微服务静默失败，在计划任务中发生意外错误

Question

一种微服务，该服务定期使用基于复合索引的分页对mongodb的数据进行轮询。该微型计算机运行在512MB内存上。几个小时后，可以看到以下日志，这些日志对调试问题没有太多帮助

   Unexpected error occurred in scheduled task., Trace=
   at com.myPkg.DocumentBuilderService.getValidKey(DocumentBuilderService.java:104);
   at com.myPkg.DocumentBuilderService.processDocument(DocumentBuilderService.java:67);
   at com.myPkg.DocumentDbServiceImpl.getDocuments(DocumentDbServiceImpl.java:193);
   at com.myPkg.PollerService.pollDocuments(PollerService.java:39);
   at com.myPkg.PollerService$$FastClassBySpringCGLIB$$43e406ce.invoke(<generated>);       
   at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:218);
   at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:749);
   at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:163);
   at org.springframework.aop.aspectj.MethodInvocationProceedingJoinPoint.proceed(MethodInvocationProceedingJoinPoint.java:88);
   at org.springframework.cloud.sleuth.instrument.scheduling.TraceSchedulingAspect.traceBackgroundThread(TraceSchedulingAspect.java:68);