[ZODB-Dev] ZEO and blobs: missing tmp file breaks transaction on retry

[Jim Fulton]

On Thu, Nov 12, 2009 at 6:24 AM, Mikko Ohtamaa <mikko at redinnovation.com> wrote:
> Hi,
> We am trying to use BLOBs with ZODB 3.8.4 and ZEO to store images on content
> objects using plone.app.namedfile.
> We started having more or less random serious issues which break the site.
> It looks like that for logged in users, for some page loads, BLOBs are being
> rewritten on every request. Somehow transaction is being retried and retry
> fails due to missing .tmp file. This is probably fault on our code, but in
> any case ZEO/ZODB utterly fails causing nasty exceptions.
> (Since I am not a ZODB expert every stated above might be completely false)
> Here is the detailed document of the
> issue: http://code.google.com/p/dexterity/issues/detail?id=94&colspec=ID%20Type%20Status%20Priority%20Difficulty%20Milestone%20Owner%20Summary
> I hope to find advice
> 1) How to debug ZEO - this was not particularly
> encouraging: http://plone.org/documentation/tutorial/debugging-tips-and-tricks-a-real-life-example/oh-server-where-art-thou
> 2) The actual solution to the problem
> 3) What might cause it

I suggest trying to use ZODB 3.9.3 instead. I consider blob support in
3.8 to be somewhat experimental.

Jim

-- 
Jim Fulton