Recurring Timers are called concurrently

Test case @Singleton @Lock(LockType.READ) @Startup public class MyScheduler { private static final Logger LOGGER = Logger.getLogger(MyScheduler. class. getName()); @Schedule(hour = "*" , minute = "*" , second = "0/30" ) public void performOperation() { try { String id = UUID.randomUUID().toString(); Object [] params = new Object []{id,LocalDateTime.now(), Thread .currentThread().getName()}; LOGGER.log(Level.INFO, "Starting operation {0} at {1} in thread {2} " , params); long pause= Duration.ofMinutes(1).toMillis(); Thread .sleep(pause); LOGGER.info( "Done performing operation: " + id); } catch (InterruptedException ex) { LOGGER.log(Level.SEVERE, null , ex); } } }