Perry wrote at 2007-5-25 13:16 +0200:
database conflict error (oid 0x7905e6, class BTrees._IOBTree.IOBucket, serial this txn started with 0x036ddc2a44454dee 2007-05-25 09:14:16.000950, serial currently committed 0x036ddc2c21950377 2007-05-25 09:16:07.870801) (80 conflicts (10 unresolved) since startup at Fri May 25 05:19:08 2007) ... ConflictError: database conflict error (oid 0x7905e6, class BTrees._IOBTree.IOBucket, serial this txn started with 0x036ddc2b3e989fdd 2007-05-25 09:15:14.670982, serial currently committed 0x036ddc2dd48f4e33 2007-05-25 09:17:49.818700)
These log entries indicate a bug in ZODB's invalidation processing. The first entry tells us that the object was read at 9:14:16 and the modification conflicts with a write from 9:16:07. The second entry tells us that the object was read at 9:15:14 *BUT* at the time this transaction has started, the ZODB should already have known the modification from 9:16:07 and the object read at 9:15:14 should have been invalidated. The new transaction should not have seen any state older than 9:16:07 (as it begins after this time). In older ZODB versions, there has been a bug in "ZODB.Connection.Connection._setDB". It has forgotten to flush invalidations (which may lead to observations as the above). In our private Zope version, I have still a note like this: # DM 2005-08-22: always call '_flush_invalidations' as it does # more than cache handling only self._flush_invalidations() if self._reset_counter != global_reset_counter: # New code is in place. Start a new cache. self._resetCache() # DM 2005-08-22: always call '_flush_invalidations' ## else: ## self._flush_invalidations() The note indicates that the bug was fixed at least at 2005-08-22 (though the handling was not completely right in case the cache was reset). Maybe, the bug you see now affects only mounted connections? -- Dieter