[Zope] Re: All Of My Zope 2.6 Transactions Since 2/6/07 Are Gone!

[Tres Seaver]

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Mark, Jonathan (Integic) wrote:
> """I know of 2 situations where such things can happen unexpectedly:"""
> 
> Thanks for the assistance. I was able to recover using an XML data
> backup outside of Zope and move the missing content as flat files to the
> Apache document root on a new server. Since I have decided to abandon
> the old machine now I won't bother to investigate why the data disappeared.
> 
> What is the lesson learned? That when you are using an old (2.6.2)
> version of Zope there is an increased likelihood of something bad
> happening.

Strictly speaking, your *first* problem was in running 2.6.*2*, rather
than 2.6.4 (the latest stable release in the 2.6 line).  That one
should've been a "no brainer, just do it" upgrade, with fairly minimal
testing.  The changelogs for 2.6.3 and 2.6.4 contain a large number of
bugfixes, many of which had important security or stability implications.

Upgrading acros *major* versions (from 2.6.x to 2.7.x, for instance) is
potentially much riskier, and should normally require more careful
change management, as the chance that your third-party or custom code
might break during the upgrade is much higher.

For best support from the community, you really need to be running the
latest stable version of a release line which is still in maintenance:
at this point, 2.8.x is just about at EOL, so finding a way to migrate
to 2.9.x soon would be your best bet.  I would advise doing that
"stepwise", moving across one major release line at a time.

> Presumably Zope 2 gets more stable with later versions. So
> use Yum to upgrade Zope 2 regularly.

I can't say for sure what happened in your case:  that you used yum to
upgrade suggsests that you were also running with the RPM-supplied
version of Python.  For the 2.6.x line, that would've been a Python
2.1.3 or 2.1.4:  the "system" verions of those Python's on RH-derived
boxes were not built with large-file support enabled, which might
explain the symptom you saw (rollowver on the 2Gb file size limit).

Python 2.2 and later built with LFS enabled by default on almost all
platforms, and thus would not have been subject to the "wraparound".

Thus, most "old hands" never run with the '/usr/bin/python' supplied by
their distribution for production Zope use, but rather build a separate
Python which is used only to run Zope.


Tres.
- --
===================================================================
Tres Seaver          +1 540-429-0999          tseaver at palladion.com
Palladion Software   "Excellence by Design"    http://palladion.com
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