The case of the 500-mile email | Hacker News Reader

The case of the 500-mile email

ibiblio.org

80 pointsmqt28 comments

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And I was fairly certain I hadn't enabled the "FAIL_MAIL_OVER_500_MILES" option.

That would be a great feature to have as part of a "new admin initialization" program or something :D

An old story but one of my favorites =)

The case of the 500-year anecdote.

I thought it was a made up story till i got to the end O.o

"Have you run tcpdump or strace?"

If you're curious about where to start debugging, this blog post gives a good rundown:

http://sysadvent.blogspot.com/2008/12/sysadmin-advent-day-1....

Oldie but a goodie. Highly recommend reading this but if you don't want to..

SPOILER - though you should be reading the article first anyway if you care!

An accidental downgrade of Sendmail made Sendmail have a zero second timeout on sending mail that ultimately worked out at 3 milliseconds, just enough to hit servers within a certain radius..

I bet there are several pieces of software that could have a zero timeout triggered in a similar way. The difficulty of figuring it out? About the same as with this guy ;-)

Yeah it's old but I never did figure out how his geostatisticians knew how to see if the email went further than 500 miles...I mean, that'd mean they know to measure where the mail servers are rather than the actual user, right? oh well.

Back then, most of the users were probably within a local telephone call of their mail server.

back then in the good old days of 2002...

(not sure if i'm joking or serious. depends on one's perception of chance)

Read the first line of his description again:

"The following is the 500-mile email story in the form it originally appeared, in a post to sage-members on Sun, 24 Nov 2002."

The story appeared on the SAGE mailing list in 2002. It actually takes place between 1994 to 1997.

http://www.ibiblio.org/harris/500milemail-faq.html

Exactly. In 1994, I was in the same town as my mail server. Since these were emails from professors, probably to other academic types, many of them probably used their school's servers, which would have been local.

Also, most of the people they were trying to write to were probably at academic institutions, which function as their own ISP.

I'm a little unclear on one point: knowing that 3ms * 186000 miles/sec is roughly 550 miles, wouldn't the radius be ~275 miles? (Round trip travel time before timeout)

That is assuming that packets could actually travel that fast through a wire.

my shell doesn't have "units": http://www.google.com/search?q=.003+lightseconds+in+miles

units isn't a shell function; it's a program that's a standard part of Unix. You can install GNU Units on Linux.

It even lets you define your own units in units.dat. Pretty cool.

http://en.wikipedia.org/wiki/Units_(Unix)

I've really got to learn to stop posting anything to HackerNews that in any way can be construed as an admission of weakness or vulnerability. I sensed that was the case here when I was writing, but didn't think it was necessary to hide it. I will be more careful in future to not reveal more than is absolutely necessary, and so avoid this typical, casually condescending reply. It's annoying because it's the "mistake" that gets seized on, instead of what I'm saying... as if there's more interest in correction than communication.

Maybe I am alone here in disliking unsolicited advice, but ironically, when I ask a question here, I usually don't get any help...

...so perhaps the secret is not to ask, but state something that incidentally reveals the lack of knowledge, so the scent of inexcusable ignorance rouses the instinctive hacker display of superior knowledge. I will try this.

Or maybe, I am just not a hacker. Although I love coding (especially to help other people) and I'm not a corporate type, I am coming to think this more and more; because behaviour like giving unsolicited advice seems to be totally acceptable and approved of on sites like this, but by my values is a form of trolling, and has never sat well with me.

EDIT I just checked the site mqt lists in his profile (http://mark.nirv.net/), and judging by his May 26, 2007 entries, he does troll at times ("What a f______ p___"; "Use a spell checker next time, a______." - to me, that's really abusive). Trolls have sometimes gotten under my radar by combining genuine knowledge and apparent helpfulness with their trolling. Oh well, you live and you learn; without risking mistakes and uncongeniality, one cannot learn.

I didn't think mqt's response was remotely condescending, and I'm the queen of "I'm just trying to help" bitchiness.

I think you need to be aware that not everyone who disagrees with you or fails to kiss your ass is trolling.

Or, in true trolling style: stop whining.

mqt didn't disagree with me, and I didn't say that he did.

Those are your thoughts.

> mqt didn't disagree with me, and I didn't say that he did.

Neither did I.

> I think you need to be aware that not everyone who disagrees with you or fails to kiss your ass is trolling.

EDIT I can't believe I've gotten drawn into this. Your use of loaded terms "bitchiness", "ass", "whining", giving your opinions as if they were truth, issuing commands, all in terms that didn't relate to the comment you were replying to, should have tipped me off. No more responses from me. Bye.

"not everyone" != mqt

I don't know what the rest of these guys are talking about. That guy sure was a jackass for trying to show you how to get the thing you were complaining about not existing.

And those other guys were total jerks for not waiting with baited breath for you to post your questions. And the guy with the blog where he said a dirty word? THE NERVE! I am totally with you, people who state opinions on their personal websites without being asked for them first are total trolls!

The internet SUCKS! Let's go to the real world where everyone is nice!

whoa whoa whoa

You're doing the "text communication has no sense of tone, body language, or other important indirect communication, so I'll just assume you're being a dick" thing.

It's all cool. Try and assume people aren't just being dicks.

Giving you helpful information is not trolling.

You mentioned that "units" wasn't part of your system and he pointed out that it's actually a Unix base program (i.e. part of BSD/Solaris/Darwin) that's installable separately for GNU-based systems.

What's the problem here? Did you really need to comb through his blog and call him out like that?

why did he freakout? surely the idea of distance = ping time and there being some sort of timeout going on is one of the simplest explanations?

You're obviously not a sysadmin, living on the front line between the non-technical, and mountains of computer hardware. I've worked at more than a few places where "I can't send an email more than 500 miles." translates to "One person 500 miles away has had their automatic spam filter nab my message."

I'm much more inclined to believe user error first. That said, the words "consultant" and "upgrade" give me cold chills...

I am not a sysadmin either but I had exact same reaction as nazgulnarsil. I would think a sysadmin's thought process would follow the path of distance->latency->timeout pretty quickly. In other words, I understand what you are saying about sysadmins having to deal with non-technical users, but in this case I actually think the "customer was right". From what I've gathered from this story, the end user was highly analytical in figuring out the exact issue and made an intelligent and acccurate analysis. The sysdamin's emotional filter was the problem, if anything.

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