'HTTP TIMEOUT (77)' and no mirror entry

[stevie]

Snipe placed for item 131540477706, but it seems no bid was made. 'Gixen Main - Chicago' shows 'HTTP TIMEOUT (77)', and 'Gixen Mirror - Miami' shows no entries at all. I am a paying subscriber.

I realise that there have been problems today with an outage of one of the servers for two hours, but surely the mirror should have bid anyway - that's the sort of reliability that I subscribe to the pay-for service for.

Any ideas what went wrong, and whether this might happen again?

[Cupid]

Was this snipe part of a Group?

That would explain it, since snipes in Groups are never Mirrored.
_________________
Mark

[stevie]

> Was this snipe part of a Group?

Yes.

> That would explain it, since snipes in Groups are never Mirrored.

Thanks for the explanation - useful. So if you only ever bid in groups, you gain nothing by subscribing - ouch.

[Cupid]

Group snipes, by definition, are replaceable by each other... so you would gain less by having such snipes Mirrored, even if the interconnection between them were technical possible to implement on two servers.

There are other advantages of a Mirror subscription, like variable offsets, multi-win groups etc. that you can still take advantage of, even if you only ever set up Grouped snipes.
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Mark

[Gixen]

[stevie]

Sorry to say, but this makes no sense to me:

> Group snipes, by definition, are replaceable by each other...
> so you would gain less by having such snipes Mirrored,

I imagine I am bidding for a couple of splungecrockets, one of which comes up today and the other comes up tomorrow. I only want one splungecrocket, so I put them in a group, so that if the first one wins the second one is cancelled, but if the first one is outbid then gixen goes on to bid on the next one for me tomorrow.

Now, at this point, if they are not mirrored, it means that I am one HTTP TIMEOUT away from my bid failing -as happened to me earlier in the week. But if they are mirrored, it means that even if one server encounters a HTTP timeout error, there is a very good chance that the other server's bid will complete anyway and so I still get to bid.

So with mirroring, I gain, because my snipe is more likely to happen. And I see nothing that is worse (not a gain) by having mirroring. If it's mirrored, my chances of the snipe happening are much higher than if it's not mirrored. What's not to like? I cannot see how it is that I would gain less (than what?) by having my grouped snipes mirrored.

Perhaps I missed something - please do let me know if so, preferably with examples.

Thanks.

[Cupid]

Sorry if my post was not clear... I did not mean to imply that Mirroring of Grouped snipes would not be an advantage... just that it is not as essential as for non Grouped snipes (that is what I mean by 'gain less' i.e. you don't gain as much), since you have other chances to win the thing you want.

I was also trying to say that with two servers, bidding independently, it would be technically a great deal more difficult to have later snipes cancelled when you do win an auction... since both servers would then need to cancel those snipes and the win may happen via a bid from either... This is the reason Mario decided to specifically exclude Grouped snipes from the Mirror implementation.

It is a feature of the implementation that the servers act independently of each other when placing bids... any interaction between them at that stage would decrease the overall reliability due to the greater coupling of processes.
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Mark

[TIO200]

WHAT happened to the system over the weekend> I had over 45 bids on ebay and all I received was HTTP timeout or nothing at all ! many of the bids that others won were less than what I had placed. I lost out on so many Nothing is perfect, but I will not be using this system for at least a month after this, I though they could solve the non attending problem, but apparently not ! you snooze.. you loose !

[Cupid]

TIO200,

Please note that the Main facility suffered from some unscheduled down time over the weekend:

http://www.gixen.com/forum/viewtopic.php?t=7373

I assume your snipes were not Mirrored?

If they expired during the down time then that would account for their failure.
_________________
Mark

[stevie]

Cupid, I don't accept your reply. If the servers can coordinate with each other to schedule bids (i.e. one says to the other, "you need to bid on this"), they can coordinate to cancel scheduled bids (i.e. one says to the other, "you don't need to bid on this one any more"). It wouldn't make it less reliable.

You don't want to do it - that I get. I'll be more cautious about using Gixen grouping in future, and if I find a service that does offer grouping and resilience, maybe I'll give that a go for a while and see how I get on.

[Cupid]

stevie,

It isn't a matter of my not wanting to do it... I don't develop it at all... Mario does, I am just a user like yourself, albeit one with some experience of development and support of similar IT projects.

The fact is though that scheduling snipes on two servers is a very different process from automated cancellation between two servers each of which is independently tasked with placing bids. Especially when you consider that snipes may already be in flight when they require cancellation... it isn't as simple as a deletion from a database... like just being the opposite of adding one (which, if it happens to be too late, just doesn't get executed, as already highlighted extensively on the site)... The cancellation requests would have to flow both ways and confirmations then sent and received both ways also. Any wait for response between the two servers couples them... and if one goes down that affects the other... there IS less reliability in that scenario.

The whole point of having two servers working for you is that if one has issues the other works for you.. if you make one stop, or even just run less efficiently/slower, when the other has a problem then you pretty much defeat the point of having them both.

I postulated a solution many years ago... when I pointed out that the method Gixen uses to detect the success (in winning) or failure of a snipe by seeing, once the auction is closed, if the actual price is higher than the bid submitted is not the way that I detect whether or not I won an auction... that would be looking in my 'Purchase history' on Ebay... and that could be done independent of the placement of the bid.. then that could be used to decouple the process of cancellation between two servers... but it would slow things down considerably and mean that auctions within a few minutes of each other could never be dependably placed in the same Group without there being a higher risk of both being won... I believe that was considered worse than the current implementation of keeping all Group snipes on the Main server only.
_________________
Mark