Christopher E. Brown:
> On Mon, 23 Jul 2007, Wietse Venema wrote:
>
> > Christopher E. Brown:
> > > True MailDir, and the extented Maildir+ are NFS clean.
> >
> > What happens with non-idempotent requests, such as:
> > - client requests link(tmp, new)
> > - server reply is lost
> > - server crashes and loses the request ID cache.
> > - client times out
> > - client requests link(tmp, new) (retransmission)
> > - server replies with error (file exists)
>
>
> Maybe I am missing somthing here, please fill me in if I am. I can think
> of corner cases where this could cause duplicate messages.
>
> It is not ideal, but better than losing the message. Also, while this
> would seem to me more likely to happen over NFS (timing less critical,
> larger window), I would think that a system crash at the wrong moment
> could trigger the same issue on most any filesystem.
This is not a problem with LOCAL file systems (if the machine
crashes, then Postfix dies with it; transaction is not completed,
and the client remote SMTP client retransmits the messae some time
later).
Wietse
> The only way around this would require a stateful filesystem that the
> application was fully aware of and that the mailspool format/procedures
> were designed to work with.
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