/** The key of the configuration. e.g. org.codelibs.fess.app.job.ScriptExecutorJob */
    String SCHEDULER_JOB_CLASS = "scheduler.job.class";

    /** The key of the configuration. e.g. QUIT */
    String SCHEDULER_CONCURRENT_EXEC_MODE = "scheduler.concurrent.exec.mode";

    /** The key of the configuration. e.g. 30 */
    String SCHEDULER_MONITOR_INTERVAL = "scheduler.monitor.interval";