The server.log file shows this message over and over:
2019-07-02 09:41:24,549 WARN [org.jboss.jca.adapters.jdbc.local.LocalManagedConnectionFactory] (ConnectionValidator) IJ030027: Destroying connection that is not valid, due to the following exception:
[email protected]: java.sql.SQLSyntaxErrorException: ORA-00923: FROM keyword not found where expected
at oracle.jdbc.driver.T4CTTIoer.processError(T4CTTIoer.java:450)
at oracle.jdbc.driver.T4CTTIoer.processError(T4CTTIoer.java:399)
at oracle.jdbc.driver.T4C8Oall.processError(T4C8Oall.java:1059)
at oracle.jdbc.driver.T4CTTIfun.receive(T4CTTIfun.java:522)
at oracle.jdbc.driver.T4CTTIfun.doRPC(T4CTTIfun.java:257)
at oracle.jdbc.driver.T4C8Oall.doOALL(T4C8Oall.java:587)
at oracle.jdbc.driver.T4CStatement.doOall8(T4CStatement.java:210)
at oracle.jdbc.driver.T4CStatement.doOall8(T4CStatement.java:30)
at oracle.jdbc.driver.T4CStatement.executeForDescribe(T4CStatement.java:762)
at oracle.jdbc.driver.OracleStatement.executeMaybeDescribe(OracleStatement.java:925)
at oracle.jdbc.driver.OracleStatement.doExecuteWithTimeout(OracleStatement.java:1111)
at oracle.jdbc.driver.OracleStatement.executeInternal(OracleStatement.java:1792)
at oracle.jdbc.driver.OracleStatement.execute(OracleStatement.java:1745)
at oracle.jdbc.driver.OracleStatementWrapper.execute(OracleStatementWrapper.java:334)
at org.jboss.jca.adapters.jdbc.CheckValidConnectionSQL.isValidConnection(CheckValidConnectionSQL.java:74)
at org.jboss.jca.adapters.jdbc.BaseWrapperManagedConnectionFactory.isValidConnection(BaseWrapperManagedConnectionFactory.java:1273)
at org.jboss.jca.adapters.jdbc.BaseWrapperManagedConnectionFactory.getInvalidConnections(BaseWrapperManagedConnectionFactory.java:1086)
at org.jboss.jca.core.connectionmanager.pool.mcp.SemaphoreConcurrentLinkedDequeManagedConnectionPool.validateConnections(SemaphoreConcurrentLinkedDequeManagedConnectionPool.java:1443)
at org.jboss.jca.core.connectionmanager.pool.validator.ConnectionValidator$ConnectionValidatorRunner.run(ConnectionValidator.java:277)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)