And how to roll ’em back:
Stop Spine/MQ and query dba_2pc_pending and/or dba_pending_transactions.
As sysdba :
rollback force 'local_tran_id#';
exec dbms_transaction.purge_lost_db_entry('local_tran_id#');
commit;
Et voila…
Sources: Admin_guide DBA_2PC_NEIGHBORS DBA_2PC_PENDING DBA_PENDING_TRANSACTIONS