Commit 61f58489 authored by Jeremy Hylton's avatar Jeremy Hylton

Catch errors that current during 2nd phase of 2PC.

It's not clear what the right answer is here.  The implementation
aborts any remaining resource managers and hopes for the best, which
isn't very satisfying.  Perhaps the hosed feature should come back.

Add some comments about the issues involved.  Revise the tests to
cover the current behavior.
parent 7b9e4469
import logging import logging
import sys
from transaction.interfaces import * from transaction.interfaces import *
from transaction.txn import Transaction, Status, Set from transaction.txn import Transaction, Status, Set
...@@ -38,14 +39,28 @@ class AbstractTransactionManager(object): ...@@ -38,14 +39,28 @@ class AbstractTransactionManager(object):
def _finishCommit(self, txn): def _finishCommit(self, txn):
self.logger.debug("%s: commit", txn) self.logger.debug("%s: commit", txn)
# finish the two-phase commit try:
for r in txn._resources: for r in txn._resources:
r.commit(txn) r.commit(txn)
txn._status = Status.COMMITTED txn._status = Status.COMMITTED
except:
# An error occured during the second phase of 2PC. We can
# no longer guarantee the system is in a consistent state.
# The best we can do is abort() all the resource managers
# that haven't already committed and hope for the best.
error = sys.exc_info()
txn._status = Status.FAILED
self.abort(txn)
msg = ("Transaction failed during second phase of two-"
"phase commmit")
self.logger.critical(msg, exc_info=error)
raise TransactionError("Transaction failed during second "
"phase of two-phase commit")
def abort(self, txn): def abort(self, txn):
self.logger.debug("%s: abort", txn) self.logger.debug("%s: abort", txn)
assert txn._status in (Status.ACTIVE, Status.PREPARED, Status.FAILED) assert txn._status in (Status.ACTIVE, Status.PREPARED, Status.FAILED,
Status.ABORTED)
txn._status = Status.PREPARING txn._status = Status.PREPARING
for r in txn._resources: for r in txn._resources:
r.abort(txn) r.abort(txn)
......
...@@ -80,7 +80,6 @@ class BaseTxnTests(unittest.TestCase): ...@@ -80,7 +80,6 @@ class BaseTxnTests(unittest.TestCase):
self.assertEqual(txn.status(), Status.ABORTED) self.assertEqual(txn.status(), Status.ABORTED)
self.assertRaises(IllegalStateError, txn.commit) self.assertRaises(IllegalStateError, txn.commit)
self.assertRaises(IllegalStateError, txn.savepoint) self.assertRaises(IllegalStateError, txn.savepoint)
self.assertRaises(IllegalStateError, txn.abort)
def testTrivialSavepoint(self): def testTrivialSavepoint(self):
txn = self.manager.begin() txn = self.manager.begin()
...@@ -131,6 +130,14 @@ class BaseTxnTests(unittest.TestCase): ...@@ -131,6 +130,14 @@ class BaseTxnTests(unittest.TestCase):
self.assertRaises(IllegalStateError, txn.commit) self.assertRaises(IllegalStateError, txn.commit)
txn.abort() txn.abort()
def testCommitFailure(self):
txn = self.manager.begin()
txn.join(TestDataManager())
txn.join(TestDataManager(fail="commit"))
self.assertRaises(TransactionError, txn.commit)
self.assertEqual(txn.status(), Status.ABORTED)
txn.abort()
class SimpleTxnTests(BaseTxnTests): class SimpleTxnTests(BaseTxnTests):
ManagerFactory = TransactionManager ManagerFactory = TransactionManager
......
...@@ -64,6 +64,8 @@ class Transaction: ...@@ -64,6 +64,8 @@ class Transaction:
def abort(self): def abort(self):
"""Rollback to initial state.""" """Rollback to initial state."""
assert self._manager is not None assert self._manager is not None
if self._status == Status.ABORTED:
return
if self._status not in (Status.ACTIVE, Status.PREPARED, Status.FAILED): if self._status not in (Status.ACTIVE, Status.PREPARED, Status.FAILED):
raise IllegalStateError("abort", self._status) raise IllegalStateError("abort", self._status)
self._manager.abort(self) self._manager.abort(self)
......
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