Hibernate/HikariCP连接泄漏：关闭会话后连接仍活跃

问题背景 #

基于Tomcat9部署的对外数据库读写API应用，使用Hibernate与HikariCP时，在半复杂业务流程中出现StatelessSession导致的连接泄漏问题。

会话管理实现 #

会话获取方式 #

每次通过openSession()获取StatelessSession：

public static SessionFactory getSessionFactory()
{
    if (sessionFactory == null)
    {
        sessionFactory = buildSessionFactory();
    }

    return sessionFactory;
}

public static StatelessSession openSession()
{
    return getSessionFactory().openStatelessSession();
}

会话错误处理与关闭逻辑 #

异常处理时调用resolveError(session)，会话结束时调用closeSession(session)：

public static void resolveError(StatelessSession session)
{
    if (session != null
            && session.getTransaction() != null
            && session.getTransaction().getStatus() != null
            && session.getTransaction().getStatus() == TransactionStatus.ACTIVE)
    {
        session.getTransaction().rollback();
    }

}

public static void closeSession(StatelessSession session)
{
    if (session != null)
    {
        if (session.getTransaction() != null
                && session.getTransaction().getStatus() != null
                && session.getTransaction().getStatus() == TransactionStatus.ACTIVE)
        {
            session.getTransaction().commit();
        }

        session.close();
        session = null;
    }
}

连接泄漏排查 #

Hikari连接池监控实现 #

通过JMX获取Hikari连接池的监控Bean：

public static HikariPoolMXBean getHikariPool()
{
    try
    {
        MBeanServer bean = ManagementFactory.getPlatformMBeanServer();
        ObjectName poolName = new ObjectName("com.zaxxer.hikari:type=Pool (HikariPool-1)");

        return JMX.newMXBeanProxy(bean, poolName, HikariPoolMXBean.class);
    }
    catch (MalformedObjectNameException e)
    {
        e.printStackTrace();
    }

    return null;
}

监控状态对比 #

• 服务刚启动时状态：

[02-07-2024 17:06:16,640][DEBUG][] ================================================
[02-07-2024 17:06:16,640][DEBUG][] Idle Connections:   10
[02-07-2024 17:06:16,640][DEBUG][] Active Connections: 0
[02-07-2024 17:06:16,640][DEBUG][] Thread Awaiting:    0
[02-07-2024 17:06:16,640][DEBUG][] Total Connections:  10
[02-07-2024 17:06:16,640][DEBUG][] ================================================

• 涉事方法执行后数分钟状态：

[02-07-2024 17:06:16,640][DEBUG][] ================================================
[02-07-2024 17:06:16,640][DEBUG][] Idle Connections:   10
[02-07-2024 17:06:16,640][DEBUG][] Active Connections: 1
[02-07-2024 17:06:16,640][DEBUG][] Thread Awaiting:    0
[02-07-2024 17:06:16,640][DEBUG][] Total Connections:  11
[02-07-2024 17:06:16,640][DEBUG][] ================================================

涉事方法的会话操作逻辑 #

整理后的业务方法中会话相关代码：

private static final Object lock = new Object();

public Response method(DTO dto)
{
    StatelessSession session = openSession();
    
    ...

    try
    {
        validateDTO(dto); // hibernate-validator

        ...

        closeSession(session);

        synchronized (lock)
        {
            session = openSession();
            session.getTransaction().begin();

            ...

            session.getTransaction().commit();

            ...         

            closeSession(session);

            return Response.status(Response.Status.OK)
                    .entity(...).build();
        }
    }
    catch (Exception e)
    {
        ...

        resolveError(session);
        closeSession(session);

        return Response.status(Response.Status.INTERNAL_SERVER_ERROR)
                .entity(...).build();
    }
}

问题咨询 #

上述会话管理步骤是否存在错误？是否需要更换会话关闭方式？

内容的提问来源于stack exchange，提问作者G. Ciardini