skysight-inc/HackerNews huggingface dataset:
> Third party apps are not allowed by airlines to charge less than the airline

How come I regularly see third-party OTAs offer the same itineraries cheaper than the airline then?

Sometimes there's a mystery fee added just before payment, but not nearly always – and I've flown such itineraries once or twice myself (if the difference was significant and I was absolutely certain I wouldn't need any change or extra service).

I was under the impression that these effectively share part of their agent fee with the traveler as a form of kickback (to appear as the cheapest option in search, which in the end might end up a win-win for both).
Here is my understanding, roughly:

- say you need a messaging system to communicate between different components
- that messaging system is a 3rd party library or tool, it has no knowledge of your needs or architecture
- therefore it can have no knowledge of what counts as a duplicate message, it either just blasts your message off once, or blasts them off until it gets an ack, it is up to the software you build around this component to avoid duplicate processing
- so yes of course you can build "exactly once processing" on top of an "at least once delivery" system
- but it still makes sense to talk about the distinction between delivery and processing, and "exactly once delivery is impossible" is still (in OP's terms) a "useful" claim

I haven't personally used kafka but it and similar systems (I vaguely recall some work by Pat Helland that may fall into a similar bucket) could possibly be said to a) constitute messaging systems, b) provide exactly once delivery semantics, in that they are
less of a library and more of a framework that provide a concept of "duplicate message" that you basically buy into by using those systems.

You could then argue that "if it provides exactly once delivery it is not a messaging system", maybe there's a good argument there or maybe it's just pedantry.
And uploads.
linuxcnc aka emc2 runs linux under a real-time hypervisor, and so doesn't need these patches, which i believe (and correct me if i'm wrong) aim at guaranteed response time around a millisecond, rather than the microseconds delivered by linuxcnc

(disclaimer: i've never run linuxcnc)

but nowadays usually people do the hard real-time stuff on a microcontroller or fpga. amd64 processors have gotten worse and worse at hard-real-time stuff over the last 30 years, they don't come with parallel ports anymore (or any gpios), and microcontrollers have gotten much faster, much bigger, much easier to program and debug, and much cheaper. even fpgas have gotten cheaper and easier

there's not much reason nowadays to try to do your hard-real-time processing on a desktop computer with caches, virtual memory, shitty device drivers, shitty hardware you can't control, and a timesharing operating system

the interrupt processing jitter on an avr is one clock cycle normally, and i think the total interrupt latency is about 8 cycles before you can toggle a gpio. that's a guaranteed response time around 500 nanoseconds if you clock it at 16 megahertz. you are never going to get close to that with a userland process on linux, or probably anything on an amd64 cpu, and nowadays avr is a slow microcontroller. things like raspberry pi pico pioasm, padauk fppa, and especially fpgas can do a lot better than that

(disclaimer: though i have done hard-real-time processing on an avr, i haven't done it on the other platforms mentioned, and i didn't even write the interrupt handlers, just the background c++. i did have to debug with an oscilloscope though)
Same understanding:
On the receiver side, we are going to drop duplicates (by processing, or by having no effect on the grass cutting any more). Thus, the end user is then seeing only one effect, one message delivered.
The effect of delivery "message received" or "grass is cut" is achieved.

But still, the sender might need to send more than once (until confirmation). From the cost at the sender "sending multiple packages" or "sending more grass cutters" this is still the scenario "send one or more".

Sorry to fuel the fire... it is about the definition of "delivery"
You apparently missed this:

"Just for the sake of completeness I should point out that removing duplicates at the receiver is a pretty extreme oversimplification of what you would do in practice to provide exactly-once delivery. A complete solution would almost certainly be an example of Greenspun's Tenth Law applied to the TCP protocol rather than Common Lisp."
Don’t use technical terms like “exactly-once delivery” if you don’t have want it to be interrupted as technical
The misinformation and regulation dodging is happening right now, and the functioning Brazilian government is taking steps to stop it. So we should just be happy with the small win as a citizens of the world.

> If [politican you don't like] had the power to consider his misinformation to be truthful and truthful information to be misinformation would you still be in support of this?

If an evil person is trying to rewrite reality from their position of power, you'd hope the checks and balances in the government prevent them from doing so. While the Brazilian government can stop misinformation from spreading, they can also allow real information to continue to spread.

But if we go down this reductive doomsday scenario all the way to the bottom, where there are evil people stacked from top to bottom, your nation failed a long time ago. And maybe part of the blame sits on the people preaching do-nothingness and requiring a perfect system of laws and governance before taking action.
I worked on this for tripstack a while ago. They offer it through their partners. Kiwi is the other one who made it a thing. Now it’s more common to see it all over.
> Incorrect, and I'll explain why. Remote work DOES NOT imply anything about how, or where, you have to work.

No, I can assure you it is correct. It DOES imply that I am not guaranteed the thing I want which is to work in an office solely with other people in that office. This is the same that an RTO decree does not guarantee that people will be allowed what they want — which is to work remotely.

Both groups don’t get the thing they want when the company puts them in the situation they don’t like. They’re exactly the same thing.

> Because you personally enjoy working in an office, you believe everyone should be forced to as well at your whim.

Again, no, never said this.

I said that a company deciding that a RTO strategy is best for them is fine. A company choosing to work remotely is fine. But if you dislike the choice your company makes, either learn to live with it or get a new job.

Neither decision is bad. It just depends on which side of the foaming-at-the-mouth aisle you sit.

> Because you personally enjoy working in an office, you believe everyone should be forced to as well at your whim.

Again, this is the same thing as the remote worker believes. Because they enjoy working with other remote workers they believe everyone should be forced to as well at their whim.

> If you disagree, I encourage you to go to the office by yourself. You'll quickly realize you don't care for the office, you care for forcing people to be in the office with you.

I actually work at a 100% remote company and do go to an office everyday (albeit one I rent for myself). Have been doing it since 2021.
Doesn't have pornhub or Brazzers, not even logo SVG archiving escapes the tentacles of the moral police (keep in mind pornhub it's one of the top 10 most visited sites in the world)
> The Taliban offer to hand over bin Laden and George W. Bush refuses

A bit disingenuous to say that and leave out that the most generous version of that offer was to hand Bin Laden over to a third country.
Zipline Might Pull Off Drone Delivery [video]
You apparently missed this part:

"Just for the sake of completeness I should point out that removing duplicates at the receiver is a pretty extreme oversimplification of what you would do in practice to provide exactly-once delivery. A complete solution would almost certainly be an example of Greenspun's Tenth Law applied to the TCP protocol rather than Common Lisp."
As explained in the answer, almost always Expedia will issue a single ticket across one or more airlines (the technical term for that is "interlining"), which is different from an itinerary made up of actually separately issued tickets.

In the former case, there's always exactly one airline responsible for getting you to your destination in case of a missed connection or itinerary changes; in the latter case, you're often on your own.
That's something you can vetify yourself though. What if the government claimed that Polish soldiers attacked the German border, you claimed that it was actually German soldiers in Polish uniforms to give Germany a casus belli to invade, and a court censored your claim because they insist it's misinformation? How the hell is the average citizen going to determine what is misinformation or not there if any counterarguments or evidence are censored?

https://en.m.wikipedia.org/wiki/Gleiwitz_incident

I have a hard time believing you're this naive about this. Either you really haven't thought through the repercussions, or you're in favor of it because it's being used against your political enemies (for now).
> TCP-over-TCP

> It lowers the throughput due to more overhead and increases the latency. On connections with packet loss or high latencies (e.x. satellite) it can cause a TCP meltdown.

This actually isn't a problem with SSH tunnels unless you're using TAP/TUN, because It unpacks and forwards the TCP streams. But you can still get reduced performance with multiple channels due to head of line blocking.
Same dream here - they work very interesting problems at very interesting scale, but I can see 3-4x the comp while working from anywhere? Not even a chance. I do sometimes fantasize about making a career shift when the cash comp isn't that important to me and the kids are out of the house, but as of now I value afternoon coffee breaks with my kids just too darn much.
One search feature I wanted was a way to look up a list of all flights leaving an airport on a certain day.

In the early stages of vacation planning, it’s be fun to see a list of all possible direct flights to evaluate my options, but the use case of doing flight searches with an unknown destination isn’t too common. Basically, i want to be able to browse flights like a bus schedule and just see what the possibilities are from a particular start point
How 'bout 0%? I have zero compassion with displaced Palestinians - they were wronged, but what they did after was so much wronger.

We both know how Palestinians repaid those who was kind to them- by Lebanon Civil War and Black September. Israel was ready to cede what it won in defensive wars, they got out of Gaza, built infrastructure and invested in businesses to provide jobs.

Palestinians had countless opportunities to make peace and live a better life. They choose war every single time, made Dalal Mughrabi their hero, dug up water pipes and made missiles out of them.
The leading response does a good job calling out that this is pretty risky for the traveller. Similar to skip lagging, if anything goes wrong you can end up is a pretty difficult position.
Yea... this is kinda inflammatory but I honestly have to agree with it.

The post largely summarizes as "you can have exactly-once delivery if you re-define it to be at-least-once processing with idempotency".

Those are different things.

In fact, that's the entire point behind saying that it's impossible.

You can't design a system that is exactly-once at any level, so don't even bother trying. If someone wants you to guarantee something will happen, you can point to that impossibility to say "you need to retry, it's not optional, and anyone who tells you otherwise is lying to you". That has happened to me multiple times in my career; it's a thing charlatans keep trying to sell to businesses, and businesses eat it up because it sounds so much magically simpler than what their engineers keep telling them needs to be done.

Because it is magic. It doesn't exist.
The end of an era. Good Pivotal Labs, was nice working there.
SSH tunnels are an excellent tool, but nowadays you often want TLS and reverse proxy functionality built in. I maintain a list of such tools here: https://github.com/anderspitman/awesome-tunneling
> No actually, despite all their massive propaganda drives, the Nazis never won through elections.

a Nazi-DNVP coalition did, in fact, secure a majority in the snap elections called immediately after the one in which the Hitler-led Nazi-DNVP minority coalition came to power, and it wasn't until after they did the Hitler established totalitarian control.

(Of course, winning the largest share of seats, and forming a minority coalition because no group of other parties can form a majority coalition and you are able to secure the support of the elected head of state is also winning through elections, even if it isn't a commanding mandate. Systems of choosing a government by elections that can have ambiguous results usually have a set of methods of resolving them, and securing the position in the election from which to emergy victorious from the ambiguous-results-resolution system is still winning through elections.)
>a simple matter of keeping track of all the delivered messages and removing duplicates

Ron, if you have received duplicate messages then by definition you have been delivered that message more than once.

I don't have a PhD in computer science so maybe you can explain how this constitutes "exactly once".
If you ask engineers who work for Tesla to review the Tesla Cyber Truck, they will tell you it's genius and amazing in every way because they don't want to get fired and they are likely also Tesla shareholders.

If you ask engineers who work for Toyota about the Tesla cyber truck, they have the expertise to identify all of the problems with the design and they are not going to get fired for telling you the truth.

Who would you rather listen to? It is the same situation when we are talking about Western journalists vs. Arab journalists.
They can; this usually shows up with a remark of "separate tickets".

There are considerable caveats when doing that – it's generally not advisable for connecting flights (you're essentially on the hook for missed connections etc.), and even just for separate outbound and return tickets it can mean trouble (e.g. if the outbound flight is cancelled, there is no obligation for the separate ticket to be refunded to you).
I absolutely would. I'm sure there are dozens of us. Dozens!
It seems like this person does not understand what exactly once delivery actually means. It's not about being able to do something exactly once if the author is reading this...
A rare example of actual consequences for not following the spirit of the law, but only the letter of it
Here's a good explanation of how the Brazilian Supreme Court did a creative and novel interpretation of the law to give itself powers to investigate and regulate the internet without law enforcement or legislative/executive involvent.

https://news.ycombinator.com/item?id=39966382

That's not enforcing the law.

As documented by the New York Times, the first thing the judge did after getting powers to censor was to call a Brazilian magazine article about the person that gave him those powers 'fake news' and got it removed. It later turned out that article was true so he had egg on his face and had to retract his censorship order.

> To run the investigation, Mr. Toffoli tapped Mr. Moraes, 53, an intense former federal justice minister and constitutional law professor who had joined the court in 2017.

> In his first action, Mr. Moraes ordered a Brazilian magazine, Crusoé, to remove an online article that showed links between Mr. Toffoli and a corruption investigation. Mr. Moraes called it “fake news.”

> Mr. Moraes later lifted the order after legal documents proved the article was accurate.

https://archive.is/plQFT
National Police Index
> The short version is: 9/11 happens. The Taliban offer to hand over bin Laden and George W. Bush refuses [1]

I looked at your link. It seems you missed a huge asterisk on that from your own article:

> the third most powerful figure in the ruling Taliban regime told reporters that the Taliban would require evidence that Bin Laden was behind the September 11 terrorist attacks in the US
I got a mattress last year using Consumer Reports rec for most the mattress with the least synthetic chemicals. I am not going to say its name lest it look like I am shilling for them. I will say, it has been great.
Its not that they won't work out, it's that uncertainty at the time of the decision justifies it. Some then get lucky and others dont and most land in between. You did the best you could given the information at the time. There is then nothing to regret.
Oh, Judge Moraes said it's misinformation, so clearly it must actually be misinformation! Thank you so much for clearing that up!
I just wanted to say, I enjoyed the little pixel art cat that runs towards wherever you click immensely. It’s one of those fun, whimsical little touches that I don’t see all that often. A reminder that the internet can be a fun, whimsical place if we want it to be :)
The problem is, you're using strong language like "under any reasonable definition of 'delivery'." But everyone else is defining delivery differently than you, referring to the delivery of the message to the system itself. Your language implies everyone else is unreasonable.

When your argument depends upon everyone else being unreasonable, maybe you're the one being unreasonable.

Yes, we can make the processing that occurs in response to those delivered message(s) idempotent. But in the end, the system has to either deal with:

1. messages being delivered once or lost entirely, or

2. messages being delivered once or multiple times

You are over-explaining a way to deal with situation #2 (detect duplicates at the endpoint).
while researching, i saw some data being sent over to the server, like this query everytime you visit a site

I'm not surprised in the least --- basically the vast majority of software these days is spyware. Looking at Arc's privacy page, it appears to be mainly marketing fluff similar to what I've seen from other companies. I have yet to find a privacy policy that says frankly "we only know your IP and time you downloaded the software, for the few weeks before the server logs are overwritten."
Your proposed definition of "delivery" is absurd.

If you have duplicate things, then you've clearly been delivered more than one thing. There is no way to deliver something exactly once, and yet the receiver has more than one thing such that they can throw all but one thing away.

It's okay to admit you were mistaken.
It is hard to make the point that "exactly-once delivery" is not a technical term without referring to it. If you think it is a technical term, would you kindly point me to a definition? I'm particularly interested in learning how "exactly-once delivery" is distinguished from "exactly-once processing".
They don't claim that NSA found Bin Laden. They say that they were part of a multi-agency effort that took 9 years to find him. And they say that human intelligence led them to who the courier was.
May I ask why you use search engine for buying something like a mattress or refrigerator? I dont mean to sound that as an insult. I'm genuinely curious. I or anyone I know of will just go to a nearby store and checkout these items to buy. For things like these one would already know who sells these items, even online. So why not directly checkout those stores, either online or physical?
> referring to the delivery of the message to the system itself

And how do you define "the system itself"?
When we get to where you're talking about, I think it'll still be easy to find someone who's not satisfied.

Software and technology in general have been reducing and creating bullshit in varying proportions since the start. People a hundred years ago weren't worrying about the hassle of booking a flight to Shanghai because it wasn't possible.
Anyone other than me get the vibe of Isaac Asimov's classic https://en.wikipedia.org/wiki/The_Feeling_of_Power from such posts?
I can vouch for reading a few history books makes it easy to distinguish them from a pseudo-history book written by an activist pushing an agenda.

Reading reviews of the books helps a lot in finding one worth the time reading, as well as looking at lists and reviews of what other books they've written.

Reading multiple books of the same event gives one a lot of perspective, too. I'm currently reading my 4th history book on the D-Day invasion - all quite different.
You could use flightaware.com for this. Just search a date and a departure airport. The caveat is that the list will be fairly large, with a lot of repeats.
The thing that is at the end of the lossy medium. It must tolerate (0 or 1) or (1 or more) things being delivered to it.
Mostly it was for amusement, haha.

I don't disagree with AM radio being a way. I do disagree with saying cars are required to have it though. Instead, we should focus more on advocating people to have a cheap battery operated/crank radio, which are fairly cheap, can be gotten for 10 bucks off amazon[1].

If your relying on AM radio for emergency broadcasts, a car radio is pretty piss poor unless your on a long drive, but most people probably will never head it because they are listening to podcasts, streaming music from their phones, etc.

To reiterate, I am fine with AM being used for emergency broadcasting, I just think requiring cars to have AM radios is silly. Everyone should have in their home and/or in a road side emergency packs with their tire jack, a cheap battery operated AM/FM radio.

[1] https://www.amazon.com/J-166-Transistor-Excellent-Reception-...
I feel for your pain, and I'm interested in paths that overcome the collapse of trust we're going through. I think your question matters a lot, to reach solutions all of us need (and not quit until we find a positive one)
This stuff is studied to hell and back, there is a formalism.

This stuff is practiced at staggering scale and the heuristics and cheat-while-no-one-looks stuff is gamed to within an inch of its life.

There is an acknowledged nexus of the two in the public domain: https://jepsen.io/consistency.
But you sometimes delivered the bytes twice, before getting the receipt, surely?
Airlines own systems are often awful UI and in case of some asian low costers your data is immediately sold to spammers (and they collect as much your data as they can too).

Depends on exact case but if traveling on a budget going with low costers and connections a good third party can be better than an unknown shitty airline's system.

I used Expedia a few years back, got a lower price and could cancel for full refund within a day but they probably don't do that anymore. Kiwi seemed okay. Ctrip now owned by China.