Interesting issue in a SOA/BPM today.
Redeployment of the application (SOA) and restart went through without an issue.
However the stresstest came back almost immediately. The AdminServer.out showed the error "A call to flushChanges on the current MDSSession does not specify the correct transaction key". Even more astonishing was the error TNS-12516 when trying to connect to the database.
After a little bit of searching we found that the database alert log said it could not extend the SOA_INFRA tablespace.
Adapted this and everything went back to normal.