Scheduling background tasks

ligero-scheduler runs periodic and one-off background jobs. Timing runs on a tiny daemon pool, but each task runs on its own virtual thread — so a slow job never stalls the timer, and a job that throws never cancels its own schedule (the error is logged, the schedule keeps ticking).

Install with the CLI

ligero add scheduler

implementation "com.ligeroframework:ligero-scheduler:$ligeroVersion"

Quick start

try (Scheduler scheduler = new Scheduler()) {
    scheduler.fixedRate(Duration.ofMinutes(5), cache::evictExpired);
    scheduler.dailyAt(LocalTime.of(3, 0), ZoneId.systemDefault(), reports::nightly);
    scheduler.once(Duration.ofSeconds(2), () -> log.info("warm-up done"));

    app.onStop(scheduler::close);   // stop jobs when the app stops
    app.start();
}

Register the Scheduler as a bean and the Beans container closes it on shutdown (it's AutoCloseable).

API

Method	Runs the task…
fixedRate(period, task)	every period, measured from each start
fixedDelay(delay, task)	repeatedly, waiting delay between completions
once(after, task)	once, after a delay
dailyAt(time, zone, task)	every day at a wall-clock time

Each returns a ScheduledTask with cancel().

Notes

• Virtual threads — the daemon pool only fires tasks; the work itself runs on a fresh virtual thread, so long/blocking jobs are cheap and never block the timer.
• Failures are isolated — an exception in a task is logged and the schedule continues (unlike a raw ScheduledExecutorService, which cancels on throw).
• Distributed schedules — this is in-process. For cluster-wide "run once across all instances", guard the task with a lock (e.g. a Redis key).