Hi On a server we have a ZEO server with 6 clients. When we start/restart the server we often get on random instance an AttributeError @@plone and all other browser pages. I have tracked it down to a ConflictError when installing Five on startup. See traceback bellow. To solve this I tried to set enable-product-installation = off to all except one instance but I still got errors. For now we restart the broken instances until they work, I have tried to set sleeping times up to couple seconds between the instances but it didn't make any difference. Five fails when it tries to execute the registerPackage in zcml files. Not the same product every time. First I thought it didn't respect the enable-product-instalation but that is checked in App.Product.initializeProduct method. So I played in fiveconfigure.py with transaction.savepoint() but no success but if I manually check App.Product.doInstall like in the diff below Now my question is if this is correct solution for the problem or will it have other side effects that I am not aware of? How do I write tests for an ConflicError during startup? /Sasha Index: fiveconfigure.py =================================================================== --- fiveconfigure.py (revision 86781) +++ fiveconfigure.py (working copy) @@ -23,7 +23,7 @@ import warnings import App.config -from App.Product import initializeProduct +from App.Product import initializeProduct, doInstall from App.ProductContext import ProductContext import Products from zLOG import LOG, ERROR @@ -265,6 +265,8 @@ if not hasattr(module_, '__path__'): raise ValueError("Must be a package and the " \ "package must be filesystem based") + if not doInstall(): + return app = Zope2.app() try: 2008-05-16 11:48:17 ERROR Zope Couldn't install Five Traceback (most recent call last): File "/Users/sasha/Development/eea-buildout-clean/parts/zope2/lib/python/OFS/Application.py", line 783, in install_product initmethod(context) File "/Users/sasha/Development/eea-buildout-clean/products/Five/__init__.py", line 31, in initialize zcml.load_site() File "/Users/sasha/Development/eea-buildout-clean/products/Five/zcml.py", line 41, in load_site _context = xmlconfig.file(file) File "/Users/sasha/Development/eea-buildout-clean/parts/zope2/lib/python/zope/configuration/xmlconfig.py", line 560, in file context.execute_actions() File "/Users/sasha/Development/eea-buildout-clean/parts/zope2/lib/python/zope/configuration/config.py", line 612, in execute_actions callable(*args, **kw) File "/Users/sasha/Development/eea-buildout-clean/products/Five/fiveconfigure.py", line 285, in _registerPackage transaction.commit() File "/Users/sasha/Development/eea-buildout-clean/parts/zope2/lib/python/transaction/_manager.py", line 96, in commit return self.get().commit(sub, deprecation_wng=False) File "/Users/sasha/Development/eea-buildout-clean/parts/zope2/lib/python/transaction/_transaction.py", line 380, in commit self._saveCommitishError() # This raises! File "/Users/sasha/Development/eea-buildout-clean/parts/zope2/lib/python/transaction/_transaction.py", line 378, in commit self._commitResources() File "/Users/sasha/Development/eea-buildout-clean/parts/zope2/lib/python/transaction/_transaction.py", line 433, in _commitResources rm.commit(self) File "/Users/sasha/Development/eea-buildout-clean/parts/zope2/lib/python/ZODB/Connection.py", line 484, in commit self._commit(transaction) File "/Users/sasha/Development/eea-buildout-clean/parts/zope2/lib/python/ZODB/Connection.py", line 518, in _commit raise ConflictError(object=obj) ConfigurationExecutionError: ZODB.POSException.ConflictError: database conflict error (oid 0x28f61f, class App.Product.Product) in: File "/Users/sasha/Development/eea-buildout-clean/src/plone.session/plone/session/configure.zcml", line 5.4-5.65 <five:registerPackage package="." initialize=".initialize" /> Traceback (most recent call last): File "/Users/sasha/Development/eea-buildout-clean/parts/zope2/lib/python/Zope2/Startup/run.py", line 56, in ? run() File "/Users/sasha/Development/eea-buildout-clean/parts/zope2/lib/python/Zope2/Startup/run.py", line 21, in run starter.prepare() File "/Users/sasha/Development/eea-buildout-clean/parts/zope2/lib/python/Zope2/Startup/__init__.py", line 98, in prepare self.startZope() File "/Users/sasha/Development/eea-buildout-clean/parts/zope2/lib/python/Zope2/Startup/__init__.py", line 257, in startZope Zope2.startup() File "/Users/sasha/Development/eea-buildout-clean/parts/zope2/lib/python/Zope2/__init__.py", line 47, in startup _startup() File "/Users/sasha/Development/eea-buildout-clean/parts/zope2/lib/python/Zope2/App/startup.py", line 103, in startup OFS.Application.initialize(application) File "/Users/sasha/Development/eea-buildout-clean/parts/zope2/lib/python/OFS/Application.py", line 304, in initialize initializer.initialize() File "/Users/sasha/Development/eea-buildout-clean/parts/zope2/lib/python/OFS/Application.py", line 333, in initialize self.install_products() File "/Users/sasha/Development/eea-buildout-clean/parts/zope2/lib/python/OFS/Application.py", line 605, in install_products return install_products(app) File "/Users/sasha/Development/eea-buildout-clean/parts/zope2/lib/python/OFS/Application.py", line 636, in install_products folder_permissions, raise_exc=debug_mode) File "/Users/sasha/Development/eea-buildout-clean/parts/zope2/lib/python/OFS/Application.py", line 783, in install_product initmethod(context) File "/Users/sasha/Development/eea-buildout-clean/products/Five/__init__.py", line 31, in initialize zcml.load_site() File "/Users/sasha/Development/eea-buildout-clean/products/Five/zcml.py", line 41, in load_site _context = xmlconfig.file(file) File "/Users/sasha/Development/eea-buildout-clean/parts/zope2/lib/python/zope/configuration/xmlconfig.py", line 560, in file context.execute_actions() File "/Users/sasha/Development/eea-buildout-clean/parts/zope2/lib/python/zope/configuration/config.py", line 612, in execute_actions callable(*args, **kw) File "/Users/sasha/Development/eea-buildout-clean/products/Five/fiveconfigure.py", line 285, in _registerPackage transaction.commit() File "/Users/sasha/Development/eea-buildout-clean/parts/zope2/lib/python/transaction/_manager.py", line 96, in commit return self.get().commit(sub, deprecation_wng=False) File "/Users/sasha/Development/eea-buildout-clean/parts/zope2/lib/python/transaction/_transaction.py", line 380, in commit self._saveCommitishError() # This raises! File "/Users/sasha/Development/eea-buildout-clean/parts/zope2/lib/python/transaction/_transaction.py", line 378, in commit self._commitResources() File "/Users/sasha/Development/eea-buildout-clean/parts/zope2/lib/python/transaction/_transaction.py", line 433, in _commitResources rm.commit(self) File "/Users/sasha/Development/eea-buildout-clean/parts/zope2/lib/python/ZODB/Connection.py", line 484, in commit self._commit(transaction) File "/Users/sasha/Development/eea-buildout-clean/parts/zope2/lib/python/ZODB/Connection.py", line 518, in _commit raise ConflictError(object=obj) zope.configuration.config.ConfigurationExecutionError: ZODB.POSException.ConflictError: database conflict error (oid 0x28f61f, class App.Product.Product) in: File "/Users/sasha/Development/eea-buildout-clean/src/plone.session/plone/session/configure.zcml", line 5.4-5.65 <five:registerPackage package="." initialize=".initialize" />