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"Unknown or expired link." - Why?

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Re: "Unknown or expired link." - Why?

#121

Post by [deleted] »

mfjordvald wrote: post #93
pg wrote: post #82

Earlier quoted context omitted.

Your comment is in a sense its own refutation, because the ultimate test of user experience is whether users continue to use the software. Getting user experience right depends on the users. I wouldn't use this technique in an online store. Random online shoppers would be confused by expired links, and you'd lose sales. But HN users aren't confused by them. What HN users care about is the quality of the stuff on the…

I think you underestimate how annoying the issue is. It's one of those things you put up with because of the content, but which are annoying enough that they detract from the site experience. So far I'd rate the user experience of the site around 3/5 and the content 5/5. You don't need to work any more on the content unless it starts dropping!

[deleted]

Re: "Unknown or expired link." - Why?

#122

Post by tptacek »

mfjordvald wrote: post #93
pg wrote: post #82

Earlier quoted context omitted.

Your comment is in a sense its own refutation, because the ultimate test of user experience is whether users continue to use the software. Getting user experience right depends on the users. I wouldn't use this technique in an online store. Random online shoppers would be confused by expired links, and you'd lose sales. But HN users aren't confused by them. What HN users care about is the quality of the stuff on the…

I think you underestimate how annoying the issue is. It's one of those things you put up with because of the content, but which are annoying enough that they detract from the site experience. So far I'd rate the user experience of the site around 3/5 and the content 5/5. You don't need to work any more on the content unless it starts dropping!

I've been here a long time and seen this expired linky thing happen roughly every other week; on a very few occasions it's been an annoyance, but mostly it makes me smile; after reading news.arc, it's a reminder of what a hack HN is.

I could care less if this issue got fixed. I have never once felt, "man, I'd definitely jump to another site if it didn't have this expired linky thing happen".

(Now, politics stories on the front page, on the other hand... I've often wished for a site with as good a crowd as HN but without the politics...)

Re: "Unknown or expired link." - Why?

#123

Post by dilap »

xnxn wrote: post #49
Silhouette wrote: post #18

I've been wondering about this for a long time, but just as a data point if anyone cares, it has reached the point recently that HN is basically unusable for me a lot of the time, and I really am starting to give up on trying and spend more time elsewhere instead. Perhaps one visitor is no great loss -- I'm hardly the personality around here that someone like patio11 is -- but I hope my contribution is constructive,…

Funny, I suspect it's just the opposite. Long-standing regular contributors are unlikely to be put off by the error messages, especially if they're technically knowledgeable and understand why the error is occurring. On the other hand, new users who might not be accustomed to The Way We Do Things Around Here would be more likely to get upset at the superficial inconveniences and leave. It's probably even the case tha…

I'll just throw in a "me too" with the other responders and say this error annoys the dickens out of me -- and I'm a long-time user and a medium-long-time initiate in the knowledge of the error's source (I tracked it down in the source in a fit of pique about 6 months ago after getting the error for the Nth time).

Besides the actual annoyance of the error, what's extra rankling is it is an example of privileging a neat trick over user-experience, which is one of my Least Favorite Things Ever that programmers tend to do.

(As an aside, I am extremely skeptical that increasing rates of this error occurring will help keep the original user community of the site -- it seems equally likely that longtime users will just get fed up and wander off.)

Re: "Unknown or expired link." - Why?

#124

Post by technomancy »

wnight wrote: post #100
pg wrote: post #64

Earlier quoted context omitted.

The problem there is that we switched to a new deliberately slow hashing function for passwords. Edit: I investigated further, and actually you're right, the problem was due to caching. It should be better now because we're not caching for as long. But I will work on making login links not use closures.

Is that specifically to inconvenience someone who would break in, steal your password list, and crack it offline? If not, what was the design goal? If slowing down web login attempts isn't part of it, why not get a dedicated auth server and offload the crypt stuff onto it? And if it is the goal, you could use CPU-friendly sleeps on the front-end to give increasing delays to the repeated guesser.

> Is that specifically to inconvenience someone who would break in, steal your password list, and crack it offline?

Probably: http://codahale.com/how-to-safely-store-a-password/

Hashing functions designed for speed are absolutely the wrong thing for passwords.

Re: "Unknown or expired link." - Why?

#125

Post by akavi »

DiabloD3 wrote: post #112
jgrahamc wrote: post #13

It's an artefact of the way in which news.arc (actually srv.arc) uses functions for links. Here's the key code: (= dead-msg* "\nUnknown or expired link.") (defop-raw x (str req) (w/stdout str (aif (fns* (sym (arg req "fnid"))) (it req) (pr dead-msg*)))) If the fnid (function ID) isn't in the fns* list then you get the dead message. (def flink (f) (string fnurl* "?fnid=" (fnid (fn (req) (prn) (f req))))) In many place…

A website written in Lisp? That is awesome.

It was created by pg. What other language (type) would he have used?

Re: "Unknown or expired link." - Why?

#126

Post by jcitme »

pg wrote: post #98
tptacek wrote: post #77

Earlier quoted context omitted.

What'd you go with, and how much of a pain was it to get working in Arc? I ask because I'd love to be able to make a claim like "even Hacker News, which is written in a Lisp, managed to implement a modern password hash".

We use bcrypt. Rtm did it. I never looked at the code till now; it's about a page of Scheme.

Would you ever release the code so we can look through it?

Re: "Unknown or expired link." - Why?

#127

Post by dasil003 »

gnaritas wrote: post #114
dasil003 wrote: post #73

Earlier quoted context omitted.

Sorry, bad choice of words. I was just shooting from the hip here in response to the parent that suggests you can't both keep something in RAM for the majority of cases and still make it robust. The fact that embedding state in the URL is tedious is neither here nor there, but in any case it's a pretty garbage excuse. You know what's more tedious than writing code to pass a few integers around in links? Thousands of…

You seem to not be aware of the architecture of this site, it's all run out of ram, no database; just simple lazy load on demand files on a single server running in a single process. Because of this, memory is tight, that's why those closures are purged. It simply means pg hasn't had the time to convert more of the prototyped code into production stateless code that always works. But that's his prerogative, this site…

There's something on disk isn't there? Or does a power outage mean poof it's all gone?

Anyway, you're totally right that it's his prerogative to build a site however he sees fit, and it's my prerogative to leave, but it's also my prerogative to complain about it and call it half-assed. I do build websites as well, so I'm not just armchair commenting.

Re: "Unknown or expired link." - Why?

#128

Post by odobenus »

Everyone who has literally answered the question "Why?" has completely missed the point. What would PG say about a primary site feature that is so completely broken that it drives users to complain actively, and maybe stop using the site? That it is their problem because they don't understand the technical details? Well, obviously, no one is losing any money here, so maybe that's the answer after all.

Re: "Unknown or expired link." - Why?

#129

Post by colanderman »

apgwoz wrote: post #71
piinbinary wrote: post #16

Earlier quoted context omitted.

I would be interested to know how much state is in those closures. If it is less than 200 or so bytes, it would not be impractical to encode it (b64) in the url for the next page (rather than a reference to the state).

Racket has support for serialization of closures and continuations, which it's web server makes extensive use of. It seems like it'd be possible to expose the relevant functions to make that happen, though I have no idea how large the closures actually are once serialized.

I believe the Racket web server works similarly to the Arc server. At least it did last I checked (back when it was still PLT Scheme).

Re: "Unknown or expired link." - Why?

#130

Post by gnaritas »

wvenable wrote: post #120
gnaritas wrote: post #119

Earlier quoted context omitted.

I think you over-estimate what you can do in three hours and underestimate how much non UI stuff there is in trying to keep out garbage and prevent voter rings and score karma and vary behavior based on that karma and probably a dozen other little small things.

I certainly don't think 3 hours is enough for this site but then pg has put in a lot more time in than just his initial prototype as well. But the functionality of closures and server-side state aren't needed for this kind of site at all. Nothing you mentioned above seems related to that functionality either.

It's not relevant whether they're needed or not if you use closures as your default linking mechanism because it's always the easier route. They're not needed for any site ever, they're just damn convenient. You go back through the app replacing closures with more verbose and direct linking as time permits; clearly pg hasn't found the time yet.
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