Quarkus Skill

Scheduled Methods

• @Scheduled(every = "10s") — run every 10 seconds.
• @Scheduled(cron = "0 0 * * * ?") — cron expression (every hour).
• @Scheduled(delayed = "5s") — initial delay before first execution.
• Methods must return void or Uni<Void> and take no arguments (or ScheduledExecution).

Programmatic Scheduling

• Inject Scheduler to pause, resume, or create jobs programmatically.
• Use scheduler.newJob("my-job").setInterval("10s").setTask(ctx -> ...).schedule().

Concurrent Execution

• By default, a scheduled method CAN run concurrently with itself.
• Use @Scheduled(concurrentExecution = SKIP) to prevent concurrent runs.

Testing

• Use @QuarkusTest — scheduled methods run during tests.
• Disable scheduling in tests if not needed: quarkus.scheduler.enabled=false.

Common Pitfalls

• Scheduled methods must be on CDI beans — plain classes are ignored.
• Do NOT use @Scheduled on private methods.