Simultaneous Submit to overcome Z1 inventory
Feb 22, 2019, 3:05 pm
#1
Original Poster
Join Date: Feb 2000
Posts: 6,535
Simultaneous Submit to overcome Z1 inventory
Trying to get two seats at cheapest J pricing with Z1 inventory.
Anyone have experience with ticketing one in each of two browsers with simulatenous submit?
DL.com and Expedia (via AMEX).
Anyone have experience with ticketing one in each of two browsers with simulatenous submit?
DL.com and Expedia (via AMEX).
Feb 22, 2019, 3:16 pm
#2
Join Date: Oct 2012
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Posts: 1,003
It won't work. One seat in Z = one seat in Z. You cannot magically make another Z seat appear with this trick...
Whichever browser is second to the finish line will most likely error out with the webpage displaying the fare has gone up.
Whichever browser is second to the finish line will most likely error out with the webpage displaying the fare has gone up.
Feb 22, 2019, 7:52 pm
#4
Join Date: Jun 2009
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i had a similar issue happen before but I wasn't trying to simultaneously book. I guess I was just the slower of the two people. I called Delta up and they honored the price I was originally quoted. But ymmv
Feb 22, 2019, 8:08 pm
#5
Join Date: Nov 2006
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I can't say too much, but having intimate knowledge of how the reservation code works, this is impossible. The inventory column is briefly locked while a reservation is made. First one in wins.
Feb 23, 2019, 4:16 am
#9
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I'm interested in that mechanism. I have found itineraries (non-stop, so it's not a married segment thing) found by ITA Matrix that did not find inventory on delta.com or aa.com. But Orbitz has been able to ticket them at the ITA Matrix price, and tickets were honored for travel.
Last edited by 3Cforme; Feb 23, 2019 at 5:49 am
Feb 23, 2019, 4:31 am
#10
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I don't think you have to worry about disclosing proprietary information here, this is how any well written inventory management system (and any ACID compliant database system) will work. When attempting to update inventory, a write lock must be obtained on the inventory counter (and only one request can hold a write lock at any given time), then the value of the counter is verified (this is where Z might now = 0 if an almost simultaneous sale were to take place), then the value of the counter is updated, then the write lock is released and the sale processed.
Feb 23, 2019, 4:36 am
#11
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I'm interested in that mechanism. I have found itineraries (non-stop, so it's not a married segment thing) found by ITA Matrix that did not found inventory on delta.com or aa.com. But Orbitz has been able to ticket them at the ITA Matrix price, and tickets were honored for travel.
Last edited by bennos; Feb 23, 2019 at 4:55 am
Feb 23, 2019, 5:42 am
#12
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There's a difference between searching for available inventory and booking it once found. It's entirely plausible that ITA has better searching algorithms than the airline websites (airline inventory searches are a notoriously difficult computational problem to solve), or that caches got in the way, or that the website had a bug, or that the website implemented a different search algorithm, etc. If for whatever reason the search doesn't find existing inventory then the frontend has no way to know to ask to book it.
Of course, another time in the last few weeks I was also able to find a fare on Matrix and the agent was able to see it as well, so there was probably just a gremlin in the system.
Feb 23, 2019, 5:57 am
#13
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There's a difference between searching for available inventory and booking it once found. It's entirely plausible that ITA has better searching algorithms than the airline websites (airline inventory searches are a notoriously difficult computational problem to solve), or that caches got in the way, or that the website had a bug, or that the website implemented a different search algorithm, etc. If for whatever reason the search doesn't find existing inventory then the frontend has no way to know to ask to book it.
Last edited by 3Cforme; Feb 23, 2019 at 6:17 am
Feb 23, 2019, 6:12 am
#14
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Some of these systems use somewhat outdated information for the search and then only verify real time inventory availability during the purchase step. This is why one sometimes sees the message that the fare is no longer available after it appears during a search. The alternative of setting aside inventory during the search would be less desirable, although I see this happening on other types of websites that sell restricted inventory and tell you that it's being held for you for a certain period of time. Starriott Bonvoy shows the time remaining, although apparently doesn't pull the inventory until you go past the search phase and begin to book the room. Eventbrite appears to set aside the tickets at an earlier stage (again showing you have much time you have to complete the transaction), although typically on that website there's no search and consider step as one goes there to purchase a ticket to some particular event.
In the famous "fraudulent" ticketing case of the AA elite who did searches to check likely upgrade availability. It was claimed that AA sets aside inventory and creates a PNR at a much earlier phase than other airline websites generally do.
In the famous "fraudulent" ticketing case of the AA elite who did searches to check likely upgrade availability. It was claimed that AA sets aside inventory and creates a PNR at a much earlier phase than other airline websites generally do.
Feb 23, 2019, 6:58 am
#15
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There is no such thing as simultaneous submit in systems. Central database process requests sequentially, even if just by 1/1000000 of a second.
