Jdbc 尝试在后台线程中获取缓存的PreparedStatement时出错

我们在数据库组件中使用mule提供的连接池。当我们应用了巨大的负载时，我们得到了低于错误的结果

将参数配置为：maxConnection=100、minConn=0、autoIncrement=15 waitMillisec=10000，而prepared语句缓存大小将其保留为默认值（即未配置任何内容）。 你能帮我把这件事告诉我吗

{"timestamp":"2016-10-22T09:28:13,611","level":"WARN","thread":"ActiveMQ Session Task-25","loggerName":"com.mchange.v2.c3p0.impl.NewPooledConnection","message":"[c3p0] A PooledConnection that has already signalled a Connection error is still in use!"}    
{"timestamp":"2016-10-22T09:28:13,611","level":"WARN","thread":"ActiveMQ Session Task-25","loggerName":"com.mchange.v2.c3p0.impl.NewPooledConnection","message":"[c3p0] Another error has occurred [ java.sql.SQLException: A problem occurred while trying to acquire a cached PreparedStatement in a background thread. ] which will not be reported to listeners!"}
    java.sql.SQLException: A problem occurred while trying to acquire a cached PreparedStatement in a background thread.
        at com.mchange.v2.c3p0.stmt.GooGooStatementCache.acquireStatement(GooGooStatementCache.java:571) ~[?:?]
        at com.mchange.v2.c3p0.stmt.GooGooStatementCache.checkoutStatement(GooGooStatementCache.java:204) ~[?:?]
        at com.mchange.v2.c3p0.impl.NewPooledConnection.checkoutStatement(NewPooledConnection.java:321) ~[?:?]
        at com.mchange.v2.c3p0.impl.NewProxyConnection.prepareStatement(NewProxyConnection.java:455) ~[?:?]
        at org.mule.module.db.internal.domain.connection.DefaultDbConnection.prepareStatement(DefaultDbConnection.java:52) ~[?:?]
        at org.mule.module.db.internal.domain.autogeneratedkey.NoAutoGeneratedKeyStrategy.prepareStatement(NoAutoGeneratedKeyStrategy.java:34) ~[?:?]
        at org.mule.module.db.internal.domain.statement.QueryStatementFactory.create(QueryStatementFactory.java:59) ~[?:?]
        at org.mule.module.db.internal.domain.executor.AbstractSingleQueryExecutor.execute(AbstractSingleQueryExecutor.java:44) ~[?:?]
        at org.mule.module.db.internal.processor.UpdateMessageProcessor.doExecuteQuery(UpdateMessageProcessor.java:59) ~[?:?]
        at org.mule.module.db.internal.processor.AbstractSingleQueryDbMessageProcessor.executeQuery(AbstractSingleQueryDbMessageProcessor.java:42) ~[?:?]
        at org.mule.module.db.internal.processor.AbstractDbMessageProcessor.process(AbstractDbMessageProcessor.java:66) ~[?:?]
        at org.mule.execution.ExceptionToMessagingExceptionExecutionInterceptor.execute(ExceptionToMessagingExceptionExecutionInterceptor.java:24) ~[?:?]
        at org.mule.execution.MessageProcessorNotificationExecutionInterceptor.execute(MessageProcessorNotificationExecutionInterceptor.java:107) ~[?:?]
        at org.mule.execution.MessageProcessorExecutionTemplate.execute(MessageProcessorExecutionTemplate.java:44) ~[?:?]
        at org.mule.processor.BlockingProcessorExecutor.executeNext(BlockingProcessorExecutor.java:88) ~[?:?]
        at org.mule.processor.BlockingProcessorExecutor.execute(BlockingProcessorExecutor.java:59) ~[?:?]
        at org.mule.processor.chain.DefaultMessageProcessorChain.doProcess(DefaultMessageProcessorChain.java:80) ~[?:?]
        at org.mule.processor.chain.AbstractMessageProcessorChain.process(AbstractMessageProcessorChain.java:76) ~[?:?]
        at org.mule.processor.chain.InterceptingChainLifecycleWrapper.doProcess(InterceptingChainLifecycleWrapper.java:50) ~[?:?]
        at org.mule.processor.chain.AbstractMessageProcessorChain.process(AbstractMessageProcessorChain.java:76) ~[?:?]
        at org.mule.processor.chain.InterceptingChainLifecycleWrapper.access$001(InterceptingChainLifecycleWrapper.java:22) ~[?:?]
        at org.mule.processor.chain.InterceptingChainLifecycleWrapper$1.process(InterceptingChainLifecycleWrapper.java:66) ~[?:?]
        at org.mule.execution.ExceptionToMessagingExceptionExecutionInterceptor.execute(ExceptionToMessagingExceptionExecutionInterceptor.java:24) ~[?:?]
        at org.mule.execution.MessageProcessorNotificationExecutionInterceptor.execute(MessageProcessorNotificationExecutionInterceptor.java:107) ~[?:?]
        at org.mule.execution.MessageProcessorExecutionTemplate.execute(MessageProcessorExecutionTemplate.java:44) ~[?:?]
        at org.mule.processor.chain.InterceptingChainLifecycleWrapper.process(InterceptingChainLifecycleWrapper.java:61) ~[?:?]
        at org.mule.execution.ExceptionToMessagingExceptionExecutionInterceptor.execute(ExceptionToMessagingExceptionExecutionInterceptor.java:24) ~[?:?]
        at org.mule.execution.MessageProcessorNotificationExecutionInterceptor.execute(MessageProcessorNotificationExecutionInterceptor.java:107) ~[?:?]
        at org.mule.execution.MessageProcessorExecutionTemplate.execute(MessageProcessorExecutionTemplate.java:44) ~[?:?]
        at org.mule.processor.BlockingProcessorExecutor.executeNext(BlockingProcessorExecutor.java:88) ~[?:?]
        at org.mule.processor.BlockingProcessorExecutor.execute(BlockingProcessorExecutor.java:59) ~[?:?]
        at org.mule.processor.chain.DefaultMessageProcessorChain.doProcess(DefaultMessageProcessorChain.java:80) ~[?:?]
        at org.mule.processor.chain.AbstractMessageProcessorChain.process(AbstractMessageProcessorChain.java:76) ~[?:?]
        at org.mule.execution.ExceptionToMessagingExceptionExecutionInterceptor.execute(ExceptionToMessagingExceptionExecutionInterceptor.java:24) ~[?:?]
        at org.mule.execution.MessageProcessorExecutionTemplate.execute(MessageProcessorExecutionTemplate.java:44) ~[?:?]
        at org.mule.processor.BlockingProcessorExecutor.executeNext(BlockingProcessorExecutor.java:98) ~[?:?]
        at org.mule.processor.BlockingProcessorExecutor.execute(BlockingProcessorExecutor.java:59) ~[?:?]
        at org.mule.processor.AbstractInterceptingMessageProcessorBase.processNext(AbstractInterceptingMessageProcessorBase.java:98) ~[?:?]
        at org.mule.construct.DynamicPipelineMessageProcessor.process(DynamicPipelineMessageProcessor.java:55) ~[?:?]
        at org.mule.execution.ExceptionToMessagingExceptionExecutionInterceptor.execute(ExceptionToMessagingExceptionExecutionInterceptor.java:24) ~[?:?]
        at org.mule.execution.MessageProcessorNotificationExecutionInterceptor.execute(MessageProcessorNotificationExecutionInterceptor.java:107) ~[?:?]
        at org.mule.execution.MessageProcessorExecutionTemplate.execute(MessageProcessorExecutionTemplate.java:44) ~[?:?]
        at org.mule.processor.BlockingProcessorExecutor.executeNext(BlockingProcessorExecutor.java:88) ~[?:?]
        at org.mule.processor.BlockingProcessorExecutor.execute(BlockingProcessorExecutor.java:59) ~[?:?]
        at org.mule.processor.chain.DefaultMessageProcessorChain.doProcess(DefaultMessageProcessorChain.java:80) ~[?:?]
        at org.mule.processor.chain.AbstractMessageProcessorChain.process(AbstractMessageProcessorChain.java:76) ~[?:?]
        at org.mule.execution.ExceptionToMessagingExceptionExecutionInterceptor.execute(ExceptionToMessagingExceptionExecutionInterceptor.java:24) ~[?:?]
        at org.mule.execution.MessageProcessorExecutionTemplate.execute(MessageProcessorExecutionTemplate.java:44) ~[?:?]
        at org.mule.processor.BlockingProcessorExecutor.executeNext(BlockingProcessorExecutor.java:98) ~[?:?]
        at org.mule.processor.BlockingProcessorExecutor.execute(BlockingProcessorExecutor.java:59) ~[?:?]
        at org.mule.processor.AbstractInterceptingMessageProcessorBase.processNext(AbstractInterceptingMessageProcessorBase.java:98) ~[?:?]
        at org.mule.interceptor.AbstractEnvelopeInterceptor.processBlocking(AbstractEnvelopeInterceptor.java:58) ~[?:?]
        at org.mule.processor.AbstractRequestResponseMessageProcessor.process(AbstractRequestResponseMessageProcessor.java:47) ~[?:?]
        at org.mule.execution.ExceptionToMessagingExceptionExecutionInterceptor.execute(ExceptionToMessagingExceptionExecutionInterceptor.java:24) ~[?:?]
        at org.mule.execution.MessageProcessorNotificationExecutionInterceptor.execute(MessageProcessorNotificationExecutionInterceptor.java:107) ~[?:?]
        at org.mule.execution.MessageProcessorExecutionTemplate.execute(MessageProcessorExecutionTemplate.java:44) ~[?:?]
        at org.mule.processor.BlockingProcessorExecutor.executeNext(BlockingProcessorExecutor.java:98) ~[?:?]
        at org.mule.processor.BlockingProcessorExecutor.execute(BlockingProcessorExecutor.java:59) ~[?:?]
        at org.mule.processor.AbstractInterceptingMessageProcessorBase.processNext(AbstractInterceptingMessageProcessorBase.java:98) ~[?:?]
        at org.mule.processor.AbstractFilteringMessageProcessor.process(AbstractFilteringMessageProcessor.java:41) ~[?:?]
        at org.mule.execution.ExceptionToMessagingExceptionExecutionInterceptor.execute(ExceptionToMessagingExceptionExecutionInterceptor.java:24) ~[?:?]
        at org.mule.execution.MessageProcessorNotificationExecutionInterceptor.execute(MessageProcessorNotificationExecutionInterceptor.java:107) ~[?:?]
        at org.mule.execution.MessageProcessorExecutionTemplate.execute(MessageProcessorExecutionTemplate.java:44) ~[?:?]
        at org.mule.processor.BlockingProcessorExecutor.executeNext(BlockingProcessorExecutor.java:98) ~[?:?]
        at org.mule.processor.BlockingProcessorExecutor.execute(BlockingProcessorExecutor.java:59) ~[?:?]
        at org.mule.processor.AbstractInterceptingMessageProcessorBase.processNext(AbstractInterceptingMessageProcessorBase.java:98) ~[?:?]
        at org.mule.processor.AbstractRequestResponseMessageProcessor.processBlocking(AbstractRequestResponseMessageProcessor.java:56) ~[?:?]
        at org.mule.processor.AbstractRequestResponseMessageProcessor.process(AbstractRequestResponseMessageProcessor.java:47) ~[?:?]
        at org.mule.execution.ExceptionToMessagingExceptionExecutionInterceptor.execute(ExceptionToMessagingExceptionExecutionInterceptor.java:24) ~[?:?]
        at org.mule.execution.MessageProcessorNotificationExecutionInterceptor.execute(MessageProcessorNotificationExecutionInterceptor.java:107) ~[?:?]
        at org.mule.execution.MessageProcessorExecutionTemplate.execute(MessageProcessorExecutionTemplate.java:44) ~[?:?]
        at org.mule.processor.BlockingProcessorExecutor.executeNext(BlockingProcessorExecutor.java:88) ~[?:?]
        at org.mule.processor.BlockingProcessorExecutor.execute(BlockingProcessorExecutor.java:59) ~[?:?]
        at org.mule.processor.chain.DefaultMessageProcessorChain.doProcess(DefaultMessageProcessorChain.java:80) ~[?:?]
        at org.mule.processor.chain.AbstractMessageProcessorChain.process(AbstractMessageProcessorChain.java:76) ~[?:?]
        at org.mule.processor.chain.InterceptingChainLifecycleWrapper.doProcess(InterceptingChainLifecycleWrapper.java:50) ~[?:?]
        at org.mule.processor.chain.AbstractMessageProcessorChain.process(AbstractMessageProcessorChain.java:76) ~[?:?]
        at org.mule.processor.chain.InterceptingChainLifecycleWrapper.access$001(InterceptingChainLifecycleWrapper.java:22) ~[?:?]
        at org.mule.processor.chain.InterceptingChainLifecycleWrapper$1.process(InterceptingChainLifecycleWrapper.java:66) ~[?:?]
        at org.mule.execution.ExceptionToMessagingExceptionExecutionInterceptor.execute(ExceptionToMessagingExceptionExecutionInterceptor.java:24) ~[?:?]
        at org.mule.execution.MessageProcessorNotificationExecutionInterceptor.execute(MessageProcessorNotificationExecutionInterceptor.java:107) ~[?:?]
        at org.mule.execution.MessageProcessorExecutionTemplate.execute(MessageProcessorExecutionTemplate.java:44) ~[?:?]
        at org.mule.processor.chain.InterceptingChainLifecycleWrapper.process(InterceptingChainLifecycleWrapper.java:61) ~[?:?]
        at org.mule.construct.AbstractPipeline$3.process(AbstractPipeline.java:231) ~[?:?]
        at org.mule.execution.ExceptionToMessagingExceptionExecutionInterceptor.execute(ExceptionToMessagingExceptionExecutionInterceptor.java:24) ~[?:?]
        at org.mule.execution.MessageProcessorNotificationExecutionInterceptor.execute(MessageProcessorNotificationExecutionInterceptor.java:107) ~[?:?]
        at org.mule.execution.MessageProcessorExecutionTemplate.execute(MessageProcessorExecutionTemplate.java:44) ~[?:?]
        at org.mule.processor.chain.SimpleMessageProcessorChain.doProcess(SimpleMessageProcessorChain.java:43) ~[?:?]
        at org.mule.processor.chain.AbstractMessageProcessorChain.process(AbstractMessageProcessorChain.java:76) ~[?:?]
        at org.mule.processor.chain.InterceptingChainLifecycleWrapper.doProcess(InterceptingChainLifecycleWrapper.java:50) ~[?:?]
        at org.mule.processor.chain.AbstractMessageProcessorChain.process(AbstractMessageProcessorChain.java:76) ~[?:?]
        at org.mule.processor.chain.InterceptingChainLifecycleWrapper.access$001(InterceptingChainLifecycleWrapper.java:22) ~[?:?]
        at org.mule.processor.chain.InterceptingChainLifecycleWrapper$1.process(InterceptingChainLifecycleWrapper.java:66) ~[?:?]
        at org.mule.execution.ExceptionToMessagingExceptionExecutionInterceptor.execute(ExceptionToMessagingExceptionExecutionInterceptor.java:24) ~[?:?]
        at org.mule.execution.MessageProcessorNotificationExecutionInterceptor.execute(MessageProcessorNotificationExecutionInterceptor.java:107) ~[?:?]
        at org.mule.execution.MessageProcessorExecutionTemplate.execute(MessageProcessorExecutionTemplate.java:44) ~[?:?]
        at org.mule.processor.chain.InterceptingChainLifecycleWrapper.process(InterceptingChainLifecycleWrapper.java:61) ~[?:?]
        at org.mule.transport.AbstractMessageReceiver.routeEvent(AbstractMessageReceiver.java:511) ~[?:?]
        at org.mule.transport.AbstractMessageReceiver.routeMessage(AbstractMessageReceiver.java:226) ~[?:?]
        at org.mule.transport.AbstractMessageReceiver.routeMessage(AbstractMessageReceiver.java:208) ~[?:?]
        at org.mule.transport.AbstractReceiverWorker$1$1.process(AbstractReceiverWorker.java:145) ~[?:?]
        at org.mule.transport.AbstractReceiverWorker$1$1.process(AbstractReceiverWorker.java:113) ~[?:?]
        at org.mule.execution.ExecuteCallbackInterceptor.execute(ExecuteCallbackInterceptor.java:16) ~[?:?]
        at org.mule.execution.CommitTransactionInterceptor.execute(CommitTransactionInterceptor.java:35) ~[?:?]
        at org.mule.execution.CommitTransactionInterceptor.execute(CommitTransactionInterceptor.java:22) ~[?:?]
        at org.mule.execution.HandleExceptionInterceptor.execute(HandleExceptionInterceptor.java:30) ~[?:?]
        at org.mule.execution.HandleExceptionInterceptor.execute(HandleExceptionInterceptor.java:14) ~[?:?]
        at org.mule.execution.BeginAndResolveTransactionInterceptor.execute(BeginAndResolveTransactionInterceptor.java:67) ~[?:?]
        at org.mule.execution.ResolvePreviousTransactionInterceptor.execute(ResolvePreviousTransactionInterceptor.java:44) ~[?:?]
        at org.mule.execution.SuspendXaTransactionInterceptor.execute(SuspendXaTransactionInterceptor.java:50) ~[?:?]
        at org.mule.execution.ValidateTransactionalStateInterceptor.execute(ValidateTransactionalStateInterceptor.java:40) ~[?:?]
        at org.mule.execution.IsolateCurrentTransactionInterceptor.execute(IsolateCurrentTransactionInterceptor.java:41) ~[?:?]
        at org.mule.execution.ExternalTransactionInterceptor.execute(ExternalTransactionInterceptor.java:48) ~[?:?]
        at org.mule.execution.RethrowExceptionInterceptor.execute(RethrowExceptionInterceptor.java:28) ~[?:?]
        at org.mule.execution.RethrowExceptionInterceptor.execute(RethrowExceptionInterceptor.java:13) ~[?:?]
        at org.mule.execution.TransactionalErrorHandlingExecutionTemplate.execute(TransactionalErrorHandlingExecutionTemplate.java:110) ~[?:?]
        at org.mule.execution.TransactionalErrorHandlingExecutionTemplate.execute(TransactionalErrorHandlingExecutionTemplate.java:30) ~[?:?]
        at org.mule.transport.AbstractReceiverWorker$1.process(AbstractReceiverWorker.java:112) ~[?:?]
        at org.mule.transport.AbstractReceiverWorker$1.process(AbstractReceiverWorker.java:96) ~[?:?]
        at org.mule.execution.ExecuteCallbackInterceptor.execute(ExecuteCallbackInterceptor.java:16) ~[?:?]
        at org.mule.execution.BeginAndResolveTransactionInterceptor.execute(BeginAndResolveTransactionInterceptor.java:67) ~[?:?]
        at org.mule.execution.ResolvePreviousTransactionInterceptor.execute(ResolvePreviousTransactionInterceptor.java:44) ~[?:?]
        at org.mule.execution.SuspendXaTransactionInterceptor.execute(SuspendXaTransactionInterceptor.java:50) ~[?:?]
        at org.mule.execution.ValidateTransactionalStateInterceptor.execute(ValidateTransactionalStateInterceptor.java:40) ~[?:?]
        at org.mule.execution.IsolateCurrentTransactionInterceptor.execute(IsolateCurrentTransactionInterceptor.java:41) ~[?:?]
        at org.mule.execution.ExternalTransactionInterceptor.execute(ExternalTransactionInterceptor.java:48) ~[?:?]
        at org.mule.execution.TransactionalExecutionTemplate.execute(TransactionalExecutionTemplate.java:65) ~[?:?]
        at org.mule.transport.AbstractReceiverWorker.processMessages(AbstractReceiverWorker.java:179) ~[?:?]
        at org.mule.transport.jms.MultiConsumerJmsMessageReceiver$SubReceiver.onMessage(MultiConsumerJmsMessageReceiver.java:439) ~[?:?]
        at org.apache.activemq.ActiveMQMessageConsumer.dispatch(ActiveMQMessageConsumer.java:1394) ~[?:?]
        at org.apache.activemq.ActiveMQSessionExecutor.dispatch(ActiveMQSessionExecutor.java:131) ~[?:?]
        at org.apache.activemq.ActiveMQSessionExecutor.iterate(ActiveMQSessionExecutor.java:202) ~[?:?]
        at org.apache.activemq.thread.PooledTaskRunner.runTask(PooledTaskRunner.java:133) ~[?:?]
        at org.apache.activemq.thread.PooledTaskRunner$1.run(PooledTaskRunner.java:48) ~[?:?]
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [?:1.8.0_73]
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [?:1.8.0_73]
        at java.lang.Thread.run(Thread.java:745) [?:1.8.0_73]
    Caused by: com.microsoft.sqlserver.jdbc.SQLServerException: The connection is closed.
        at com.microsoft.sqlserver.jdbc.SQLServerException.makeFromDriverError(SQLServerException.java:170) ~[?:?]
        at com.microsoft.sqlserver.jdbc.SQLServerConnection.checkClosed(SQLServerConnection.java:304) ~[?:?]
        at com.microsoft.sqlserver.jdbc.SQLServerConnection.prepareStatement(SQLServerConnection.java:1863) ~[?:?]
        at com.microsoft.sqlserver.jdbc.SQLServerConnection.prepareStatement(SQLServerConnection.java:1566) ~[?:?]
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_73]
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_73]
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_73]
        at java.lang.reflect.Method.invoke(Method.java:497) ~[?:1.8.0_73]
        at com.mchange.v2.c3p0.stmt.GooGooStatementCache$1StmtAcquireTask.run(GooGooStatementCache.java:546) ~[?:?]
        at com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:696) ~[?:?]

嗯

如果您使用的是语句缓存，那么如果连接没有合适的缓存语句可用，c3p0将异步获取缓存语句。在高负载和未仔细配置的情况下，由于服务器拥塞或c3p0线程池拥塞，此异步获取可能需要很长时间。试图获取语句的客户端将无限期地等待，直到成功获取该语句或发生异常为止

从根本原因异常（一直向下到堆栈跟踪的底部）可以清楚地看到，当潜在的长语句获取发生时，从中获取语句的连接被关闭或终止。这就是你需要调试才能真正理解这一点。可能的原因包括：

在这种情况下，负载/网络问题/神秘的小精灵偶尔会破坏连接，导致连接无效并关闭（）

DBMS或某些管理监视程序close（）会关闭这些（可能是长时间挂起的）连接，因为打开的连接太多或打开的时间太长。（这可能是死锁检测器的工作。）

您的应用程序（不明智地）在多个线程中使用连接，其中一个线程调用close（），而另一个线程仍在等待（）语句。然后，池（出于多种原因之一）尝试关闭（）导致此错误的签入连接

如果（3）是这样，你应该停止这样做，但我认为这是最不可能的情况。如果是（1）或（2），那么缓解问题的主要方法是确保语句获取速度快，这样在等待语句时就不太可能发生不好的事情

我要看的第一件事是c3p0的线程池在您的应用程序所处的负载条件下。它还在继续吗？（您可以通过JMX或对PooledDataSource方法（如或）的调用来检查这一点，最简单的方法是简单地放大c3p0配置参数，因此语句获取之类的任务不太可能积压

另一个真正有帮助的配置更改是确保允许足够数量的缓存语句来防止搅动（不断关闭（）并重新获取语句缓存中的连接）。一个非常常见的配置错误是将全局配置参数设置为太低的值。要正确设置，最简单的方法是使用，而不是全局限制，并将其设置为应用程序经常使用的PreparedStatements的数量

要真正了解发生了什么，您需要查看哪些类型的任务被积压。再次直接在代码中或通过JMX使用

更新：在原始帖子中，您声明“准备语句缓存大小将其保留为默认值”。这可能是mule的默认设置，但c3p0的默认设置是根本不使用语句缓存，

maxStatements=0

和

maxStatementsPerConnection=0

。您的配置可能与您想象的不同。禁用语句缓存可能是解决此问题的一种非常简单的方法。

确定

如果您使用的是语句缓存，c3p0将在连接中没有合适的缓存语句可用时异步获取缓存语句。在高负载和未仔细配置的情况下，由于服务器拥塞或c3p0线程池拥塞，此异步获取可能需要很长时间。试图获取语句的客户端将无限期地等待，直到成功获取该语句或发生异常为止

从根本原因异常（一直向下到堆栈跟踪的底部）可以清楚地看到，当潜在的长语句获取发生时，从中获取语句的连接关闭或终止。这就是您需要调试才能真正理解这一点的原因。可能的原因包括：

在这种情况下，负载/网络问题/神秘的小精灵偶尔会破坏连接，导致连接无效并关闭（）

DBMS或某些管理监视程序close（）会关闭这些（可能是长时间挂起的）连接，因为打开的连接太多或打开的时间太长。（可能这是死锁检测器的工作。）

您的应用程序（不明智地）在多个线程中使用连接，其中一个线程调用close（），而另一个线程仍在等待（）语句。然后池（出于多种原因之一）尝试close（）关闭签入连接，从而导致此错误

如果（3）是这种情况，你应该停止这样做，但我认为这是最不可能发生的情况。如果（1）或（2），你可以缓解这个问题的主要方法是确保语句获取速度很快，这样在我们等待语句时，不太可能发生不好的事情

我要看的第一件事是c3p0的线程池在您的应用程序所处的负载条件下。它能保持吗？（您可以通过JMX或对PooledDataSource方法（如或）的调用来检查这一点，最简单的方法是简单地放大c3p0配置参数，因此语句获取之类的任务不太可能积压

另一个真正有帮助的配置更改是确保允许足够数量的缓存语句，以防止在状态中搅动（持续关闭）和重新获取连接

Caused by: java.sql.SQLException: A problem occurred while trying to acquire a cached PreparedStatement in a background thread.
   at com.mchange.v2.c3p0.stmt.GooGooStatementCache.acquireStatement(GooGooStatementCache.java:571)
   at com.mchange.v2.c3p0.stmt.GooGooStatementCache.checkoutStatement(GooGooStatementCache.java:204)
   at com.mchange.v2.c3p0.impl.NewPooledConnection.checkoutStatement(NewPooledConnection.java:321)
   at com.mchange.v2.c3p0.impl.NewProxyConnection.prepareStatement(NewProxyConnection.java:431)
   at org.hibernate.engine.jdbc.internal.StatementPreparerImpl$3.doPrepare(StatementPreparerImpl.java:117)
   at org.hibernate.engine.jdbc.internal.StatementPreparerImpl$StatementPreparationTemplate.prepareStatement(StatementPreparerImpl.java:172)
   ... 29 more
Caused by: java.sql.SQLException: Invalid argument(s) in call
   at oracle.jdbc.driver.AutoKeyInfo.getNewSql(AutoKeyInfo.java:187)
   at oracle.jdbc.driver.PhysicalConnection.prepareStatement(PhysicalConnection.java:4342)
   at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
   at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
   at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
   at java.lang.reflect.Method.invoke(Method.java:498)
   at com.mchange.v2.c3p0.stmt.GooGooStatementCache$1StmtAcquireTask.run(GooGooStatementCache.java:547)
   at com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:696)