Subject Re: [firebird-support] Multiple copies of the same post
Author River~~
Post date 2018-08-10T09:54:59Z
Thinking about the symptoms from a software engineer / sysadmin perspective...

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 dropped)

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)

R~~


On Thu, 9 Aug 2018, 20:34 Helen Borrie helebor@... [firebird-support], <firebird-support@yahoogroups.com> 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

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