前言
springboot的自动任务注解@EnableScheduling和@Scheduled底层原理是默认是单线程的，所以，线上有自动任务突然不执行，肯定是有自动任务线程发生阻塞或者死锁，导致卡住了，其他自动任务都无法执行，对外呈现一个程序假死的情况。
jstack查看线程
jstack pid >jstack.log 打印堆栈日志。
css
"scheduling-1" #47 prio=5 os_prio=0 tid=0x00007f8f42840000 nid=0x6708 runnable [0x00007f8eb34f3000]
java.lang.Thread.State: RUNNABLE
at sun.nio.ch.FileDispatcherImpl.read0(Native Method)
at sun.nio.ch.SocketDispatcher.read(SocketDispatcher.java:39)
at sun.nio.ch.IOUtil.readIntoNativeBuffer(IOUtil.java:223)
at sun.nio.ch.IOUtil.read(IOUtil.java:197)
at sun.nio.ch.SocketChannelImpl.read(SocketChannelImpl.java:378)
- locked <0x0000000083919908> (a java.lang.Object)
at oracle.net.nt.TimeoutSocketChannel.read(TimeoutSocketChannel.java:174)
at oracle.net.ns.NSProtocolNIO.doSocketRead(NSProtocolNIO.java:560)
at oracle.net.ns.NIOPacket.readPayload(NIOPacket.java:308)
at oracle.net.ns.NIOPacket.readPacketFromSocketChannel(NIOPacket.java:212)
at oracle.net.ns.NIOPacket.readFromSocketChannel(NIOPacket.java:137)
at oracle.net.ns.NIOPacket.readFromSocketChannel(NIOPacket.java:110)
at oracle.net.ns.NIONSDataChannel.readDataFromSocketChannel(NIONSDataChannel.java:91)
at oracle.jdbc.driver.T4CMAREngineNIO.prepareForUnmarshall(T4CMAREngineNIO.java:791)
at oracle.jdbc.driver.T4CMAREngineNIO.unmarshalUB1(T4CMAREngineNIO.java:449)
at oracle.jdbc.driver.T4CTTIfun.receive(T4CTTIfun.java:410)
at oracle.jdbc.driver.T4CTTIfun.doRPC(T4CTTIfun.java:269)
at oracle.jdbc.driver.T4C8Oall.doOALL(T4C8Oall.java:655)
at oracle.jdbc.driver.T4CPreparedStatement.doOall8(T4CPreparedStatement.java:270)
at oracle.jdbc.driver.T4CPreparedStatement.fetch(T4CPreparedStatement.java:1079)
at oracle.jdbc.driver.OracleStatement.fetchMoreRows(OracleStatement.java:3456)
at oracle.jdbc.driver.InsensitiveScrollableResultSet.fetchMoreRows(InsensitiveScrollableResultSet.java:742)
at oracle.jdbc.driver.InsensitiveScrollableResultSet.absoluteInternal(InsensitiveScrollableResultSet.java:698)
at oracle.jdbc.driver.InsensitiveScrollableResultSet.next(InsensitiveScrollableResultSet.java:412)
- locked <0x000000008390a510> (a oracle.jdbc.driver.T4CConnection)
at com.p6spy.engine.wrapper.ResultSetWrapper.next(ResultSetWrapper.java:89)
at com.zaxxer.hikari.pool.HikariProxyResultSet.next(HikariProxyResultSet.java)
at org.hibernate.loader.Loader.processResultSet(Loader.java:986)
at org.hibernate.loader.Loader.doQuery(Loader.java:948)
at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:340)
at org.hibernate.loader.Loader.doList(Loader.java:2689)
at org.hibernate.loader.Loader.doList(Loader.java:2672)
at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2506)
at org.hibernate.loader.Loader.list(Loader.java:2501)
at org.hibernate.loader.criteria.CriteriaLoader.list(CriteriaLoader.java:109)
at org.hibernate.internal.SessionImpl.list(SessionImpl.java:1959)
at org.hibernate.internal.CriteriaImpl.list(CriteriaImpl.java:370)
at org.teamartframework.core.common.dao.impl.GenericBaseCommonDao.getListByCriteriaQuery(GenericBaseCommonDao.java:754)
at org.teamartframework.core.common.dao.impl.GenericBaseCommonDao$$FastClassBySpringCGLIB$$212185f1.invoke(<generated>)
at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:218)
at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:749)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:163)
at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:139)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:688)
at org.teamartframework.core.common.dao.impl.CommonDao$$EnhancerBySpringCGLIB$$575df7cd.getListByCriteriaQuery(<generated>)
at org.teamartframework.core.common.service.impl.CommonServiceImpl.getListByCriteriaQuery(CommonServiceImpl.java:290)
at com.test.service.base.impl.DeviceServiceImpl.getListByCriteriaQuery(DeviceServiceImpl.java:190)
at com.test.service.base.impl.DeviceServiceImpl.readData(DeviceServiceImpl.java:516)
at com.test.service.base.impl.DeviceServiceImpl$$FastClassBySpringCGLIB$$1b52e2d4.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.transaction.interceptor.TransactionInterceptor$$Lambda$573/569190647.proceedWithInvocation(Unknown Source)
at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:294)
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:98)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:688)
at com.test.service.base.impl.DeviceServiceImpl$$EnhancerBySpringCGLIB$$beeaba43.readData(<generated>)
at com.com.test.job.ReadJob.readData(ReadJob.java:32)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.springframework.scheduling.support.ScheduledMethodRunnable.run(ScheduledMethodRunnable.java:84)
at org.springframework.scheduling.support.DelegatingErrorHandlingRunnable.run(DelegatingErrorHandlingRunnable.java:54)
at org.springframework.scheduling.concurrent.ReschedulingRunnable.run(ReschedulingRunnable.java:93)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(ScheduledThreadPoolExecutor.java:180)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:293)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)从上面日志可以看出
csharp
at com.test.service.base.impl.DeviceServiceImpl.readData(DeviceServiceImpl.java:516)执行的比较慢，针对这个查询进行优化,问题解决了。
Spring Boot 定时器突然不执行原因
线程池满
Spring Boot 使用线程池来执行定时任务，默认情况下使用的是 ThreadPoolTaskScheduler，默认线程数量是1，如果定时任务的执行时间超过了线程池的容量，会导致线程池满，后续的任务无法执行。
可以修改默认线程池数量：
yaml
spring:
task:
scheduling:
pool:
size: 2任务抛出异常
如果定时任务在执行过程中抛出了异常并没有被捕获，那么该任务会停止执行，后续的任务也不会继续执行。
为了保证定时任务的连续执行，我们需要在任务执行过程中捕获异常并进行处理。可以在任务的执行方法中加入异常处理逻辑，将异常信息记录下来，以便后续分析和解决问题。
typescript
@Scheduled(cron = "0 0/5 * * * *")
public void executeTask() {
try {
// 执行任务逻辑
} catch (Exception e) {
// 记录异常信息
}
}定时任务的周期设置不合理
定时任务的周期设置不合理也可能导致任务停止执行。例如，如果我们将一个任务的执行周期设置为 5 秒，但任务的执行时间超过了 5 秒，那么任务就会停止执行。
总结
定时器突然停止执行可能是由线程池满、任务抛出异常和定时任务的周期设置不合理等原因引起的。为了解决这个问题，我们可以调整线程池的容量、捕获任务抛出的异常以及调整定时任务的周期。通过合理的设置和处理，我们可以保证定时任务的顺利执行。