Package: zodbupdate
This package provides a tool that automatically identifies and updates
references from persistent objects to classes that are in the process of being
moved from one module to another and/or being renamed.If a class is being moved or renamed, you need to update all references from
your database to the new name before finally deleting the old code.This tool looks through all current objects of your database,
identifies moved/renamed classes andtouchesobjects accordingly. It
creates transactions that contains the update of your database (one
transaction every 100,000 records).Having run this tool, you are then free to delete the old code.ContentsUsageCustom software/eggsNon-FileStorage configurationsPre-defined rename rulesPackingConverting to Python 3Converting to Python 3 from within Python 3Problems and solutionsYour Data.fs has POSKey errorsYou have another errorChanges2.0 (2023-02-09)1.5 (2020-07-28)1.4 (2019-08-23)1.3 (2019-07-30)1.2 (2019-05-09)1.1 (2018-10-05)1.0 (2018-02-13)0.5 (2010-10-07)0.4 (2010-07-14)0.3 (2010-02-02)0.2 (2009-06-23)0.1 (2009-06-08)UsageInstalling the egg of this tool provides a console scriptzodbupdatewhich
you can call giving either a FileStorage filename or a configuration file
defining a storage:$ zodbupdate -f Data.fs
$ zodbupdate -c zodb.confDetailed usage information is available:$ zodbupdate -hCustom software/eggsIt is important to install this egg in an interpreter/environment where your
software is installed as well. If you’re using a regular Python installation
or virtualenv, just installing the package using easy_install should be fine.If you are using buildout, installing can be done using the egg recipe with
this configuration:[buildout]
parts += zodbupdate

[zodbupdate]
recipe = zc.recipe.egg
eggs = zodbupdate
    <list additional eggs here>If you do not installzodbupdatetogether with the necessary software it
will report missing classes and not touch your database.Non-FileStorage configurationsYou can configure any storage known to your ZODB installation by providing a
ZConfig configuration file (similar to zope.conf). For example you can connect
to a ZEO server by providing a config filezeo.conf:<zeoclient>
    server 127.0.0.1:8100
    storage 1
</zeoclient>And then runningzodbupdateusing:$ zodbupdate -c zeo.confPre-defined rename rulesRename rules can be defined using an entry point calledzodbupdate:setup(...
      entry_points = """
      [zodbupdate]
      renames = mypackage.mymodule:rename_dict
      """)These can also be defined in python:setup(...
      entry_points={
        'zodbupdate': ['renames = mypackage.mymodule:rename_dict'],
      })Those entry points must points to dictionaries that map old class
names to new class names:rename_dict = {
    'mypackage.mymodule ClassName':
    'otherpackage.othermodule OtherClass'}As soon as you have rules defined, you can already remove the old
import location mentioned in them.PackingThe option--packwill pack the storage on success. (You tell your
users to use that option. If they never pack their storage, it is a good
occasion).Converting to Python 3zodbupdatecan be used to migrate a database created with a Python
2 application to be usable with the same application in Python 3. To
accomplish this, you need to:Stop your application. Nothing should be written to the database
while the migration is running.Update your Python 2 application to use the latest ZODB version. It
will not work with ZODB 3.With Python 2, runzodbupdate--pack--convert-py3.If you use a Data.fs we recommend you to use the-foption to
specify your database. After the conversion the magic header of the
database will be updated so that you will be able to open the database
with Python 3.If you use a different storage (like RelStorage), be sure you will be
connecting to it using your Python 3 application after the
migration. You will still be able to connect to your database and use
your application with Python 2 without errors, but then you will need
to convert it again to Python 3.While the pack is not required, it is highly recommended.The conversion will take care of the following tasks:Updating stored Python datetime, date and time objects to use
Python 3 bytes,Updating ZODB references to use Python 3 bytes.Optionally convert stored strings to either unicode or bytes pending
your configuration.If your application expect to use bytes in Python 3, they must be
stored as such in the database, and all other strings must be stored
as unicode string, if they contain other characters than ascii characters.When using--convert-py3,zodbupdatewill load a set of
decoders from the entry points:setup(...
      entry_points = """
      [zodbupdate.decode]
      decodes = mypackage.mymodule:decode_dict
      """)Decoders are dictionaries that specifies as keys attributes on
Persistent classes that must either be encoded as bytes (if the value
isbinary) or decoded to unicode using value as encoding (for
instanceutf-8here):decode_dict = {
   'mypackage.mymodule ClassName attribute': 'binary',
   'otherpackage.othermodule OtherClass other_attribute': 'utf-8'}Please note that for the moment only attributes on Persistent classes
are supported.Please also note that these conversion rules are _only_ selected for the
class that is referenced in the pickle, rules for superclasses are _not_
applied. This means that you have to push down annotation rules to all
the subclasses of a superclass that has a field that needs this annotation.Converting to Python 3 from within Python 3zodbupdatecan also be run from within Python 3 to convert a database
created with Python 2 to be usable in Python 3. However this works
slightly differently than when running the conversion using Python 2.
In Python 3 you must specify a default encoding to use while unpickling strings:zodbupdate--pack--convert-py3--encodingutf-8.For each string in the database, zodbupdate will convert it as follows:If it’s an attribute configured explicitly via a decoder as described
above, it will be decoded or encoded as specified there.Otherwise the value will be decoded using the encoding specified
on the command line.If there is an error while decoding using the encoding specified
on the command line, the value will be stored as bytes.Problems and solutionsYour Data.fs has POSKey errorsIf you callzodbupdatewith-fand the path to your Data.fs,
records triggering those errors will be ignored.You have another errorWe recommend to run zodbupdate with-v-dto get the
maximum of information.If you are working on big storages, you can use the option-oto
re-runzodbupdateat a failing record you previously encountered
afterward.Changes2.0 (2023-02-09)Add support for Python 3.9, 3.10, 3.11.Drop support for Python 2.7, 3.5, 3.6.Test with history-free and history-preserving RelStorage. Note that
history-preserving RelStorage requires RelStorage 3.3 or above, and
Python 2.7 or Python 3.6 and above.
(#30)1.5 (2020-07-28)Fixed incompatibility with ZODB 5.6
(#35)Added support for history-free RelStorage
(#28)Support zope.interface >= 5 in tests.
(issue 32)1.4 (2019-08-23)Fail with explanation when opening a Python 2 ZODB with –dry-run on Python 3
(#22)1.3 (2019-07-30)Support converting sets.Set() objects from ancient Python 2 versions.
(issue 23)Convert set objects tobuiltins.setwithout relying on ZODB.broken.rebuild.
(issue 25)1.2 (2019-05-09)Enable fallback encodings for Python 3 conversion for old/grown ZODBs using
the new command line option--encoding-fallback.
(#15)Switch to useargparseasoptparseis deprecated.Add ability to run the Python 3 migration with a default encoding forstrobjects.
(#14)Fix updating records that reference a broken interface
when the interface’s top-level module is missing.Fixed skipping of blob records so that oids in references to blobs
are still converted.Add support for Python 3.8a3.Drop support for Python 3.4.1.1 (2018-10-05)Skip records for ZODB.blob when migrating database to Python 3 to not break
references to blobfiles.When migrating databases to Python 3, do not fail when converting
attributes containing None.Fix tests on Python 2 with ZODB >= 5.4.0, which now uses pickle
protocol 3.Fixis_brokencheck for old-style class instances.Add support for Python 3.7.Drop PyPy support.1.0 (2018-02-13)Support Python 2.7 and 3.4, 3.5 and 3.6 and pypy 3. Drop any older
version of Python.The option to the select the pickler (--pickler) has been
removed. This was only useful if you had extension classes with
Python 2.5 or less.Added an option to convert a database to Python 3.0.5 (2010-10-07)More debug logging shows now the currently processed OID
(that is helpful to determine which object misses the factory).Support for missing factories have been improved: an error used to
occur if a pickle needed an update and contained a reference to a
missing class (not instance of this class). This case is now fixed.Python 2.4 is no longer supported. Please stick to version 0.3 if
you need Python 2.4 support.0.4 (2010-07-14)Add an option to debug broken records.Add an option to skip records.Add an option to use Python unPickler instead of C one. This let you
debug records. As well Python unPickler let you update old ExtensionClass
records who had a special hack in the past.Broken interfaces are well supported now (if you did alsoProvides with them).0.3 (2010-02-02)Unplickle and re-pickle the code to rename references to moved classes.
This make the script works on database created with older versions of
ZODB.If you are working directly with a FileStorage, POSKeyError are reported
but non-fatal.Remove superfluous code that tried to prevent commits when no changes
happened: ZODB does this all by itself already.0.2 (2009-06-23)Add option to store the rename rules into a file.Don’t commit transactions that have no changes.Load rename rules from entry pointszodbupdate.Compatibility with Python 2.4Rename fromzodbupgradetozodbupdate.Add ‘verbose’ option.Improve logging.Suppress duplicate log messages (e.g. if the same class is missing in
multiple objects).Improve the updating process: rewrite pickle opcodes instead of blindly
touching a class. This also allows updating pickles that can’t be unpickled
due to missing classes.0.1 (2009-06-08)First release.