Scheduling Tasks

Introduction

@Scheduled runs methods on a cron or fixed-rate schedule. Great for cleanups, syncs, daily reports — bad for distributed jobs (use Quartz or a queue when you have N replicas).

Informative example

@Configuration @EnableScheduling
public class SchedulingConfig {}

@Component
@RequiredArgsConstructor
public class CleanupJob {
  private final OrderRepository orders;

  // every day at 02:00
  @Scheduled(cron = "0 0 2 * * *", zone = "UTC")
  public void purgeOldDrafts() {
    int n = orders.deleteDraftsOlderThan(Instant.now().minus(30, ChronoUnit.DAYS));
    log.info("Purged {} draft orders", n);
  }
}

Best practices

• Single-replica only — @Scheduled runs on every instance otherwise.
• Multi-replica → ShedLock + DB/Redis lock, or Quartz cluster.
• Make jobs idempotent; nothing breaks if the same one runs twice.