[ZODB-Dev] ConflictError and POSKeyError with 2.6 CVS :-(

[Chris Withers]

Toby Dickenson wrote:
> Not precisely, but this is a class of problem that I am particularly 
> interested in. 

As am I, now :-(

> a. Ive had a few of these too, and I scare easy.

I've had 435 of them in the last day. I don't scare easy, and they're all for 
the same OID, but this doesn't look good :-(

> 1. Those two objects are present in the database, but can not be loaded for 
> some short-term reason. If this is a FileStorage then you may get some 
> mileage from shutting down the zeo server, deleting the index file, and 
> restarting. Have you done this since the 2.6 upgrade?

Will try this, I don't remember doing it before...

>     2a. Possibly this was a dangling when the reference was committed. If
>     so, this would be a ZODB bug (or your application code. Do you have 
>     and custom conflict resolution code perhaps?).

I don't have any custom conflict resolution code.

>     We know that there
>     are currently several such bugs, but we believe they only happen in
>     extremely rare circumstances.

What are these circumstances?

>     DirectoryStorage now has code to detect
>     this during the commit; so far I have not trapped anything interesting.

Is DirectoryStorage good for Production use yet? it might be interesting to try 
here and see if I catch anything interesting :-)

>     2b. Possibly the reference was not dangling when it was committed, but
>     FileStorage has incorrectly removed the object that it was referring
>     to (probably during a pack).

Yeah, two out of the three FileStorages served up from this ZSS are packed very 
regularly. We shall see if deleting the index helped...

cheers,

Chris