object : Task("task one") {
        val schedules = mutableListOf(200.µs)

        override fun runOnce(): Long {
          if (schedules.isNotEmpty()) {
            redQueue.schedule(this, schedules.removeAt(0)) // Add it at the end also.
          }
          log += "scheduledTasks=${redQueue.scheduledTasks}"
          return -1L
        }
      }
    redQueue.schedule(task, 100.µs)

    // If the task is already scheduled, take the earlier of the two times.
    val existingIndex = futureTasks.indexOf(task)
    if (existingIndex != -1) {
      if (task.nextExecuteNanoTime <= executeNanoTime) {
        taskRunner.logger.taskLog(task, this) { "already scheduled" }
        return false
      }
      futureTasks.removeAt(existingIndex) // Already scheduled later: reschedule below!
    }

      private ScheduledFuture<@Nullable Void> submitToExecutor(Schedule schedule) {
        return executor.schedule(this, schedule.delay, schedule.unit);
      }
    }

    /**
     * Contains the most recently submitted {@code Future}, which may be cancelled or updated,
     * always under a lock.
     */
    private static final class SupplantableFuture implements Cancellable {
      private final ReentrantLock lock;

      private ScheduledFuture<@Nullable Void> submitToExecutor(Schedule schedule) {
        return executor.schedule(this, schedule.delay, schedule.unit);
      }
    }

    /**
     * Contains the most recently submitted {@code Future}, which may be cancelled or updated,
     * always under a lock.
     */
    private static final class SupplantableFuture implements Cancellable {
      private final ReentrantLock lock;

│   └── job/                   # Background jobs
├── api/                       # REST API endpoints
├── opensearch/                # OpenSearch integration
│   ├── config/                # Config index (crawl configs, schedules)
│   ├── log/                   # Log index
│   ├── user/                  # User index
│   ├── exbhv/                 # Extended behaviors (repositories)
│   └── exentity/              # Extended entities (domain models)

   *     remote server accepted the request before the failure.
   * @throws IllegalStateException when the call has already been executed.
   */
  @Throws(IOException::class)
  fun execute(): Response

  /**
   * Schedules the request to be executed at some point in the future.
   *
   * The [dispatcher][OkHttpClient.dispatcher] defines when the request will run: usually

        this.asyncNotifyTasks = new ConcurrentHashMap<>();
        this.scheduler = Executors.newScheduledThreadPool(3); // Increased for async notifications
        this.rpcClient = rpcClient;

        // Schedule periodic tasks
        schedulePeriodicTasks();
    }

    /**
     * Schedules periodic tasks for heartbeat and registration monitoring.
     */

### Go-Live

- [ ] Schedule maintenance window
- [ ] Final incremental data sync
- [ ] Switch DNS or endpoints to Fess
- [ ] Monitor logs for errors
- [ ] Monitor search performance metrics
- [ ] Have rollback plan ready

### Post-Migration

- [ ] Monitor search quality and relevance
- [ ] Tune ranking and boosting settings
- [ ] Set up regular crawl schedules
- [ ] Configure backup and disaster recovery

replication rules were disabled will be synced to the target cluster. Depending on the number of previously existing objects, the existing objects that are now eligible to be replicated will eventually be synced to the target cluster as the scanner schedules them. This may be slower depending on the load on the cluster, latency and size of the namespace.

In the rare event that target DR site is entirely lost and previously replicated objects to the DR cluster need to be re-replicated, `mc...

    Future<?> scheduled = executorService.schedule(task, delay, timeUnit);
    /*
     * Even when the user interrupts the task, we pass `false` to `cancel` so that we don't
     * interrupt a second time after the interruption performed by TrustedListenableFutureTask.
     */
    task.addListener(() -> scheduled.cancel(false), directExecutor());
    return task;
  }

  /**