重新启动quartz调度程序而不会出现错误

时间：2014-07-14 22:48:44

标签： java quartz-scheduler

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

在我开始使用集群模式的jdbc之前，我刚刚通过RAM存储测试了调度程序。这没有问题，我能够重启调度程序（主类），没有任何错误。我现在的问题是，当我停止执行（ctrl + c）然后重新启动它时，我总是收到错误消息：

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不支持重新启动调度程序吗？我的意思是，如果发生崩溃并且调度程序在恢复后重新启动会发生什么？那么从石英数据库中删除作业的唯一选择是什么？也许还有另外一种我错过的方法或东西。使用不能应对重启的库感觉不太舒服。

另一个奇怪的是，当更改为jdbc时，我的作业不再被触发，我只看到DB中的状态WAITING。这可能是什么？作业（cron-schedule）在RAM模式下没有问题。

我对文档的水平以及我遇到的这个简单任务遇到的问题感到有些惊讶，因为我已经听说过石英调度程序很多年了，但是从来没有使用它。古德尔建议我不是唯一有这个问题的人。我希望这只是我和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会非常令人失望。

这是我的配置：

#============================================================================
# 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

这是我的代码：

    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());

修改

这很有趣。

1）RAM模式有效。

2）具有集群启用功能的jdbc无法正常工作，并且（几乎）无声地失败 - 即使启用了日志记录也是如此。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

虽然，就像我要再次启用群集模式一样，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)

3）在jdbc模式下，群集已禁用它也不起作用，但我得到一个例外：

  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种不同的模式中得到3种完全不同的行为。如果可以在RAM模式下找到类，那么为什么它不能在jdbc模式下找到它？为什么它没有以群集模式登录？该类实际上是一个osgi类型的模块。这会导致问题（在jdbc模式下）吗？有什么我可以做的，所以可以找到类，就像将类加载器等传递给石英一样？

我现在很迷茫，真的很感激任何帮助。如果不得不重新回到标准的cron工作岗位，那将是一种耻辱，特别是石英有更多的东西可以提供。

提前感谢您提供的任何帮助，

迈克尔

1 个答案:

答案 0 :(得分：7)

这是持久性作业存储的一般“问题”。您的应用程序显然会尝试添加作业存储中已存在的作业，因为您的应用程序过去已添加该作业。您有两种选择：

  1. 在尝试添加作业/触发器之前，在应用程序初始化期间清除作业存储的内容。从Quartz 2.x开始，你可以使用一种新方法Scheduler.clear（）。

  2. 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。如果它存在，您只需在必要时更新作业/触发器，或完全跳过作业/触发器。

    3. 当你想到它时，这种Quartz行为实际上是有意义的，因为可以从应用程序外部修改作业存储中的作业/触发器（例如，使用Quartz远程API的外部系统）。

    您可能还想查看允许您将作业和触发器定义从应用程序外部化到XML文件/资源​​的XMLSchedulingDataProcessorPlugin，它可以处理作业/触发器名称冲突。此article提供了XML文件结构的示例。

    希望这有帮助。

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