Last update: 4 August 2017
The error message "XA_PREPARE failed" with errorcode xaerr= '-3' indicates that the Dirstributed Transaction manager (DTM) could not connect to the Oracle XA-Service.
Whenever this happens the DTM subsequently tries to rollback the transaction. This rollback therefore can not be accomplished because the Oracle Database already rollbacked but without the DTM knowing. From now on the DTM still tries to rollback continuously until a timout is reached.
To resolve this issue, a start of the COO-Services in the "Recovery Mode" must be done. The "Recovery Mode" implicitly purges the DTM logs. ( http://help.fabasoftfolio.com/doc/Fabasoft-Folio-Distributed-Transaction-Manager/recovery-mode.htm )
Additionally pending transactions must be deleted in the Oracle Database.
Warning: Please consider that the solution provided below requires a complete domain restart!
After ensuring that the settings described above are correctly configured
select * from sys.dba_pending_transactions
select * from dba_2pc_pending
while using an Oracle database