Java 重新启动quartz计划程序而不出现错误

上下文

我正在尝试使用jdbc在集群模式下使用quartz调度程序

问题

在集群模式下使用jdbc之前，我只是使用RAM存储测试了调度器。这没有问题，我能够重新启动调度程序（主类），没有任何错误。我现在遇到的问题是，当我停止执行（ctrl+c）然后重新启动时，总是会收到错误消息：

org.quartz.ObjectAlreadyExistsException: Unable to store Job : 'MyTestJob', because one already exists with this identification.

我不明白这里发生了什么。quartz不支持重新启动计划程序吗？我的意思是，如果发生崩溃，并且计划程序在恢复后重新启动，会发生什么？是从quartz数据库中删除作业的唯一选项吗？也许还有另一种方法或者我错过了什么。我觉得使用一个不能处理重启的库不是很舒服

另一件奇怪的事情是，当切换到jdbc时，我的作业不再被触发，我只看到数据库中等待的状态。这会是什么？作业（cron计划）在RAM模式下正常工作

对于这个简单任务中遇到的文档级别和问题，我感到有点惊讶，因为我已经听说quartz调度器很多年了，但从未使用过它。古德建议，我不是唯一一个有这个问题的人。我希望这只是我的问题，并且我的问题有一个简单的解决方案，否则在2.2.x版本中第一次尝试这个库，并且已经不得不寻找其他东西，这将是非常令人失望的

以下是我的配置：

#============================================================================
# Configure Main Scheduler Properties  
#============================================================================

org.quartz.scheduler.skipUpdateCheck = true
org.quartz.scheduler.instanceName = Test-Scheduler
org.quartz.scheduler.instanceId = AUTO

#============================================================================
# Configure ThreadPool  
#============================================================================

org.quartz.threadPool.class = org.quartz.simpl.SimpleThreadPool
org.quartz.threadPool.threadCount = 25
org.quartz.threadPool.threadPriority = 5

#============================================================================
# Configure JobStore  
#============================================================================

org.quartz.jobStore.misfireThreshold = 60000

org.quartz.jobStore.class = org.quartz.impl.jdbcjobstore.JobStoreTX
org.quartz.jobStore.driverDelegateClass = org.quartz.impl.jdbcjobstore.StdJDBCDelegate
org.quartz.jobStore.useProperties = true
org.quartz.jobStore.dataSource = quartzDS
org.quartz.jobStore.tablePrefix = QRTZ_

org.quartz.jobStore.isClustered = true
org.quartz.jobStore.clusterCheckinInterval = 20000

这是我的密码：

    SchedulerFactory sf = new StdSchedulerFactory();
    Scheduler scheduler = sf.getScheduler();

    scheduler.start();

                JobDetail jobDetail = newJob(job.getClass())
                    .withIdentity("test-name", "test-group")
                    .build();

                CronTrigger trigger = newTrigger()
                    .withIdentity("test-name-trigger", "test-group")
                    .withSchedule(cronSchedule("0 0/1 * * * ?"))
                    .build();

                scheduler.scheduleJob(jobDetail, trigger);

                System.out.println(trigger.getNextFireTime());

编辑

这很有趣

1） RAM模式有效

2） 启用集群的jdbc无法工作，并且（几乎）以静默方式失败-即使启用了日志记录。在日志输出中，我看到以下内容：

19:57:29,913  INFO StdSchedulerFactory:1184 - Using default implementation for ThreadExecutor
19:57:29,936  INFO SchedulerSignalerImpl:61 - Initialized Scheduler Signaller of type: class org.quartz.core.SchedulerSignalerImpl
19:57:29,936  INFO QuartzScheduler:240 - Quartz Scheduler v.2.2.1 created.
19:57:29,938  INFO JobStoreTX:667 - Using db table-based data access locking (synchronization).
19:57:29,940  INFO JobStoreTX:59 - JobStoreTX initialized.
19:57:29,941  INFO QuartzScheduler:305 - Scheduler meta-data: Quartz Scheduler (v2.2.1) 'Test-Scheduler' with instanceId 'Michael-PC1405447049916'
  Scheduler class: 'org.quartz.core.QuartzScheduler' - running locally.
  NOT STARTED.
  Currently in standby mode.
  Number of jobs executed: 0
  Using thread pool 'org.quartz.simpl.SimpleThreadPool' - with 25 threads.
  Using job-store 'org.quartz.impl.jdbcjobstore.JobStoreTX' - which supports persistence. and is clustered.

19:57:29,941  INFO StdSchedulerFactory:1339 - Quartz scheduler 'Test-Scheduler' initialized from default resource file in Quartz package: 'quartz.properties'
19:57:29,941  INFO StdSchedulerFactory:1343 - Quartz scheduler version: 2.2.1
19:57:29,995  INFO AbstractPoolBackedDataSource:462 - Initializing c3p0 pool... com.mchange.v2.c3p0.ComboPooledDataSource [ acquireIncrement -> 3, acquireRetryAttempts -> 30, acquireRetryDelay -> 1000, autoCommitOnClose -> false, automaticTestTable -> null, breakAfterAcquireFailure -> false, checkoutTimeout -> 0, connectionCustomizerClassName -> null, connectionTesterClassName -> com.mchange.v2.c3p0.impl.DefaultConnectionTester, dataSourceName -> 1hgeby993gf1xpdmdc44s|7ec4d0, debugUnreturnedConnectionStackTraces -> false, description -> null, driverClass -> com.mysql.jdbc.Driver, factoryClassLocation -> null, forceIgnoreUnresolvedTransactions -> false, identityToken -> 1hgeby993gf1xpdmdc44s|7ec4d0, idleConnectionTestPeriod -> 50, initialPoolSize -> 3, jdbcUrl -> jdbc:mysql://localhost:3306/scheduler, maxAdministrativeTaskTime -> 0, maxConnectionAge -> 0, maxIdleTime -> 0, maxIdleTimeExcessConnections -> 0, maxPoolSize -> 5, maxStatements -> 0, maxStatementsPerConnection -> 120, minPoolSize -> 1, numHelperThreads -> 3, numThreadsAwaitingCheckoutDefaultUser -> 0, preferredTestQuery -> SELECT 1 FROM QRTZ_JOB_DETAILS, properties -> {user=******, password=******}, propertyCycle -> 0, testConnectionOnCheckin -> true, testConnectionOnCheckout -> false, unreturnedConnectionTimeout -> 0, usesTraditionalReflectiveProxies -> false ]
19:57:30,243 DEBUG StdRowLockSemaphore:107 - Lock 'TRIGGER_ACCESS' is desired by: main
19:57:30,262 DEBUG StdRowLockSemaphore:92 - Lock 'TRIGGER_ACCESS' is being obtained: main
19:58:21,328 DEBUG StdRowLockSemaphore:141 - Lock 'TRIGGER_ACCESS' was not obtained by: main - will try again.
19:58:22,329 DEBUG StdRowLockSemaphore:92 - Lock 'TRIGGER_ACCESS' is being obtained: main
19:59:13,389 DEBUG StdRowLockSemaphore:141 - Lock 'TRIGGER_ACCESS' was not obtained by: main - will try again.
19:59:14,389 DEBUG StdRowLockSemaphore:92 - Lock 'TRIGGER_ACCESS' is being obtained: main

尽管如此，就在我即将再次启用群集模式时，我看到了异常：

Exception in thread "main" org.quartz.impl.jdbcjobstore.LockException: Failure obtaining db row lock: Lock wait timeout exceeded; try restarting transaction [See nested exception: java.sql.SQLException: Lock wait timeout exceeded; try restarting transaction]
    at org.quartz.impl.jdbcjobstore.StdRowLockSemaphore.executeSQL(StdRowLockSemaphore.java:157)
    at org.quartz.impl.jdbcjobstore.DBSemaphore.obtainLock(DBSemaphore.java:113)
    at org.quartz.impl.jdbcjobstore.JobStoreSupport.executeInNonManagedTXLock(JobStoreSupport.java:3780)
    at org.quartz.impl.jdbcjobstore.JobStoreTX.executeInLock(JobStoreTX.java:93)
    at org.quartz.impl.jdbcjobstore.JobStoreSupport.clearAllSchedulingData(JobStoreSupport.java:1956)
    at org.quartz.core.QuartzScheduler.clear(QuartzScheduler.java:1572)
    at org.quartz.impl.StdScheduler.clear(StdScheduler.java:239)
    at com.scs.core.cron.TaskRunner.main(TaskRunner.java:52)

  20:04:15,993 DEBUG SimpleSemaphore:132 - Lock 'TRIGGER_ACCESS' retuned by: main
  20:04:15,993 DEBUG JobStoreTX:703 - JobStore background threads started (as scheduler was started).
  20:04:15,994  INFO QuartzScheduler:575 - Scheduler Test-Scheduler_$_NON_CLUSTERED started.
  20:04:15,994 DEBUG JobStoreTX:3933 - MisfireHandler: scanning for misfires...
  20:04:16,000 DEBUG JobStoreTX:3182 - Found 0 triggers that missed their scheduled fire-time.
  20:04:16,004 DEBUG QuartzSchedulerThread:276 - batch acquisition of 0 triggers
  20:04:16,008 DEBUG SimpleSemaphore:81 - Lock 'TRIGGER_ACCESS' is desired by: main
  20:04:16,008 DEBUG SimpleSemaphore:88 - Lock 'TRIGGER_ACCESS' is being obtained: main
  20:04:16,008 DEBUG SimpleSemaphore:105 - Lock 'TRIGGER_ACCESS' given to: main
        20:04:16,052 DEBUG SimpleSemaphore:132 - Lock 'TRIGGER_ACCESS' retuned by: main
        Found job: class to.test.cron.ImportProducts
        Tue Jul 15 20:05:00 CEST 2014
        isStarted=true
        isShutdown=false
        isInStandbyMode=false
        20:04:16,058 DEBUG QuartzSchedulerThread:276 - batch acquisition of 0 triggers
        20:04:42,961 ERROR ErrorLogger:2425 - An error occurred while scanning for the next triggers to fire.
        org.quartz.JobPersistenceException: Couldn't acquire next trigger: to.test.cron.ImportProducts [See nested exception: java.lang.ClassNotFoundException: to.test.cron.ImportProducts]
            at org.quartz.impl.jdbcjobstore.JobStoreSupport.acquireNextTrigger(JobStoreSupport.java:2848)
            at org.quartz.impl.jdbcjobstore.JobStoreSupport$40.execute(JobStoreSupport.java:2759)
            at org.quartz.impl.jdbcjobstore.JobStoreSupport$40.execute(JobStoreSupport.java:2757)
            at org.quartz.impl.jdbcjobstore.JobStoreSupport.executeInNonManagedTXLock(JobStoreSupport.java:3787)
            at org.quartz.impl.jdbcjobstore.JobStoreSupport.acquireNextTriggers(JobStoreSupport.java:2756)
            at org.quartz.core.QuartzSchedulerThread.run(QuartzSchedulerThread.java:272)
        Caused by: java.lang.ClassNotFoundException: to.test.cron.ImportProducts
            at java.net.URLClassLoader$1.run(Unknown Source)
            at java.net.URLClassLoader$1.run(Unknown Source)
            at java.security.AccessController.doPrivileged(Native Method)
            at java.net.URLClassLoader.findClass(Unknown Source)
            at java.lang.ClassLoader.loadClass(Unknown Source)
            at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
            at java.lang.ClassLoader.loadClass(Unknown Source)
            at org.quartz.simpl.InitThreadContextClassLoadHelper.loadClass(InitThreadContextClassLoadHelper.java:72)
            at org.quartz.simpl.CascadingClassLoadHelper.loadClass(CascadingClassLoadHelper.java:114)
            at org.quartz.simpl.CascadingClassLoadHelper.loadClass(CascadingClassLoadHelper.java:138)
            at org.quartz.impl.jdbcjobstore.StdJDBCDelegate.selectJobDetail(StdJDBCDelegate.java:852)
            at org.quartz.impl.jdbcjobstore.JobStoreSupport.acquireNextTrigger(JobStoreSupport.java:2816)
            ... 5 more

3） 在禁用集群的jdbc模式下，它也不起作用，但我得到一个异常：

Exception in thread "main" org.quartz.impl.jdbcjobstore.LockException: Failure obtaining db row lock: Lock wait timeout exceeded; try restarting transaction [See nested exception: java.sql.SQLException: Lock wait timeout exceeded; try restarting transaction]
    at org.quartz.impl.jdbcjobstore.StdRowLockSemaphore.executeSQL(StdRowLockSemaphore.java:157)
    at org.quartz.impl.jdbcjobstore.DBSemaphore.obtainLock(DBSemaphore.java:113)
    at org.quartz.impl.jdbcjobstore.JobStoreSupport.executeInNonManagedTXLock(JobStoreSupport.java:3780)
    at org.quartz.impl.jdbcjobstore.JobStoreTX.executeInLock(JobStoreTX.java:93)
    at org.quartz.impl.jdbcjobstore.JobStoreSupport.clearAllSchedulingData(JobStoreSupport.java:1956)
    at org.quartz.core.QuartzScheduler.clear(QuartzScheduler.java:1572)
    at org.quartz.impl.StdScheduler.clear(StdScheduler.java:239)
    at com.scs.core.cron.TaskRunner.main(TaskRunner.java:52)

  20:04:15,993 DEBUG SimpleSemaphore:132 - Lock 'TRIGGER_ACCESS' retuned by: main
  20:04:15,993 DEBUG JobStoreTX:703 - JobStore background threads started (as scheduler was started).
  20:04:15,994  INFO QuartzScheduler:575 - Scheduler Test-Scheduler_$_NON_CLUSTERED started.
  20:04:15,994 DEBUG JobStoreTX:3933 - MisfireHandler: scanning for misfires...
  20:04:16,000 DEBUG JobStoreTX:3182 - Found 0 triggers that missed their scheduled fire-time.
  20:04:16,004 DEBUG QuartzSchedulerThread:276 - batch acquisition of 0 triggers
  20:04:16,008 DEBUG SimpleSemaphore:81 - Lock 'TRIGGER_ACCESS' is desired by: main
  20:04:16,008 DEBUG SimpleSemaphore:88 - Lock 'TRIGGER_ACCESS' is being obtained: main
  20:04:16,008 DEBUG SimpleSemaphore:105 - Lock 'TRIGGER_ACCESS' given to: main
        20:04:16,052 DEBUG SimpleSemaphore:132 - Lock 'TRIGGER_ACCESS' retuned by: main
        Found job: class to.test.cron.ImportProducts
        Tue Jul 15 20:05:00 CEST 2014
        isStarted=true
        isShutdown=false
        isInStandbyMode=false
        20:04:16,058 DEBUG QuartzSchedulerThread:276 - batch acquisition of 0 triggers
        20:04:42,961 ERROR ErrorLogger:2425 - An error occurred while scanning for the next triggers to fire.
        org.quartz.JobPersistenceException: Couldn't acquire next trigger: to.test.cron.ImportProducts [See nested exception: java.lang.ClassNotFoundException: to.test.cron.ImportProducts]
            at org.quartz.impl.jdbcjobstore.JobStoreSupport.acquireNextTrigger(JobStoreSupport.java:2848)
            at org.quartz.impl.jdbcjobstore.JobStoreSupport$40.execute(JobStoreSupport.java:2759)
            at org.quartz.impl.jdbcjobstore.JobStoreSupport$40.execute(JobStoreSupport.java:2757)
            at org.quartz.impl.jdbcjobstore.JobStoreSupport.executeInNonManagedTXLock(JobStoreSupport.java:3787)
            at org.quartz.impl.jdbcjobstore.JobStoreSupport.acquireNextTriggers(JobStoreSupport.java:2756)
            at org.quartz.core.QuartzSchedulerThread.run(QuartzSchedulerThread.java:272)
        Caused by: java.lang.ClassNotFoundException: to.test.cron.ImportProducts
            at java.net.URLClassLoader$1.run(Unknown Source)
            at java.net.URLClassLoader$1.run(Unknown Source)
            at java.security.AccessController.doPrivileged(Native Method)
            at java.net.URLClassLoader.findClass(Unknown Source)
            at java.lang.ClassLoader.loadClass(Unknown Source)
            at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
            at java.lang.ClassLoader.loadClass(Unknown Source)
            at org.quartz.simpl.InitThreadContextClassLoadHelper.loadClass(InitThreadContextClassLoadHelper.java:72)
            at org.quartz.simpl.CascadingClassLoadHelper.loadClass(CascadingClassLoadHelper.java:114)
            at org.quartz.simpl.CascadingClassLoadHelper.loadClass(CascadingClassLoadHelper.java:138)
            at org.quartz.impl.jdbcjobstore.StdJDBCDelegate.selectJobDetail(StdJDBCDelegate.java:852)
            at org.quartz.impl.jdbcjobstore.JobStoreSupport.acquireNextTrigger(JobStoreSupport.java:2816)
            ... 5 more

我不太明白为什么我在3种不同的模式下会有3种完全不同的行为。如果这个类可以在RAM模式下找到，为什么它不能在jdbc模式下找到呢？为什么不以群集模式登录？该类实际上位于osgi类型的模块中。这会导致问题吗（在jdbc模式下）？有什么我可以做的，以便类可以找到，如传递类加载器等石英

我现在很迷路，非常感谢你的帮助。如果不得不回到标准的cron工作岗位上，那将是一种耻辱，尤其是在quartz有如此多的工作可以提供的情况下

提前感谢您提供的任何帮助

Michael

这是一个持久性工作存储的一般“问题”。您的应用程序显然试图添加作业存储中已经存在的作业，因为您的应用程序过去已经添加了该作业。您有两个选择：

在尝试添加作业/触发器之前，请在应用程序初始化期间清除作业存储区的内容。自Quartz 2.x以来，您可以使用一个新的方法Scheduler.clear（）

您可以修改应用程序代码，以处理您尝试添加的作业/触发器可能已存在于作业存储中的事实。如果存在，只需在必要时更新作业/触发器，或完全跳过作业/触发器

仔细想想，这种Quartz行为实际上是有意义的，因为作业存储中的作业/触发器可以从应用程序外部进行修改（例如，由使用Quartz remote API的外部系统进行修改）

您可能还想研究允许您将应用程序中的作业和触发器定义外部化到XML文件/资源中，并且可以处理作业/触发器名称冲突的。这提供了一个XML文件结构的示例

---

希望这能有所帮助。

谢谢你的提示。这似乎暂时停止了我的错误（提示1），并将作为一个开始。稍后我将使用#2进行改进。对于我的另一个问题，你可能有什么建议吗。当我处于RAM模式时，我的任务每分钟都在执行，但在添加quartz.properties和jdbc配置后，我可以看到正在db中创建作业，但它不再被触发。“trigger.getNextFireTime（）”也返回正确的时间。在DB中，prev_fire_time保持为-1。我将首先仔细检查调度程序是否已实际启动（即，scheduler.isStarted（）返回true）。如果这不能解决问题，那么应该在应用程序的日志配置中启用“org.quartz”类别的日志记录。如果这没有告诉您任何事情，您将不得不调试QuartzSchedulerThread以查看发生了什么。好的，看起来我需要进一步挖掘：isStarted=true，IsShutton=false，isInStandbyMode=false（3），看起来Quartz无法加载作业类。Quartz API是否由加载作业类的类加载器加载？这些错误通常发生在共享应用服务器类加载器（例如Tomcat的公共类加载器）加载Quartz API时，该类加载器在部署的应用程序（例如WEB-INF/classes、WEB-INF/lib）中没有看到绑定的作业类。Quartz在加载类（例如作业详细信息）时支持多种策略-请参阅org.Quartz.scheduler.classLoadHelper.classquartz属性。没问题。我们使用我们自己的产品做到这一点：-）请查看QuartzDesk（www.QuartzDesk.com）。即使是Lite（免费）版也允许您在常规计划之外临时执行作业。