Operations on a failed transaction can succeed

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    • Type: Bug
    • Resolution: Unresolved
    • Priority: Minor - P4
    • None
    • Affects Version/s: None
    • Component/s: Transactions
    • None
    • Storage Engines, Storage Engines - Transactions
    • SE Transactions - 2025-08-29
    • 5

      During randomized API testing for an ongoing MongoDB Research project, we found that continuing to issue operations on a failed transaction will succeed in some cases. As in, an insert fails with WT_ROLLBACK, and then another insert on that same transaction will report success.

      Here is code to reproduce the issue, courtesy of Peter Macko:

      self.session.create(self.uri, 'key_format=S,value_format=S')

session1 = self.conn.open_session()
cursor1 = session1.open_cursor(self.uri, None)
session1.begin_transaction()
cursor1['A'] = 'A1'

session2 = self.conn.open_session()
session2.begin_transaction()
cursor2 = session2.open_cursor(self.uri, None)
cursor2.set_key('A')
cursor2.set_value('A2')
cursor2.insert() # <----- fails with WT_ROLLBACK as expected

cursor2.set_key('B')
cursor2.set_value('B2')
cursor2.insert() # <----- succeeds, even though the transaction has already failed

session1.commit_transaction()
session2.commit_transaction()   # <----- fails with "failed transaction requires rollback: Invalid argument"
session2.rollback_transaction() # <----- fails with "only permitted in a running transaction: Invalid argument"

session1.close()
session2.close()

              Assignee:
              Vamsi Boyapati
              Reporter:
              Finn Hackett (Inactive)
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                Created:
                Updated: