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Parallel actions

parallel() runs several actions concurrently — as queued jobs, or inline under runSync — and returns their results as a list in declaration order:

[$pricing, $inventory, $reviews] = $this->parallel()
    ->action(FetchPricing::class, $sku)
    ->action(FetchInventory::class, $sku)
    ->action(FetchReviews::class, $sku)
    ->failFast()
    ->run();

Failure policy​

ParallelFailurePolicy controls what happens when a step fails:

  • failFast() (default, ParallelFailurePolicy::FailFast) — cancel the block on the first hard failure; pending siblings never start.
  • waitAllThenFail() — let every step settle before the block fails.

The default comes from parallel.default_failure_policy in config.

Per-step options​

Steps in a parallel block are full builders — they can carry compensations, deadlines, and optional behaviour:

[$a, $b] = $this->parallel()
    ->action(ReserveSeat::class, $id)
        ->compensateWith(ReleaseSeat::class, $id)
    ->optionalAction(FetchRecommendations::class, $id)
        ->fallbackValueOnFail([])
    ->waitAllThenFail()
    ->run();

When a parallel block fails, any completed steps that registered compensations are rolled back, just like a sequential saga. See Sagas & compensations and Optional actions.