apache/pulsar · error · IllegalArgumentException

Not support to set continueExistingPeriodicTasksAfterShutdow

Error message

Not support to set continueExistingPeriodicTasksAfterShutdownPolicy, it is always false

What it means

SingleThreadNonConcurrentFixedRateScheduler always behaves as if continueExistingPeriodicTasksAfterShutdownPolicy is false: after shutdown, periodic tasks are never continued. Therefore the inherited setContinueExistingPeriodicTasksAfterShutdownPolicy method unconditionally throws IllegalArgumentException to reject any attempt to change this fixed policy.

Source

Thrown at pulsar-common/src/main/java/org/apache/pulsar/common/util/SingleThreadNonConcurrentFixedRateScheduler.java:199

     * Long.MAX_VALUE.
     */
    private long overflowFree(long delay) {
        Delayed head = (Delayed) super.getQueue().peek();
        if (head != null) {
            long headDelay = head.getDelay(NANOSECONDS);
            if (headDelay < 0 && (delay - headDelay < 0)) {
                delay = Long.MAX_VALUE + headDelay;
            }
        }
        return delay;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public void setContinueExistingPeriodicTasksAfterShutdownPolicy(boolean flag) {
        throw new IllegalArgumentException("Not support to set continueExistingPeriodicTasksAfterShutdownPolicy, it is"
                + " always false");
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public boolean getContinueExistingPeriodicTasksAfterShutdownPolicy() {
        return false;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public void setExecuteExistingDelayedTasksAfterShutdownPolicy(boolean flag) {
        throw new IllegalArgumentException("Not support to set executeExistingDelayedTasksAfterShutdownPolicy, it is"
                + " always false");

View on GitHub (pinned to 820761864e)

Solutions

Remove the call to setContinueExistingPeriodicTasksAfterShutdownPolicy; the scheduler intentionally never continues periodic tasks after shutdown.
Adjust generic scheduler-configuration code to skip this policy for this scheduler type (e.g. instanceof check or capability flag).
If post-shutdown execution of periodic tasks is required, use a plain ScheduledThreadPoolExecutor instead of this scheduler.
Handle the IllegalArgumentException defensively if the call site must stay source-compatible with multiple scheduler types.

Example fix

// before
scheduler.setContinueExistingPeriodicTasksAfterShutdownPolicy(true);
// after
if (!(scheduler instanceof SingleThreadNonConcurrentFixedRateScheduler)) {
    scheduler.setContinueExistingPeriodicTasksAfterShutdownPolicy(true);
}

Defensive patterns

Strategy: try-catch

Validate before calling

static boolean supportsShutdownPolicies(java.util.concurrent.ScheduledExecutorService s) {
    return !(s instanceof org.apache.pulsar.common.util.SingleThreadNonConcurrentFixedRateScheduler);
}

Type guard

static boolean isPolicyConfigurable(java.util.concurrent.ScheduledExecutorService s) {
    return s instanceof java.util.concurrent.ScheduledThreadPoolExecutor;
}

Try / catch

try {
    scheduler.setContinueExistingPeriodicTasksAfterShutdownPolicy(flag);
} catch (IllegalArgumentException e) {
    LOG.info("Scheduler {} does not support shutdown policy override: {}", scheduler, e.getMessage());
}

Prevention

Do not call shutdown-policy setters on SingleThreadNonConcurrentFixedRateScheduler — the policies are fixed to false
Gate generic executor-tuning code with instanceof ScheduledThreadPoolExecutor checks
If post-shutdown periodic execution is a requirement, choose ScheduledThreadPoolExecutor instead
Document in executor configuration utilities which policy calls are optional/unsupported

When it happens

Trigger: Calling setContinueExistingPeriodicTasksAfterShutdownPolicy(true or false) on a SingleThreadNonConcurrentFixedRateScheduler instance, typically in code that configures a ScheduledExecutorService generically and applies this policy tuning call to any scheduler.

Common situations: Framework or utility code that customizes ScheduledExecutorService instances (e.g. copied ThreadPoolExecutor tuning snippets) invokes the setter on this custom scheduler; migration of code that used ScheduledThreadPoolExecutor to this Pulsar scheduler.

Related errors

AI-assisted analysis of apache/pulsar@820761864e (2026-09-06). Data as JSON: /api/errors/00d6a5008b089eb4. Report an issue: GitHub.