activiti的serviceTask失败重试

##需求 serviceTask失败以后，指望可以自动重试。 ##配置

<serviceTask activiti:async="true" activiti:exclusive="false" activiti:expression="${demoService.getSentence(execution)}" id="demoServiceTask" name="demoServiceTask">
      <extensionElements>
        <activiti:failedJobRetryTimeCycle>R5/PT1M</activiti:failedJobRetryTimeCycle>
      </extensionElements>
    </serviceTask>

• 配置async为true
• 配置重试次数为每一个1分钟重试一次，总共重试5次 ##docs
• Custom Fail Retry configuration

activiti:failedJobRetryTimeCycleR5/PT7M</activiti:failedJobRetryTimeCycle>

• service-task-async及retry配置

• Re: Handling erros in Process Instances. How to retry a failed step?