Java MySQL连接池在空闲几分钟时通信失败

我与来自Java的MySQL服务器的连接有问题。它是一个远程MySQL服务器。我用的是玻璃鱼4。我使用连接池和jdbc连接到数据库

空闲几分钟后，连接链路断开。服务器尝试重新连接几次，但失败，然后引发

通信链路故障

异常。以下是完整的堆栈跟踪：

   Info:   Communication failure detected when attempting to perform read query outside of a transaction. Attempting to retry query. Error was: Exception [EclipseLink-4002] (Eclipse Persistence Services - 2.5.2.v20140319-9ad6abd): org.eclipse.persistence.exceptions.DatabaseException
    Internal Exception: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure
    The last packet successfully received from the server was 580,803 milliseconds ago.  The last packet sent successfully to the server was 21,302 milliseconds ago.
    Error Code: 0
    Call: SELECT payload FROM session WHERE (id = ?)
            bind => [1 parameter bound]
    Query: ReportQuery(name="Session.findAuthorBySession" referenceClass=Session sql="SELECT payload FROM session WHERE (id = ?)").
    Info:   Communication failure detected when attempting to perform read query outside of a transaction. Attempting to retry query. Error was: Exception [EclipseLink-4002] (Eclipse Persistence Services - 2.5.2.v20140319-9ad6abd): org.eclipse.persistence.exceptions.DatabaseException
    Internal Exception: com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: No operations allowed after connection closed.
    Error Code: 0

在这里，它尝试再重新连接几次（10-15次），然后抛出以下命令：

Query: ReportQuery(name="Session.findAuthorBySession" referenceClass=Session sql="SELECT payload FROM session WHERE (id = ?)").
Warning:   Local Exception Stack: 
Exception [EclipseLink-4002] (Eclipse Persistence Services - 2.5.2.v20140319-9ad6abd): org.eclipse.persistence.exceptions.DatabaseException
Internal Exception: com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: No operations allowed after connection closed.
Error Code: 0
Call: SELECT payload FROM session WHERE (id = ?)
    bind => [1 parameter bound]
Query: ReportQuery(name="Session.findAuthorBySession" referenceClass=Session sql="SELECT payload FROM session WHERE (id = ?)")
    at org.eclipse.persistence.exceptions.DatabaseException.sqlException(DatabaseException.java:340)
    at org.eclipse.persistence.internal.databaseaccess.DatabaseAccessor.processExceptionForCommError(DatabaseAccessor.java:1611)
    at org.eclipse.persistence.internal.databaseaccess.DatabaseAccessor.basicExecuteCall(DatabaseAccessor.java:674)
    at org.eclipse.persistence.internal.databaseaccess.DatabaseAccessor.executeCall(DatabaseAccessor.java:558)
    at org.eclipse.persistence.internal.sessions.AbstractSession.basicExecuteCall(AbstractSession.java:2002)
    at org.eclipse.persistence.sessions.server.ServerSession.executeCall(ServerSession.java:570)
    at org.eclipse.persistence.internal.queries.DatasourceCallQueryMechanism.executeCall(DatasourceCallQueryMechanism.java:242)
    at org.eclipse.persistence.internal.queries.DatasourceCallQueryMechanism.executeCall(DatasourceCallQueryMechanism.java:228)
    at org.eclipse.persistence.internal.queries.DatasourceCallQueryMechanism.executeSelectCall(DatasourceCallQueryMechanism.java:299)
    at org.eclipse.persistence.internal.queries.DatasourceCallQueryMechanism.selectAllRows(DatasourceCallQueryMechanism.java:694)
    at org.eclipse.persistence.internal.queries.ExpressionQueryMechanism.selectAllRowsFromTable(ExpressionQueryMechanism.java:2738)
    at org.eclipse.persistence.internal.queries.ExpressionQueryMechanism.selectAllReportQueryRows(ExpressionQueryMechanism.java:2675)
    at org.eclipse.persistence.queries.ReportQuery.executeDatabaseQuery(ReportQuery.java:848)
    at org.eclipse.persistence.queries.DatabaseQuery.execute(DatabaseQuery.java:899)
    at org.eclipse.persistence.queries.ObjectLevelReadQuery.execute(ObjectLevelReadQuery.java:1127)
    at org.eclipse.persistence.queries.ReadAllQuery.execute(ReadAllQuery.java:403)
    at org.eclipse.persistence.queries.ObjectLevelReadQuery.executeInUnitOfWork(ObjectLevelReadQuery.java:1215)
    at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.internalExecuteQuery(UnitOfWorkImpl.java:2896)
    at org.eclipse.persistence.internal.sessions.AbstractSession.executeQuery(AbstractSession.java:1804)
    at org.eclipse.persistence.internal.sessions.AbstractSession.retryQuery(AbstractSession.java:1874)
    at org.eclipse.persistence.sessions.server.ClientSession.retryQuery(ClientSession.java:687)
    at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.retryQuery(UnitOfWorkImpl.java:5538)
    at org.eclipse.persistence.internal.sessions.AbstractSession.executeQuery(AbstractSession.java:1840)
    at org.eclipse.persistence.internal.sessions.AbstractSession.retryQuery(AbstractSession.java:1874)
    at org.eclipse.persistence.sessions.server.ClientSession.retryQuery(ClientSession.java:687)
    at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.retryQuery(UnitOfWorkImpl.java:5538)
    at org.eclipse.persistence.internal.sessions.AbstractSession.executeQuery(AbstractSession.java:1840)
    at org.eclipse.persistence.internal.sessions.AbstractSession.retryQuery(AbstractSession.java:1874)
    at org.eclipse.persistence.sessions.server.ClientSession.retryQuery(ClientSession.java:687)
    at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.retryQuery(UnitOfWorkImpl.java:5538)
    at org.eclipse.persistence.internal.sessions.AbstractSession.executeQuery(AbstractSession.java:1840)
    at org.eclipse.persistence.internal.sessions.AbstractSession.retryQuery(AbstractSession.java:1874)
    at org.eclipse.persistence.sessions.server.ClientSession.retryQuery(ClientSession.java:687)
    at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.retryQuery(UnitOfWorkImpl.java:5538)
    at org.eclipse.persistence.internal.sessions.AbstractSession.executeQuery(AbstractSession.java:1840)
    at org.eclipse.persistence.internal.sessions.AbstractSession.executeQuery(AbstractSession.java:1786)
    at org.eclipse.persistence.internal.sessions.AbstractSession.executeQuery(AbstractSession.java:1751)
    at org.eclipse.persistence.internal.jpa.QueryImpl.executeReadQuery(QueryImpl.java:258)
    at org.eclipse.persistence.internal.jpa.QueryImpl.getSingleResult(QueryImpl.java:517)
    at org.eclipse.persistence.internal.jpa.EJBQueryImpl.getSingleResult(EJBQueryImpl.java:400)

注:

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奇怪的是：我正在使用localhost测试一些新功能，然后部署到jelasticcloud。这样就不会出现这个问题（但这可能是由于一些差异造成的，比如ip被更改为机器的本地主机等）

哪个连接池？您是否正确配置了它？是的，连接池配置正确。@ashcrok，您目前的JDBC URL是什么？