我知道有很多关于abandoned connections的话题，但是我不知道我的情况是什么问题，所以我真的希望得到一些帮助。

我有一个带有 Spring 的 Java 应用程序，它从外部服务获取一些数据，并尝试将其保存在数据库中。

我对 JDBC 池有以下配置

<bean id="dataSource"
          class="org.apache.tomcat.jdbc.pool.DataSource"
          p:initialSize="2"
          p:minIdle="10"
          p:maxIdle="50"
          p:maxActive="100"
          p:maxWait="15000"
          p:jdbcInterceptors="org.apache.tomcat.jdbc.pool.interceptor.ConnectionState;org.apache.tomcat.jdbc.pool.interceptor.StatementFinalizer;org.apache.tomcat.jdbc.pool.interceptor.ResetAbandonedTimer"
          p:removeAbandoned="true"
          p:removeAbandonedTimeout="60"
          p:logAbandoned="true"
          p:testOnBorrow="true"
          p:testOnReturn="true"
          p:testWhileIdle="true"
          p:useEquals="false"
          p:fairQueue="false"
          p:timeBetweenEvictionRunsMillis="300000"
          p:minEvictableIdleTimeMillis="300000"
          p:validationInterval="10000"
          p:validationQuery="SELECT 1">
        <property name="driverClassName" value="${jdbc.driverClassName}"/>
        <property name="url" value="${jdbc.url}"/>
        <property name="username" value="${jdbc.user}"/>
        <property name="password" value="${jdbc.password}"/>
    </bean>

这是一个典型的 Spring 环境，在我的服务中我有以下方法

@Autowired
private TransactionalWrapper wrapper;

@Override
@Transactional(propagation = Propagation.NOT_SUPPORTED)
public void reconcileAllEvents(Date from, Date to) {
   for (Event event : eventService.reconcile(from, to)) {   
            transactionalWrapper.reconcile(event);   
   }    
}

这是我在 TransactionalWrapper

@Service
public class TransactionalWrapperImpl implements TransactionalWrapper {

        @Autowired
        private EventRepository eventRepository;

        @Transactional(propagation = Propagation.REQUIRES_NEW)
        public void reconcile(Event event) {

            try {
                eventRepository.save(event);
            } catch (Exception e) {
                LOG.warn("Failed to handle event {}", event, e);
            }
        }
    }

有一个每晚运行的作业，每次都有大约 10K 个事件。我检查过 reconcileAllEvents() 中没有 Activity 事务，并且在 TransactionalWrapperImpl.reconcile() 中为每个 event 创建并提交了新事务>.

问题是我时常遇到以下异常

Sep 10, 2015 5:25:57 PM org.apache.tomcat.jdbc.pool.ConnectionPool abandon
WARNING: Connection has been abandoned PooledConnection[org.postgresql.jdbc4.Jdbc4Connection@3eb948ed]:java.lang.Exception
    at org.apache.tomcat.jdbc.pool.ConnectionPool.getThreadDump(ConnectionPool.java:1063)
    at org.apache.tomcat.jdbc.pool.ConnectionPool.borrowConnection(ConnectionPool.java:780)
    at org.apache.tomcat.jdbc.pool.ConnectionPool.borrowConnection(ConnectionPool.java:619)
    at org.apache.tomcat.jdbc.pool.ConnectionPool.getConnection(ConnectionPool.java:188)
    at org.apache.tomcat.jdbc.pool.DataSourceProxy.getConnection(DataSourceProxy.java:128)
    at org.hibernate.ejb.connection.InjectedDataSourceConnectionProvider.getConnection(InjectedDataSourceConnectionProvider.java:70)
    at org.hibernate.internal.AbstractSessionImpl$NonContextualJdbcConnectionAccess.obtainConnection(AbstractSessionImpl.java:301)
    at org.hibernate.engine.jdbc.internal.LogicalConnectionImpl.obtainConnection(LogicalConnectionImpl.java:214)
    at org.hibernate.engine.jdbc.internal.LogicalConnectionImpl.getConnection(LogicalConnectionImpl.java:157)
    at org.hibernate.engine.transaction.internal.jdbc.JdbcTransaction.doBegin(JdbcTransaction.java:67)
    at org.hibernate.engine.transaction.spi.AbstractTransactionImpl.begin(AbstractTransactionImpl.java:160)
    at org.hibernate.internal.SessionImpl.beginTransaction(SessionImpl.java:1351)
    at org.hibernate.ejb.TransactionImpl.begin(TransactionImpl.java:59)
    at org.springframework.orm.jpa.DefaultJpaDialect.beginTransaction(DefaultJpaDialect.java:67)
    at org.springframework.orm.jpa.vendor.HibernateJpaDialect.beginTransaction(HibernateJpaDialect.java:110)
    at org.springframework.orm.jpa.JpaTransactionManager.doBegin(JpaTransactionManager.java:380)
    at org.springframework.transaction.support.AbstractPlatformTransactionManager.getTransaction(AbstractPlatformTransactionManager.java:373)
    at org.springframework.transaction.interceptor.TransactionAspectSupport.createTransactionIfNecessary(TransactionAspectSupport.java:420)
    at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:257)
    at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:95)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:644)

在这个之后还有一个

10 Sep 2015 17:25:57,591 WARN  org.hibernate.engine.jdbc.spi.SqlExceptionHelper - SQL Error: 0, SQLState: 08006
10 Sep 2015 17:25:57,592 ERROR org.hibernate.engine.jdbc.spi.SqlExceptionHelper - An I/O error occurred while sending to the backend.
javax.persistence.PersistenceException: org.hibernate.exception.JDBCConnectionException: could not extract ResultSet
    at org.hibernate.ejb.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1387)
    at org.hibernate.ejb.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1310)
    at org.hibernate.ejb.QueryImpl.getSingleResult(QueryImpl.java:316)
    at com.mysema.query.jpa.impl.AbstractJPAQuery.getSingleResult(AbstractJPAQuery.java:219)
    at com.mysema.query.jpa.impl.AbstractJPAQuery.uniqueResult(AbstractJPAQuery.java:295)
    at com.mysema.query.jpa.impl.AbstractJPAQuery.uniqueResult(AbstractJPAQuery.java:281)
    at com.mysema.query.support.ProjectableQuery.singleResult(ProjectableQuery.java:75)

我检查了几次配置，没有发现任何错误或需要批准的地方，这一直崩溃，事件没有被保存。请注意，在发生异常后，它会继续以正常方式保存其余事件。

知道配置有什么问题，以及如何处理这个问题吗？

最佳答案

这通常是在后端断开连接时由 PostgreSQL 抛出的。

1. 尝试将驱动程序更新到最新版本:9.4-1202
2. 在 postgresql.conf 中尝试设置:log_statement = 'all' ，查看所有语句日志数据，以便您更好地了解导致问题的原因。

关于java - PostgreSQL 抛出 "Connection has been abandoned"-> "An I/O error occurred while sending to the backend"，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/32507392/