-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Joachim Schmitz wrote:
some more findings:
1. The conflict error really happens on the Portalcatalog 2. It is a BTreesConflictError: BTrees conflict error at -1/47/47: Conflicting inserts which disguised as ConflictError, through the various try: excepts:
3. It happens on DateIndexes like "created" and "modified".
4. I put for a test: try: resolved = resolve(old, committed, newstate) except: return "invalidated"
into tryToResolveConflict
and into the store-method of FileStorage:
if serial != cached_tid: rdata = self.tryToResolveConflict(oid, cached_tid,serial, data) if rdata is None: raise POSException.ConflictError(oid=oid, serials=(cached_tid, serial), data=data) elif rdata == "invalidated": #new for test old = False # pass #
With these hacks I get rid of the conflictErrors. But when I delete the created Items I get: 2007-06-01 13:20:33 ERROR Zope.UnIndex DateIndex: unindex_object tried to retrieve set 1075379718 from index created but couldn't. This should not happen. 2007-06-01 13:20:33 ERROR Zope.UnIndex DateIndex: unindex_object tried to retrieve set 1075379838 from index Date but couldn't. This should not happen. 2007-06-01 13:20:33 ERROR Zope.UnIndex DateIndex: unindex_object tried to retrieve set 1075379719 from index modified but couldn't. This should not happen.
So obviously I just fix the symptom with this hack. I think the real cause:
lies in these lines:
if old: cached_tid = self._get_cached_tid(oid) if cached_tid is None: h = self._read_data_header(old, oid) if h.version: if h.version != version: raise VersionLockError(oid, h.version) pnv = h.pnv cached_tid = h.tid
if serial != cached_tid: rdata = self.tryToResolveConflict(oid, cached_tid,serial, data)
Which is also supported by the fact, that on our live system which is running on 4 zeo-clients we get this traceback:
2007-06-01T12:38:59 ERROR Zope.SiteErrorLog http://uniben.waeup.org/campus/students/F541700/study_course/create_level Traceback (innermost last): Module Zope2.App.startup, line 173, in zpublisher_exception_hook Module ZPublisher.Publish, line 121, in publish Module Zope2.App.startup, line 240, in commit Module transaction._manager, line 96, in commit Module Products.CPSCompat.PatchZODBTransaction, line 175, in commit Module transaction._transaction, line 436, in _commitResources Module ZODB.Connection, line 665, in tpc_vote Module ZEO.ClientStorage, line 893, in tpc_vote Module ZEO.ClientStorage, line 877, in _check_serials ConflictError: database conflict error (oid 0x8fe833, class BTrees._IOBTree.IOBucket, serial this txn started with 0x036e0418ddcccf55 2007-06-01 11:36:51.984384, serial currently committed 0x036e041a3a33e311 2007-06-01 11:38:13.641254)
Any suggestion for a temporary fix would be very welcome, since we get about 6000 conflict errors per day now about 15 % unresolved, and they are really killing our portal.
A workaround might be to replace the DateIndexes for 'created' and 'modified' with FieldIndexes: you will see a big jump in the number of keys in the index, but (perhaps) a reduction in conflicts (altheough there will be more bucket splits, which can also cause conflicts). A longer term solution might be to come up with a derived index type which used non-persistent objects (rather than the IITreeSet used by UnIndex) for the set of RIDs stored under each 'minute': you could then inspect the state and do more aggressive conflict resolution than the stock implementation allows (see my other post). Tres. - -- =================================================================== Tres Seaver +1 540-429-0999 tseaver@palladion.com Palladion Software "Excellence by Design" http://palladion.com -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFGYB4w+gerLs4ltQ4RAhsLAJ9/TR4unlzPMQBY7gfpT6WmQZovywCfQrAF EnkttfiHM7gk1ENrm+ineA4= =oJqE -----END PGP SIGNATURE-----