hashicorp/nomad · error

cannot destroy running task

Error message

cannot destroy running task

What it means

DestroyTask refuses to destroy a task whose handle reports IsRunning() unless force=true is passed. This is a safety guard so callers cannot accidentally destroy a live task and lose its state; the task must be stopped first, or destruction must be explicitly forced.

Source

Thrown at drivers/java/driver.go:653

	if err := handle.exec.Shutdown(signal, timeout); err != nil {
		if handle.pluginClient.Exited() {
			return nil
		}
		return fmt.Errorf("executor Shutdown failed: %v", err)
	}

	return nil
}

func (d *Driver) DestroyTask(taskID string, force bool) error {
	handle, ok := d.tasks.Get(taskID)
	if !ok {
		return drivers.ErrTaskNotFound
	}

	if handle.IsRunning() && !force {
		return fmt.Errorf("cannot destroy running task")
	}

	if !handle.pluginClient.Exited() {
		if err := handle.exec.Shutdown("", 0); err != nil {
			handle.logger.Error("destroying executor failed", "error", err)
		}

		handle.pluginClient.Kill()
	}

	d.tasks.Delete(taskID)
	return nil
}

func (d *Driver) InspectTask(taskID string) (*drivers.TaskStatus, error) {
	handle, ok := d.tasks.Get(taskID)
	if !ok {
		return nil, drivers.ErrTaskNotFound

View on GitHub (pinned to 482b49bf1a)

Solutions

1. Call StopTask (or DestroyTask with force=true) instead
2. If you intend to discard a running task, pass force=true — the driver will then shut the executor down before cleanup
3. If the task is actually dead but still reported running, check plugin client state and force-destroy to clear the stale handle
4. Fix any earlier StopTask failure (e.g. hung JVM) so normal stop/destroy ordering works

Example fix

// before: destroys a running task without stopping it
err := driver.DestroyTask(taskID, false)
// after: stop first, then destroy
if err := driver.StopTask(taskID, "SIGINT", 30*time.Second); err != nil {
    // log and proceed to force-destroy
}
err := driver.DestroyTask(taskID, true)

// check task state before destroying
if driver.IsRunning(taskID) {
    if err := driver.StopTask(taskID, "SIGINT", 30*time.Second); err != nil {
        // log and continue to forced destroy
    }
}
err := driver.DestroyTask(taskID, true)

func canDestroy(d *drivers.Driver, taskID string, force bool) bool {
    return force || !d.IsRunning(taskID)
}

if err := driver.DestroyTask(taskID, force); err != nil {
    if strings.Contains(err.Error(), "cannot destroy running task") {
        _ = driver.StopTask(taskID, "SIGINT", 30*time.Second)
        err = driver.DestroyTask(taskID, true)
    }
    return err
}

When it happens

Trigger: Calling Driver.DestroyTask(taskID, force=false) (or equivalent GC path) while handle.IsRunning() is true — the executor is still up and the task has not been stopped — and the driver returns this plain error before any shutdown attempt.

Common situations: Operators or tooling calling destroy/GC out of order (destroy before stop), a StopTask that failed earlier leaving the task running, or automation invoking force=false destroy during cleanup.

Related errors

• cannot destroy running task
• users: release of unused uid/gid
• pre-run hook %q failed: %v
• update hook %q failed: %v
• plugin group already shutdown

AI-assisted analysis of hashicorp/nomad@482b49bf1a (2026-09-04). Data as JSON: /api/errors/ab69b25260539afd. Report an issue: GitHub.