Bug: StatefulServiceInterfacePrx.close throws UnknownException rather than InternalException

[jamoore]

Exception in thread Thread-5:
Traceback (most recent call last):
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/threading.py", line 532, in __bootstrap_inner
    self.run()
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/threading.py", line 484, in run
    self.__target(*self.__args, **self.__kwargs)
  File "./threaders.py", line 25, in go
    rv = client.upload("test.txt")
  File "/Users/moore/code/git/dist/lib/python/omero/clients.py", line 621, in upload
    prx.setFileId(ofile.id.val)
  File "/Users/moore/code/git/dist/lib/python/omero_api_RawFileStore_ice.py", line 85, in setFileId
    return _M_omero.api.RawFileStore._op_setFileId.invoke(self, ((fileId, ), _ctx))
UnknownException: exception ::Ice::UnknownException
{
    unknown = org.springframework.transaction.TransactionSystemException: Could not roll back JDBC transaction; nested exception is org.postgresql.util.PSQLException: An I/O error occured while sending to the backend.
	at org.springframework.jdbc.datasource.DataSourceTransactionManager.doRollback(DataSourceTransactionManager.java:286)
	at org.springframework.transaction.support.AbstractPlatformTransactionManager.processRollback(AbstractPlatformTransactionManager.java:845)
	at org.springframework.transaction.support.AbstractPlatformTransactionManager.rollback(AbstractPlatformTransactionManager.java:822)
	at org.springframework.transaction.interceptor.TransactionAspectSupport.completeTransactionAfterThrowing(TransactionAspectSupport.java:430)
	at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:112)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)

[jmoore]

This is most likely a result of connection poisoning happening from very large "select ... where id in (:ids)" statements. See #5858