


const saveAction = actionOptions({
  actionKey: 'save',
  request: (input) => api.save(input),
  flushOption: {
    concurrency: 3,      // max 3 concurrent
    intervalMs: 500,      // 500ms between batches
  },
});

Fields

Field	Type	Default	Description
`concurrency`	`number`	`Infinity`	Max concurrent jobs
`intervalMs`	`number`	`0`	Delay after each batch (ms)

Behavior


Queue: [A, B, C, D, E]  (concurrency: 2, intervalMs: 500)

Batch 1: [A, B] execute → 500ms wait
Batch 2: [C, D] execute → 500ms wait
Batch 3: [E] execute → done

Batching happens within each action
Different actions execute in parallel
Jobs within a batch run via Promise.allSettled

Global defaults + per-action

Set global defaults in ConnectivityProvider, override per-action:


<ConnectivityProvider
  detectors={[...]}
  defaultOptions={{
    actions: {
      flushOption: { concurrency: 5 },
    },
  }}
>
  <App />
</ConnectivityProvider>

Per-action settings override global defaults. If not set, global defaults apply. Both concurrency and intervalMs follow the same rule.

dedupeOnFlush

Dedupe strategy applied at flush time for jobs with the same dedupeKey.


const saveAction = actionOptions({
  actionKey: 'save',
  request: (input) => api.save(input),
  dedupeKey: (input) => input.id,
  dedupeOnFlush: 'keep-last',
});

Strategy	Description
`'keep-first'`	Keep earliest enqueued job, cancel rest
`'keep-last'`	Keep latest enqueued job, cancel rest

When to use

Standard dedupe (dedupeKey) operates at enqueue time. But retry failures can leave multiple jobs with the same key. dedupeOnFlush cleans up right before flush.

Example


Queue: [save:1 (v1), save:1 (v3)]  ← same key from retry failures

dedupeOnFlush: 'keep-last'
→ save:1 (v1) canceled → only save:1 (v3) executes

dedupeOnFlush: 'keep-first'
→ save:1 (v3) canceled → only save:1 (v1) executes