[citrin_ru]

> Many people don't even have cash anymore, either in their wallet or at home.

Even if you have cash many shops would not sell anything in case of a mass outage because registers are just clients which depend on a cloud to register a transaction. Not reliable but cheap when it works.

[bill3478]

Many supermarket chains (in the West at least) have satellite links at their major locations because they can't afford to close a store just because the local ISP had an issue.

The real question is how long can some of the smaller banks' datacenters stay up.

[inkyoto]

Firstly and most importantly, a cash register needs a power outlet. It is highly contestable that every single Western supermarket out there has a diesel generator down in the back / storage room that will kick in in an instant if a power outage begins.

Lest also forget the Crowdstrike drama where many supermarkets simply went dark, in some instances for nearly 24 hours, despite working communication links. But I digress.

[SchemaLoad]

Crowdstrike was an interesting one. Just as it was going down I went out to the supermarket and found half of the self checkouts had bluescreened. Then a few hours later they were all back and functioning again. The supermarket had remote management at a level below the OS that could restore the whole countries self checkouts rapidly.

[crote]

I would not be surprised if they simply booted an image from the network. It would significantly simplify maintenance, as for any change you'd just need to update a single image and push it downstream to an in-store management server. The individual terminals essentially become disposable.

[bell-cot]

> It is highly contestable that every single Western supermarket out there has a diesel generator down in the back / storage room that will kick in in an instant if a power outage begins.

Literally true. However:

- If it takes them 10 minutes to fire up the generator, then 5 minutes to restart the network and registers, that is no big issue (in a many-hour outage)

- At least in my part of the USA, many supermarkets do have generators - because storm damage causes local outages relatively often, and they'd lose a lot of money if they couldn't keep their freezers and refrigerators powered. Since the power requirements of the lighting and registers are just (compared to the cooling equipment) a rounding error, those are also on generators.

[IIsi50MHz]

Plus, there are backup-power lories and refrigerated trailers. If your shop doesn't have enough backup power for duration, you might see several of these pull into the carpark all at once. If not all of the chillers can be powered, shop's staff will schlep stuff to the refrigerated lories.

Seen it done in USA, for a Target next to a Kroger grocer. Kroger lost everything that needed cold after reserve either ran out or wouldn't start, but Target had a contingencies contract and lost no product.

[prmoustache]

Well,in my experience it was the case for the 2 largest supermarket chains. We lost electricity at 12:30pm and only got it back during the night at 3am.

But both major supermarkets nearby worked on diesel generators and payment by card worked flawlessly. I guess they had satellite connection.

It might have been more complicated in small villages but people living in rural areas ually still use a lot of cash.

[swiftcoder]

In my local area of Spain/portugal, 2/3 supermarkets and 2/3 gas stations had generators up and running within a couple of hours. We’re pretty rural, though - I don’t know that urban areas faired as well

[diggan]

We're outside Mataro, had to make a trip into Barcelona yesterday. I'd say most gas stations north of Barcelona/Maresme area were 100% offline, some (we found only two, from 6 visited) gas stations still had operational pumps but huge queues and cash only. None of the TPVs seemed to work anywhere in the afternoon yesterday here, even the battery powered/mobile network ones.

[ricardobayes]

That's true, I went shopping cca. 4-5 hours after the blackout started and had no issues, even card transactions worked. Whoever designed the retailer, they clearly had this scenario in mind. Even the "self-service" computer kiosks all worked.

[brewdad]

In a multi-day event like we are talking about here, couldn't a shop owner revert to a paper ledger? I mean, it would suck and transactions would take much longer but if the alternative is people starving or having your inventory looted by a desperate mob, a nineteenth century solution seems preferable.

[ryoshu]

They can and do. They will also do deep cuts on prices/give away for free for refrigerated and frozen goods because those will just get tossed and neighborhood goodwill is still a thing in some places.

[chihuahua]

There was a 4-day power outage here (Seattle suburbs) last fall, and one of the auto parts store made an effort to serve customers even though they didn't have any power. I paid cash, and I forget whether or how they did credit card transactions (possibly by writing down CC numbers on paper.) They made a lot of phone calls to a different store to get prices for items.

[spiddy]

I'm located in Barcelona, and yesterday lot of transactions on mini markets / pharmacies were not possible because the item prices were unknown, adding to the fact there was no phone lines available to reach out.

[miki123211]

And in many places in Europe, registers are literally required by the government to be this way, for VAT fraud avoidance reasons.

[ricardobayes]

It's probably just Hungary though, I don't know of any other country mandating an always-online cash register.

[pta2002]

Portugal has mandatory electronic receipts. By this I don't mean email receipts, I mean that all receipts have a code on them that is then also available to be looked up on the government's side (e-Fatura is the app for this) for tax reasons. I think it's fairly simple though, just registers the total amount, the seller, and how much VAT was paid.

However I assume this can work offline with the data being uploaded later though, as basically all the small supermarkets and shops were still open here (_incredibly_ chaotic though), and on the big supermarkets card payments were working (TBF, even the free wifi was working there, I guess they probably have some satellite connection).

[the_duke]

It's an EU regulation.