Thinking about the symptoms from a software engineer / sysadmin

Hopefully Yahoo have designed their system so that a fault duplicates
rather than skips a given message when a machine goes down part way through
sending out a batch. That's how I would have de signed it too.

It is irritating to get the same message twice but not anywhere as bad as
finding out you totally missed one

It does not make sense to do a full transaction handling style "commit"
after each email so if anything fails during a batch, that whole batch gets
send again and those lucky enough to be at the top of the list get
duplicates, those lower down the list don't.

If so what we are seeing is the effect of a sensible design decision,
triggered by whatever issue is currently making their servers unreliable

Their servers do seem to be unreliable at present.

MY guesses include
- venerable/unmaintained software,
- overload with increasing usage,
- overload due to increased hacking attempts,
- overload due to increased security software in response to fears of
increased attack surfaces as new threats are understood
- overload escalation (ie as any of the above takes out one server the
others get a bigger load while the failed one reboots and that makes
another one more likely to go down just after picking up the work that was

Those are all guesses: afaik Yahoo has not commented on this yet.

In my opinion the fact that some of us are seeing >2 copies of some emails
implies that overload escalation is compounding whatever the original
problem is.  But that is just a guess built on guesses...

(If you were my line management I would be using words like "tentative
conjecture" "working hypothesis" "potential causes to eliminate from our
troubleshooting" rather than "guess". Luckily this issue is not my problem)


On Thu, 9 Aug 2018, 20:34 Helen Borrie
[firebird-support], <> wrote:

> Tomasz wrote:
> > I know it's off-topic, but does anyone else experience receiving
> > multiple copies of some posts on this list, or is it just me?
> > Sometimes I have 2, 3 or 4 identical copies in my inbox (like Hugo's
> > from yesterday - 2 copies). They seem identical except for their X-UIDL,
> > but AFAIK UIDLs are being assigned by the receving e-mail server, so
> > that doesn't prove anything.
> > Sorry to bother you with this, maybe someone just clicks "send" with a
> > shaky hand, but maybe my mailbox is messed up. No duplicates from other
> > lists, though.
> I've been seeing the same thing in this and other Yahoo lists.
> Also, as list admin, some other behaviour, such as getting a 404 error
> when I click through the supplied link to a post that requires
> moderation. The latter problem went on for a week but it seems to
> have been resolved now. I wonder whether Mark saw the same thing with
> the Firebird-Java list.
> Yahoo recently underwent an ownership change: it belongs to Verisign
> now. I concluded that our list problems were probably due to new
> hands on old software as the Verisign people gradually move the Groups
> archives to their own servers. There's also the activities of
> U.S.-based list providers having to become compliant with the EU
> privacy laws by the July 30 deadline. It's probably a mix of
> circumstances.
> Helen
> ---
> This email has been checked for viruses by AVG.
  • [firebird-... Tomasz Tyrakowski [firebird-support]
    • Re: [... James Woodard [firebird-support]
      • R... Tomasz Tyrakowski [firebird-support]
    • Re: [... Mark Rotteveel [firebird-support]
      • R... Mark Rotteveel [firebird-support]
    • Re: [... Helen Borrie [firebird-support]
      • R... 'River~~' [firebird-support]
      • R... Mark Rotteveel [firebird-support]

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