Occasional errors from ORM unable to get a JDBC connection on shutdown

[Sanne]

The following (swallowed) exception could happen on shutdown:

2019-04-08 11:48:54,928 WARN  [io.qua.hib.orm.run.JPAConfig] (Quarkus Shutdown Thread) Unable to close the EntityManagerFactory: io.quarkus.hibernate.orm.runtime.JPAConfig$LazyPersistenceUnit@36f44211: org.hibernate.exception.GenericJDBCException: Unable to open JDBC Connection for DDL execution
    at org.hibernate.exception.internal.StandardSQLExceptionConverter.convert(StandardSQLExceptionConverter.java:47)
    at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:113)
    at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:99)
    at org.hibernate.resource.transaction.backend.jta.internal.DdlTransactionIsolatorJtaImpl.<init>(DdlTransactionIsolatorJtaImpl.java:62)
    at org.hibernate.resource.transaction.backend.jta.internal.JtaTransactionCoordinatorBuilderImpl.buildDdlTransactionIsolator(JtaTransactionCoordinatorBuilderImpl.java:46)
    at org.hibernate.tool.schema.internal.SchemaDropperImpl$DelayedDropActionImpl.perform(SchemaDropperImpl.java:528)
    at org.hibernate.internal.SessionFactoryImpl.close(SessionFactoryImpl.java:813)
    at io.quarkus.hibernate.orm.runtime.JPAConfig$LazyPersistenceUnit.close(JPAConfig.java:126)
    at io.quarkus.hibernate.orm.runtime.JPAConfig.destroy(JPAConfig.java:89)
    at io.quarkus.hibernate.orm.runtime.JPAConfig_Bean.destroy(Unknown Source)
    at io.quarkus.hibernate.orm.runtime.JPAConfig_Bean.destroy(Unknown Source)
    at io.quarkus.arc.InstanceHandleImpl.destroyInternal(InstanceHandleImpl.java:89)
    at io.quarkus.arc.ContextInstanceHandleImpl.destroy(ContextInstanceHandleImpl.java:34)
    at io.quarkus.arc.AbstractSharedContext.destroy(AbstractSharedContext.java:79)
    at io.quarkus.arc.ArcContainerImpl.shutdown(ArcContainerImpl.java:270)
    at io.quarkus.arc.Arc.shutdown(Arc.java:53)
    at io.quarkus.arc.runtime.ArcDeploymentTemplate$1.run(ArcDeploymentTemplate.java:53)
    at io.quarkus.runtime.StartupContext.close(StartupContext.java:59)
    at io.quarkus.runner.ApplicationImpl2.doStop(Unknown Source)
    at io.quarkus.runtime.Application.stop(Application.java:163)
    at io.quarkus.runner.RuntimeRunner$1.close(RuntimeRunner.java:127)
    at io.quarkus.runner.RuntimeRunner.close(RuntimeRunner.java:77)
    at io.quarkus.dev.DevModeMain$1.run(DevModeMain.java:73)
    at java.lang.Thread.run(Thread.java:748)
Caused by: java.sql.SQLException: This pool is closed and does not handle any more connections!
    at io.agroal.pool.ConnectionPool.getConnection(ConnectionPool.java:138)
    at io.agroal.pool.DataSource.getConnection(DataSource.java:61)
    at org.hibernate.engine.jdbc.connections.internal.DatasourceConnectionProviderImpl.getConnection(DatasourceConnectionProviderImpl.java:122)
    at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator$ConnectionProviderJdbcConnectionAccess.obtainConnection(JdbcEnvironmentInitiator.java:180)
    at org.hibernate.resource.transaction.backend.jta.internal.DdlTransactionIsolatorJtaImpl.<init>(DdlTransactionIsolatorJtaImpl.java:59)

The problem being that Hibernate ORM was configured to drop the database on shutdown, but the destroy order is random.

It could happen that ORM would be shut down only after the Datasource pools was already shutdown.