Wildfly 8.0.0.Final + EntityManager + PostgreSQL - 在事务中空闲

Question

我在 Wildfly 8.0.0.Final 上运行了以下代码：

@Stateful
public class MyJPABean<T> {

    @PersistenceContext(unitName = "myUnitName")
    private EntityManager em;

    @TransactionAttribute(TransactionAttributeType.REQUIRED)
    public void write(T entity) {
        em.persist(entity);
        em.flush();
    }

    @TransactionAttribute(TransactionAttributeType.REQUIRED)
    public void update(T entity) {
        em.merge(entity);
    }
}

write 和 update 方法都是并行调用的，因为它们是直接从另一个处理 HTTP 请求的类调用的：

@Path("api")
public class MyApiController {

    private MyJPABean<MyJpaModel> jpaBean;

    @POST
    @Consumes(MediaType.APPLICATION_JSON)
    @Produces(MediaType.APPLICATION_JSON)
    public void handlePost(MyJpaModel myJpaModel) {
       jpaBean.write(myJpaModel);
    }
}

有些“write”方法调用成功，但时不时地，当“write”方法被多个线程并行调用时，它开始挂在em.persist(entity)上。

在 PostgreSQL 服务器端，我可以看到事务处于状态：“idle in transaction”，查询：“select nextval ('hibernate_sequence')”或插入从我刚刚尝试持久化的实体创建的查询。

当这个问题发生时，我不能再持久化实体了。一切都挂在 em.persist(entity) 上。要么我无法杀死wildfly进程，我必须用-9信号杀死它。

是不是我做错了什么？

一段时间后（发生超时），我可以在应用程序日志中看到以下警告：

16:44:30,590 WARN  [com.arjuna.ats.arjuna] (Transaction Reaper) ARJUNA012117: TransactionReaper::check timeout for TX 0:ffff7f000101:-231d9b5d:55030494:2d in state  RUN
16:44:30,591 WARN  [com.arjuna.ats.arjuna] (Transaction Reaper Worker 0) ARJUNA012095: Abort of action id 0:ffff7f000101:-231d9b5d:55030494:2d invoked while multiple threads active within it.
16:44:30,591 WARN  [com.arjuna.ats.arjuna] (Transaction Reaper Worker 0) ARJUNA012108: CheckedAction::check - atomic action 0:ffff7f000101:-231d9b5d:55030494:2d aborting with 1 threads active!
16:44:30,598 WARN  [com.arjuna.ats.arjuna] (Transaction Reaper) ARJUNA012117: TransactionReaper::check timeout for TX 0:ffff7f000101:-231d9b5d:55030494:35 in state  RUN
16:44:31,090 WARN  [com.arjuna.ats.arjuna] (Transaction Reaper) ARJUNA012117: TransactionReaper::check timeout for TX 0:ffff7f000101:-231d9b5d:55030494:2d in state  CANCEL
16:44:31,092 WARN  [com.arjuna.ats.arjuna] (Transaction Reaper) ARJUNA012378: ReaperElement appears to be wedged: com.arjuna.ats.arjuna.coordinator.TwoPhaseCoordinator.afterCompletion(TwoPhaseCoordinator.java:487)
com.arjuna.ats.arjuna.coordinator.TwoPhaseCoordinator.afterCompletion(TwoPhaseCoordinator.java:463)
com.arjuna.ats.arjuna.coordinator.TwoPhaseCoordinator.cancel(TwoPhaseCoordinator.java:118)
com.arjuna.ats.arjuna.AtomicAction.cancel(AtomicAction.java:215)
com.arjuna.ats.arjuna.coordinator.TransactionReaper.doCancellations(TransactionReaper.java:377)
com.arjuna.ats.internal.arjuna.coordinator.ReaperWorkerThread.run(ReaperWorkerThread.java:78)

16:44:31,100 WARN  [com.arjuna.ats.arjuna] (Transaction Reaper) ARJUNA012117: TransactionReaper::check timeout for TX 0:ffff7f000101:-231d9b5d:55030494:35 in state  SCHEDULE_CANCEL
16:44:31,594 WARN  [com.arjuna.ats.arjuna] (Transaction Reaper) ARJUNA012117: TransactionReaper::check timeout for TX 0:ffff7f000101:-231d9b5d:55030494:2d in state  CANCEL_INTERRUPTED
16:44:31,595 WARN  [com.arjuna.ats.arjuna] (Transaction Reaper) ARJUNA012120: TransactionReaper::check worker Thread[Transaction Reaper Worker 0,5,main] not responding to interrupt when cancelling TX 0:ffff7f000101:-231d9b5d:55030494:2d -- worker marked as zombie and TX scheduled for mark-as-rollback
16:44:31,596 WARN  [com.arjuna.ats.arjuna] (Transaction Reaper Worker 1) ARJUNA012095: Abort of action id 0:ffff7f000101:-231d9b5d:55030494:35 invoked while multiple threads active within it.
16:44:31,597 WARN  [com.arjuna.ats.arjuna] (Transaction Reaper) ARJUNA012110: TransactionReaper::check successfuly marked TX 0:ffff7f000101:-231d9b5d:55030494:2d as rollback only
16:44:31,597 WARN  [com.arjuna.ats.arjuna] (Transaction Reaper Worker 1) ARJUNA012108: CheckedAction::check - atomic action 0:ffff7f000101:-231d9b5d:55030494:35 aborting with 1 threads active!
16:44:31,600 WARN  [com.arjuna.ats.arjuna] (Transaction Reaper) ARJUNA012117: TransactionReaper::check timeout for TX 0:ffff7f000101:-231d9b5d:55030494:35 in state  CANCEL
16:44:31,602 WARN  [com.arjuna.ats.arjuna] (Transaction Reaper) ARJUNA012378: ReaperElement appears to be wedged: org.apache.log4j.AppenderSkeleton.doAppend(AppenderSkeleton.java:231)

作为 jdbc 驱动程序，使用“postgresql-9.2-1004.jdbc41”。 PostgreSQL 服务器版本是“9.3”。我在类路径上也有 c3p0，但即使我删除了这个依赖项，问题还是出现了。

Answer 1

我已经使用 JAX-RS、EJB 和 JPA 准备了一个示例应用程序 - https://github.com/aparnachaudhary/prototypes/tree/master/jaxrs-db-access。 我使用 JMeter 脚本通过多个线程访问 REST 端点。但我无法重现 PostgreSQL 9.3、postgresql-9.3-1103.jdbc41.jar 和 WildFly 8.1.0.Final 的问题。