Live data from Hacker News

Facebook Down?

facebook.com

171–180 of 208 posts

Re: Facebook Down?

#171

Earlier quoted context omitted.

The global outage drinking game: bad DNS config push - 1 shot routing loop - 2 shots third party advertising your routes - 3 shots power outage at data centre it turns out everything depends on despite decades and millions in engineering to avoid precisely that - 4 shots Wolves ate through fiber - 5 shots And it was a full moon - 6 shots Single service failure, but service has not been restarted in 5 years, and no lo…

5 is often broken down to “rain fade” and “backhoe fade.” My favorite can’t-restart story is “the shared password manager is down, we need a hardware crypto key to restart it, the key is in the safe, and the safe’s combination was in the shared password manager.”

In a similar vein, the alternative option for 7 was a cyclical dependency introduced since last restart

Re: Facebook Down?

#172

Earlier quoted context omitted.

The global outage drinking game: bad DNS config push - 1 shot routing loop - 2 shots third party advertising your routes - 3 shots power outage at data centre it turns out everything depends on despite decades and millions in engineering to avoid precisely that - 4 shots Wolves ate through fiber - 5 shots And it was a full moon - 6 shots Single service failure, but service has not been restarted in 5 years, and no lo…

DST can be such a hassle. It affects our reports and change requests.

An adtech company once freaked out over a sudden 4% revenue drop, until someone pointed out that yesterday was 4% shorter than the day before.

Re: Facebook Down?

#173

Earlier quoted context omitted.

At that size of a company there's usually blast radius restrictions and per-role permissions. I don't expect anyone has enough rights to "delete Facebook" on their own.

I guarantee you that there are 100+ people who could take Facebook down for 24+ hours if they went rogue. For example the people responsible for the bootup scripts of Facebook infra could sneak in a "0 0 1 * * /bin/rm -rf ${TEMPDIR}/*" into crontab... They'd set the commit message as "clear out temp monthly" and it would get deployed across the entire fleet till in the first of next month every disk at Facebook gets…

That’s...now how any of this works. You can’t just change integrity-bearing things without FIM systems kicking in. And you’d need collusion to get something mainlined that would bypass that.

Re: Facebook Down?

#174
post #122

Earlier quoted context omitted.

Every company's actual status page (and news feed) is on Twitter, no matter what else they say. I don't know where Twitter hosts their real status page. Probably Facebook. Notably, Facebook hasn't updated theirs, though.

> every company's actual status page is on Twitter Clearly you have not experienced the absolute joy of a mission-critical locked-in-vendor B2B SaaS with no status page, no active Twitter presence, and the effective status page being a chat widget that routes to a person overseas who says "oh yeah this is a known outage on our main product please stay tuned" but there's no attempt to proactively make it visible to cl…

During the recent Microsoft Azure AD outage, I attempted to use the chat widget. Selecting "Technical support" or "Billing Support" both seemed to return 500 status codes while the "Sales Support" routed somewhere else and connected me to a person, perfectly fine. Presumably the sales team don't use Azure for anything.

Re: Facebook Down?

#175

Earlier quoted context omitted.

I guarantee you that there are 100+ people who could take Facebook down for 24+ hours if they went rogue. For example the people responsible for the bootup scripts of Facebook infra could sneak in a "0 0 1 * * /bin/rm -rf ${TEMPDIR}/*" into crontab... They'd set the commit message as "clear out temp monthly" and it would get deployed across the entire fleet till in the first of next month every disk at Facebook gets…

How though? Every past author of that script would be notified of such a change. It'd be insane if all of them would pretend they didn't see it and accept that change.

It would be hidden amongst a big refactor, and it would have a bunch of unit and integration tests that all work correctly (because they do set the environment variables correctly).

Writing code that appears to do one thing and actually does another is very doable - you only need to hide one malicious line amongst thousands in a code review, while the reviewer needs to inspect every line.

Besides, the vast majority of code reviews are 10 minutes or less.

Re: Facebook Down?

#176

Earlier quoted context omitted.

At that size of a company there's usually blast radius restrictions and per-role permissions. I don't expect anyone has enough rights to "delete Facebook" on their own.

I guarantee you that there are 100+ people who could take Facebook down for 24+ hours if they went rogue. For example the people responsible for the bootup scripts of Facebook infra could sneak in a "0 0 1 * * /bin/rm -rf ${TEMPDIR}/*" into crontab... They'd set the commit message as "clear out temp monthly" and it would get deployed across the entire fleet till in the first of next month every disk at Facebook gets…

Facebook servers do not have cron installed.

Re: Facebook Down?

#177

We're obviously going to take this opportunity to dunk of facebook because it's funny, but let's not forget that there are some valuable cultural assets that facebook hosts, with groups such as "Foods with threatening auras" and "Animals in predicaments." I long ago tamed the facebook engagement algorithm by simply unfollowing everything and everyone except these legitimate, useful types of entertainment venues.

Don't forget "The Same Photo of a Gravel Pile Every Day." Almost makes the decline of Western civilization worth it.

Re: Facebook Down?

#178

Earlier quoted context omitted.

I guarantee you that there are 100+ people who could take Facebook down for 24+ hours if they went rogue. For example the people responsible for the bootup scripts of Facebook infra could sneak in a "0 0 1 * * /bin/rm -rf ${TEMPDIR}/*" into crontab... They'd set the commit message as "clear out temp monthly" and it would get deployed across the entire fleet till in the first of next month every disk at Facebook gets…

That’s...now how any of this works. You can’t just change integrity-bearing things without FIM systems kicking in. And you’d need collusion to get something mainlined that would bypass that.

You don't need collusion - just a code reviewer not paying proper attention.

Re: Facebook Down?

#179

Earlier quoted context omitted.

The global outage drinking game: bad DNS config push - 1 shot routing loop - 2 shots third party advertising your routes - 3 shots power outage at data centre it turns out everything depends on despite decades and millions in engineering to avoid precisely that - 4 shots Wolves ate through fiber - 5 shots And it was a full moon - 6 shots Single service failure, but service has not been restarted in 5 years, and no lo…

5 is often broken down to “rain fade” and “backhoe fade.” My favorite can’t-restart story is “the shared password manager is down, we need a hardware crypto key to restart it, the key is in the safe, and the safe’s combination was in the shared password manager.”

Coincidentally, I'm in the same predicament with Facebook, itself.

I can't log in to Facebook because Facebook wants approval from the Duo Mobile 2FA app. The 2FA app won't approve the login because it wants a code that can only be obtained by logging in to Facebook.

Solution: Deleted both Duo Mobile and Facebook apps. Moved on with my life.

Re: Facebook Down?

#180

Earlier quoted context omitted.

I guarantee you that there are 100+ people who could take Facebook down for 24+ hours if they went rogue. For example the people responsible for the bootup scripts of Facebook infra could sneak in a "0 0 1 * * /bin/rm -rf ${TEMPDIR}/*" into crontab... They'd set the commit message as "clear out temp monthly" and it would get deployed across the entire fleet till in the first of next month every disk at Facebook gets…

Facebook servers do not have cron installed.

Example using widely understood tooling... But there are plenty of other one line changes with similar impact
Post reply on HN