失败告警策略扩展：默认提供邮件失败告警，可扩展短信等，扩展代码位置为 "JobFailMonitorHelper.failAlarm"；

doc/XXL-JOB官方文档.md

 ### 6.20 版本 V1.9.0 特性[迭代中]
 - 1、新增任务运行模式 "GLUE模式(NodeJS) "，支持NodeJS脚本任务；
 - 2、修复任务监控线程被耗时任务阻塞的问题；
+- 3、失败告警策略扩展：默认提供邮件失败告警，可扩展短信等，扩展代码位置为 "JobFailMonitorHelper.failAlarm"；
 
 ### TODO LIST
 - 1、任务权限管理：执行器为粒度分配权限，核心操作校验权限；

xxl-job-admin/src/main/java/com/xxl/job/admin/core/thread/JobFailMonitorHelper.java

 								}
 								if (ReturnT.FAIL_CODE == log.getTriggerCode() || ReturnT.FAIL_CODE == log.getHandleCode()) {
 									// job fail,
-									sendMonitorEmail(log);
+									failAlarm(log);
 									logger.info(">>>>>>>>>>> job monitor, job fail, JobLogId:{}", jobLogId);
 								}
 							}
 						XxlJobLog log = XxlJobDynamicScheduler.xxlJobLogDao.load(jobLogId);
 						if (ReturnT.FAIL_CODE == log.getTriggerCode()|| ReturnT.FAIL_CODE==log.getHandleCode()) {
 							// job fail,
-							sendMonitorEmail(log);
+							failAlarm(log);
 							logger.info(">>>>>>>>>>> job monitor last, job fail, JobLogId:{}", jobLogId);
 						}
 					}
 	}
 
 	/**
-	 * send monitor email
+	 * fail alarm
+	 *
 	 * @param jobLog
 	 */
-	private void sendMonitorEmail(XxlJobLog jobLog){
+	private void failAlarm(XxlJobLog jobLog){
+
+		// send monitor email
 		XxlJobInfo info = XxlJobDynamicScheduler.xxlJobInfoDao.loadById(jobLog.getJobId());
 		if (info!=null && info.getAlarmEmail()!=null && info.getAlarmEmail().trim().length()>0) {
 
 				MailUtil.sendMail(email, title, content, false, null);
 			}
 		}
+
+		// TODO, custom alarm strategy, such as sms
+
 	}
 
 	public void toStop(){