[ZODB-Dev] tid error with ClientStorage cache in Zope 2.9.2

Chris Withers chris at simplistix.co.uk
Mon May 1 06:34:44 EDT 2006


Tim Peters wrote:
> it knew about.  To support this, a persistent ZEO cache stores the
> value of the largest tid the ZEO client knew about in the cache file.

Hmmm, didn't think I was using a persistent client cache here...

...well, there are .zec files in the var directory, so I guess I must 
be. What controls whether a persistent or temporary client cache is used?

>> In a perfect world, we could change it and see what tests fail.
>> I'm not that brave ;-)
> 
> Then shame someone else into courage ;-)  I'll bet a dollar no test will 
> fail.

Well, that's what I'm scared of ;-) I _want_ to see tests fail if this 
changes, otherwise it means it's all untested and even more scary...

So, Tim, how do I shame you into having the courage? would beer help? 
*grinz*

> That's comparing a pre-MVCC ZODB to a post-MVCC ZODB, 

Yeah, I know :-S

> client cache has little in common between them.  The pre-MVCC ZEO
> client cache did no sanity checking on the "last tid" values it saw
> over time, so this particular error was impossible in Zope 2.7 -- even
> if tids were so pathological that they got smaller over time, a Zope
> 2.7 ZEO client cache wouldn't complain about that.  A post-MVCC cache
> may well complain even if nothing is wrong :-)

frying pans and fires ;-)

What do you recommend as a course of action?

Chris

-- 
Simplistix - Content Management, Zope & Python Consulting
            - http://www.simplistix.co.uk


More information about the ZODB-Dev mailing list