[Zope] ZODB.POSException.ReadConflictError

[Tim Peters]

...

[Tim Peters]
>> Conflict errors are certainly normal, but IIUC the OP is seeing site
>> errors, not just log msgs ...

[Chris McDonough]
> This is true.  I misunderstood the OP inasmuch as I thought he was
> seeing the error message in his event log, which would be normal   It is
> certainly the intent that end users should never see this error message
> in a browser, but it's not a promise as it depends how the developer's
> code is written.  Zope will retry a request three times due to conflict
> errors before it gives up and presents the conflict-caused error to the
> user.

So maybe it's really a Plone question (as in, is Plone doing something
here for member registration that makes read conflicts unusually
likely?); or maybe the OP's box is overburdened, so that transactions
take much longer than "normal" (e.g., too little RAM, whatever); or
...

It would at least be interesting to know how often conflict errors are
just _logged_ (as opposed to surviving long enough to show up to the
end user).