Heroku Postgres 的 C3P0 连接池停止

Question

这与以前未解决的帖子有关：here 在 Heroku 上初始化连接池后，C3P0 似乎立即进入死锁。我的本地 postgres 上没有出现此问题。

这是来自 hibernate.hbm.xml 的连接配置

 <property name="hibernate.dialect">org.hibernate.dialect.PostgreSQLDialect</property>



    <!-- Enable Hibernate's automatic session context management -->
    <property name="current_session_context_class">thread</property>


    <property name="hibernate.connection.url">jdbc:postgresql://myurl:5432/mydb?user=myusername&amp;password=myoassword&amp;sslfactory=org.postgresql.ssl.NonValidatingFactory&amp;ssl=true</property>
    <property name="hibernate.connection.driver_class">org.postgresql.Driver</property>
    <property name="hibernate.connection.username">myusername</property>
    <property name="hibernate.connection.password">mypassword</property>
    <property name="hibernate.archive.autodetection">class</property>
    <property name="hibernate.show_sql">true</property>
    <property name="hibernate.format_sql">true</property>
    <property name="hbm2ddl.auto">create</property>

    <!-- c3p0 connection pool settings -->
    <property name="hibernate.connection.provider_class">org.hibernate.service.jdbc.connections.internal.C3P0ConnectionProvider</property>
    <property name="hibernate.c3p0.min_size">1</property>
    <property name="hibernate.c3p0.max_size">2</property>
    <property name="hibernate.c3p0.timeout">1800</property>

这是日志。请注意在“运行死锁检测器”的 10 秒循环中挂起大约一分钟。还要注意下面的调用异常：

[DEBUG]“com.mchange.v2.c3p0.impl.C3P0PooledConnectionPoolManager”2015-07-05 07:12:57,851：为身份验证创建新池，用户名（屏蔽）：'sp******' .

[DEBUG] "com.mchange.v2.resourcepool.BasicResourcePool" 2015-07-05 07:12:57,851：获取测试 -- 池大小：0；目标池大小：1；想要的目标？ 1

...为简洁起见删除了一些行

[DEBUG] "com.mchange.v2.resourcepool.BasicResourcePool" 2015-07-05 07:12:59,132：采集系列成功终止。减少pending_acquires 1，尝试剩余：30

[DEBUG]“com.mchange.v2.resourcepool.BasicResourcePool”2015-07-05 07:12:59,132：跟踪 com.mchange.v2.resourcepool.BasicResourcePool@6293abcc [托管：2，未使用：1，排除: 0] (例如 com.mchange.v2.c3p0.impl.NewPooledConnection@576ddf03)

[DEBUG] "com.mchange.v2.resourcepool.BasicResourcePool" 2015-07-05 07:12:59,132: 递减的pending_acquires: 0

[DEBUG] "com.mchange.v2.resourcepool.BasicResourcePool" 2015-07-05 07:12:59,132：采集系列成功终止。递减pending_acquires [0]，attempts_remaining：30

[DEBUG]“com.mchange.v2.resourcepool.BasicResourcePool”2015-07-05 07:12:59,132：跟踪 com.mchange.v2.resourcepool.BasicResourcePool@6293abcc [托管：2，未使用：1，排除: 0] (例如 com.mchange.v2.c3p0.impl.NewPooledConnection@576ddf03)

[DEBUG] "com.mchange.v2.async.ThreadPoolAsynchronousRunner" 2015-07-05 07:13:07,841: com.mchange.v2.async.ThreadPoolAsynchronousRunner$DeadlockDetector@45912fb9 -- 运行死锁检测器[退出。没有待处理的任务。]

...每十秒重复一次

[DEBUG]“com.mchange.v2.async.ThreadPoolAsynchronousRunner”2015-07-05 07:13:47,859：com.mchange.v2.async.ThreadPoolAsynchronousRunner$DeadlockDetector@45912fb9——运行死锁检测器[退出。没有待处理的任务。]

[INFO] "org.hibernate.dialect.Dialect" 2015-07-05 07:13:55,467: HHH000400: 使用方言：org.hibernate.dialect.PostgreSQLDialect

[INFO]“org.hibernate.engine.jdbc.internal.LobCreatorBuilder”2015-07-05 07:13:55,472：HHH000424：禁用上下文 LOB 创建作为 createClob() 方法引发错误：java.lang.reflect。调用目标异常

[DEBUG] "com.mchange.v2.async.ThreadPoolAsynchronousRunner" 2015-07-05 07:13:55,576: com.mchange.v2.async.ThreadPoolAsynchronousRunner@6a01e23: 将任务添加到队列——com.mchange。 v2.resourcepool.BasicResourcePool$1RefurbishCheckinResourceTask@55b699ef

Answer 1

答案其实已经贴出来了，解释的很好here：

我在 hibernate.hbm.xml 中添加了以下内容

<property name="temp.use_jdbc_metadata_defaults">false</property>