We deleted the production database by accident

https://keepthescore.co/blog/posts/deleting_the_production_database/

by caspii • 6 years ago

446 423 6 years ago

keepthescore.co

smadge• 6 years ago

SSH tunnel from localhost to prod on database port?

rmrfrmrf2• 6 years ago

vscode remote extension perhaps

sfkdjf9j3j• 6 years ago

That's my guess too. Naughty naughty. That means his production creds are the same as his development creds!

EdwardDiego• 6 years ago

Yeah that's my guess, and likewise biggest concern - if the credentials are the same in dev and prod, it increases risk surface.

macNchz2• 6 years ago

A likely culprit. Having worked on a bunch of early-stage products where best practices are a distant future dream, I’ve developed a few “seatbelt” habits I use to avoid these kinds of things. One of them is to always use a random high-number local port if I’m tunneling to a production service.

Another is to change my terminal theme to a red background before connecting to anything in production...never want to click the ‘psql ...’ tab, run “truncate table app_user cascade” and realize afterwards it was a lingering connection to production...

rmrfrmrf2• 6 years ago

what's a situation where you'd be tunneling to a production service?

sdepablos• 6 years ago

VPN to production and same hostname for dev and prod?

kerng2• 6 years ago

...and same credentials apparently also - there are lots of things that could have prevented something like this.

k__• 6 years ago

Keep going, I'm writing this down!

asddubs3• 6 years ago

could also be that they just have an if staging/else somewhere for the credentials (but of course this isn't a counterpoint to the root of your point - the script wiping the database shouldn't be using anything that does something like this, and you probably shouldn't do it at all)

tedk-422• 6 years ago

Yeah this stuck out to me as well. To be honest if they ARE using the same creds in prod as they are in dev, this is the first thing they should fix because it would have easily prevented the whole mess.

I'll give them the benefit of the doubt and suggest that it wasn't the case and that it's unlikely that a dev or OPs person was tunnelling through a bastion of some kind to run the script.

If they pulled their credentials from a store and populated the config object that way, it's very possible someone actually loaded the production credentials by mistake into the development secrets file. The CI/pipeline system has permissions/network access to deploy to any environment, hence how it ran the script to drop the table.

I'm purely speculating another alternative to the much worse case of the tunnelling scenario outline.

rullelito• 6 years ago

LOL, I forgot how few safety measure startups have in place.

xwdv• 6 years ago

Given the short time frames that startups aim to capture value in its not worth investing time in safety until you have plenty of capacity to spare later.

tluyben2• 6 years ago

Like this never happens in big corps: sure, mostly on departmental level but still enterprises, not startups. They try to escape the annoying and slow as molasses dba’s/devops and install/create/buy/saas systems to avoid the red tape. But then the same things as with startups go wrong. And rather often too; we often had these calls asking if we could restore.

Obviously there are plenty of large enterprise wide data breaches, which, I would say is actually worse than losing a day of data in a lot of cases. So also not so many satefy measures, again, worse than startups; at least they have an excuse of being understaffed and underfunded.

fencepost• 6 years ago

Does the database name value allow specifying a host as part of it?

mijoharas• 6 years ago

This is what I came to say. Postgres usually allows a connection string that contains all the details as the database name postgres://username:password@host:port/dbname and I think it will take priority over separately specified host, depending on the client.

Tough way to learn that lesson though.

muststopmyths• 6 years ago

Note that host is hardcoded to localhost. This means it should never connect to any machine other than the developer machine. We’re too tired to figure it out right now. The gremlins won this time.

Obviously, somehow the script ran on the database host.

some practices I've followed in the past to keep this kind of thing from happening:

* A script that deletes all the data can never be deployed to production.

* scripts that alter the DB rename tables/columns rather than dropping them (you write a matching rollback script ), for at least one schema upgrade cycle. you can always restore from backups, but this can make rollbacks quick when you spot a problem at deployment time.

* the number of people with access to the database in prod is severely restricted. I suppose this is obvious, so I'm curious how the particular chain of events in TFA happened.

amluto2• 6 years ago

I have a little metadata table in production that has a field that says “this is a production database”. The delete-everything script reads that flag via a SQL query that will error out of it’s set in the same transaction as the deletion. To prevent the flag from getting cleared in production, the production software stack will refuse to run if the “production” flag is not set.

at_a_remove• 6 years ago

Nice. Very nice.

jerf• 6 years ago

This is also one place where defense-in-depth is useful. "Has production flag" OR "name contains 'prod'" OR "hostname contains 'prod'" OR "one of my interfaces is in the production IP range" OR etc. etc. You really can't have too many clauses there.

Unfortunately, the "wipe & recreate database" script, while dangerous, is very useful; it's a core part of most of my automated testing because automated testing wipes & recreates a lot.

asimjalis• 6 years ago

I would flip the logic. If database does not have flag that says it is non-production assume it is production.

mcpherrinm• 6 years ago

The blog mentions it's a managed DigitalOcean database, so the script likely wasn't run on the host itself.

More likely, I'd suspect, is something like an SSH tunnel with port forwarding was running, perhaps as part of another script.

jlgaddis3• 6 years ago

the number of people with access to the database in prod is severely restricted

And of those people, there should be an even fewer number with the "drop database" privilege on prod.

Also, from a first glance, it looks like using different database names and (especially!) credentials between the dev and prod environments would be a good idea too.

PeterisP• 6 years ago

One aspect that can help with this is separate roles/accounts for dangerous privileges.

I.e. if Alice is your senior DBA who would have full access to everything including deleting the main production database, then it does not mean that the user 'alice' should have the permission to execute 'drop database production' - if that needs to be done, she can temporarily escalate the permissions to do that (e.g. a separate account, or separate role added to the account and removed afterwards, etc).

Arguably, if your DB structure changes generally are deployed with some automated tools, then the everyday permissions of senior DBA/developer accounts in the production environment(s) should be read-only for diagnostics. If you need a structural change, make a migration and deploy it properly; if you need an urgent ad-hoc fix to data for some reason (which you hopefully shouldn't need to do very often), then do that temporary privilege elevation thing; perhaps it's just "symbolic" but it can't be done accidentally.

StavrosK2• 6 years ago

Someone SSHed to production and forwarded the database port to the local machine to run a report, then forgot about the connection and ran the deletion script locally.

cutemonster5• 6 years ago

That has happened? Or was it a thought about what could have happened elsewhere?

freitasm• 6 years ago

Lost seven hours of data? Daily backup with no transaction log backup?

Whoa.

lisper• 6 years ago

Yeah, this. The problem is not that the production database was deleted by accident. The problem is that it was possible to (unrecoverably) delete the production database by accident.

jrockway• 6 years ago

You'll find that most users of cloud databases are in this boat. For example, on GCP, deleting the database instance deletes the backups! You have to write your own software if you want to survive that button click.

xnyan• 6 years ago

localhost is an abstraction, it's a non-routable-outside-your-machine network...except it's not. It's nothing more than normal TCP traffic except with a message to the OS and other programs that whatever is on that local computer network, you don't want it routed outside the local computer.

There's absolutely nothing stopping anything with access to localhost from routing it anywhere that process wants. Does not even take a malicious actor, all kinds of legit programs expose localhost. It's really not something you should use for anything except as a signal to other well-behaving programs that you are using the network stack as a machine-local IPC bus.

defen2• 6 years ago

The fact that the production db has the same username/password as the development one is perhaps more troubling.

cortesoft• 6 years ago

It likely doesn't... it probably reads it from the environment or a config role, and since it was in production it had the production credentials.

kerng2• 6 years ago

Yes! This is the biggest mistake probably

Biganon• 6 years ago

They say in the article that it's not the case.

webel0• 6 years ago

This is my greatest fear when it comes to terraform:

terraform destroy

(And either a confirmation or a flag) and everything is deleted.

I know you can add some locks but still :/

malwrar• 6 years ago

You can save yourself from scary operations like deleting everything by a.) not rooting your entire infra in the same main.tf and b.) using Terraform's lifecycle meta-argument: https://www.terraform.io/docs/configuration/resources.html#l...

I like to use the lifecycle feature for suuuper core things that will never be deleted (VPC, r53 zone, etc) and eventually when I start targeting multiple DCs w/ lots of infra I'll eventually move to many state roots (or use tools like Terragrunt, which make things mildly scary again).

gkop• 6 years ago

Also a human should review every plan and confirm before applying, right?

a-b• 6 years ago

Recreate and seed test database is totally ok in RoR world.

I think the main reason of this accident is lack of separation between development and operations.

jacquesm• 6 years ago

This happens more often than you might think.

cblconfederate2• 6 years ago

Computers are just too complex and there are days when the complexity gremlins win.

Wow. But then again it's not like programmers handle dangerous infrastructure like trucks, military rockets or nuclear power plants. Those are reserved for adults

yunruse• 6 years ago

I feel that computers make it easier for this danger to be more indirect, however. The examples you give are physical, and even the youngest of child would likely recognise they are not regular items. A production database, meanwhile, is visually identical to a test database, if measures are not made to make it distinct. Adults though we may be, we're human, and humans can make really daft mistakes without the right context to avoid them

Waterluvian• 6 years ago

All of those items have a lot of safety software in them.

PurpleFoxy• 6 years ago

There are also countless safety measures on physical items that have been iterated on over decades to prevent all kinds of accidents. Things like putting physical locks on switches to prevent machinery being turned on while people are working on it.

Can you imagine if instead of a physical lock it just said “are you sure you wish to turn on this machine”. “Of course I want to turn it on, that’s why I pressed the button”

Some software makes it a lot harder for the user to mess up now. When deleting a repo on GitLab you have to type the name of the repo before pressing delete and then it puts it in a pending deletion state for a month before it’s actually deleted. Unfortunately for developers we typically get minimal cli tools which will instantly cause a lot of damage without any way to undo.

im3w1l• 6 years ago

So, silly idea. What if, to work on the production database, you had to go into the special production room, colored in the special production color, scented with the special production perfume, and sit on a just tiny bit uncomfortable production chair.

Basically make it clear even to the caveman brain that things are different.

geofft• 6 years ago

I'm not sure I follow your point - I think you'll find the same attitude towards complexity by operators of military rockets and nuclear power plants. If you look at postmortems/root-cause analyses/accident reports from those fields, you'll generally find that a dozen things are going wrong at any given time, they're just not going wrong enough to cause problems.

codegladiator4• 6 years ago

We already know humans make mistakes. But for this particular scenario lets blame computers.

eezurr• 6 years ago

One explanation for the author feeling that way is that the system is has too much automation. Being in a situation where you take on more responsibilities of the system at a shallower level leads to less industry expertise. This, as it turns out, places the security of the system in a precarious position.

These is pretty common, as devs tool belts have grown longer over time.

I think at some point we will stop automating or reverse some of the automation.

codegladiator4• 6 years ago

too much automation

Literally just the automation of the test suite. That's 1 automation.

These is pretty common

? Waiting for FB to delete their db

ineedasername2• 6 years ago

Yep, I hate when I'm dealing with a system literally comprised of logic and a magic gremlin shows up to ruin my day.

Seems like they though a casual "everyman" type of explanation would suffice, but really who would trust them after this?

cblconfederate2• 6 years ago

I understand that web interfaces are trivial, unimportant work (it s what i do), but how can one sleep with such an unresolved mystery?

jlgaddis3• 6 years ago

The wonderful thing about computers is that they do exactly what they are told to do.

The worst thing about computers? They do exactly what they are told to do.

fma3• 6 years ago

I do a lot of work with middle/high school students. Without fail someone would yell "Why is it doing x!"...to which my standard reply is "Because you told it to".

wruza2• 6 years ago

they do exactly what they are told to do

Well, tell them to UNDROP and see what happens.

junglejoose• 6 years ago

You aren’t a real engineer until you do this. So congrats on the promotion! :)

emerongi• 6 years ago

I wrote a migration that dropped columns for a functionality that was no longer to be used.

Then the client wanted that functionality back. Oops.

Guest42• 6 years ago

Definitely, the likelihood of these things happens goes way up alongside the amount of concurrent tasks, meetings, or other forms of distraction. I’ve seen my fair share of production administration as a side task.

zmmmmm• 6 years ago

Indeed - after incidents like this I usually say, "This is called experience that you can't pay to get for any price. Learn from it well, and value your lesson."

ISL• 6 years ago

I'm a physicist, interested in consulting on both data analysis and precision metrology/hardware projects in general.

That said, I will happily accept consulting fees in return for deleting someone's database in prod, should they so desire.

Edit: Heck, being a white-hat licensed-to-create-mayhem chaos monkey for a few hours a week sounds pretty fun. Email in profile.

li4ick• 6 years ago

Yeah, imagine if a bridge engineer said the same thing: "You aren't an engineer until your bridge collapses. Congrats!" I am starting to hate tech culture. Nobody cares about correctness and discipline. Mention "math" and everybody spreads like cockroaches.

Negitivefrags• 6 years ago

If you are using postgres, configure it to keep the WAL logs for at least 24 hours.

They could have used point-in-time recovery to not lose any data from this at all.

yjftsjthsd-h2• 6 years ago

If you can do this, then yes by all means do it, but that has significant impact on disk usage.

koolba• 6 years ago

It doesn’t have to be local. In fact it shouldn’t be local anyway as backups accessible to be deleted from the source aren’t real backups any way.

You can the restore from a recent base backup and roll forward the WAL to just before the snafu.

xtracto3• 6 years ago

This happened to me (someone in my team) a while ago but with mongo. The production database was ssh-tunneled to the default port of the guys computer and he ran tests that cleaned the database first.

Now... our scenario was such that we could NOT lose those 7 hours because each customer record lost meant $5000 usd penalty.

What saved us is that I knew about the oplog (binlog in mysql) so after restoring the backup i isolated the last N hours lost from the log and replayed it on the database.

Lesson learned and a lucky save.

fma3• 6 years ago

Same happened to me many years ago. QA dropped the prod db. It's been many years but if I recall, I believe in the dropdown menu of the MongoDB browser, exit & drop database were next to each other...Spent a whole night replaying the oplog.

No one owned up to it, but had a pretty good idea who it was.

vanviegen2• 6 years ago

No one owned up to it, but had a pretty good idea who it was.

That sounds like you're putting (some of) the blame on whoever misclicked. As opposed to everyone who has allowed this insanely dangerous situation to exist.

stennie• 6 years ago

Which MongoDB browser or admin tool are you referring to?

I haven't seen this design in practice using MongoDB Atlas or Compass, but would hope for an "Are you really sure?" confirmation in an admin UI.

3np3• 6 years ago

A dangling port-forward was my first thought to how this happened.

hannofcart2• 6 years ago

It takes a great deal of integrity to admit that you deleted a database because you were mucking around in your infra after red wine.

And it bodes well for your firm that that doesn't get you fired either.

These things happen to the best of us but having dealt with it responsibly and honestly as a team is something you can be proud of IMO.

bachmeier• 6 years ago

And it bodes well for your firm that that doesn't get you fired either.

Maybe there's more than one interpretation of "bodes well" but not knowing how to do the one thing customers were paying you to do isn't consistent with my definition.

having dealt with it responsibly and honestly as a team is something you can be proud of IMO.

"We were drinking wine and deleted the database and now your data's gone LOL" is not something that should make you proud.

hannofcart2• 6 years ago

Please re-read what I wrote. I was praising their honesty. Not egging them on to be more sloppy.

amingilani4• 6 years ago

Happens to all of us. Once I required logs from the server. The log file was a few gigs and still in use. so I carefully duplicated it, grepped just the lines I needed into another file and downloaded the smaller file.

During this operation, the server ran out of memory—presumably because of all the files I'd created—and before I know it I'd managed to crash 3 services and corrupted the database—which was also on this host—on my first day. All while everyone else in the company was asleep :)

Over the next few hours, I brought the site back online by piecing commands together from the `.bash_history` file.

tempestn• 6 years ago

Seems unwise to have an employee doing anything with production servers on their first day, let alone while everyone else is asleep.

amingilani4• 6 years ago

It does but that was an exceptional role. The company needed emergency patches to a running product while they hired a whole engineering team. As such, I was the only one around doing things, and there wasn't any documentation for me to work off of.

I actually waited until nightfall just incase I bumped the server offline because we had low traffic during those hours.

netheril96• 6 years ago

Why does the DB get corrupted? Does ACID mean anything these days?

theamk4• 6 years ago

Not original poster, but up to 2010, default MySQL table type was MyISAM, which does not support transactions.

amingilani4• 6 years ago

It was an older MongoDB in my case. :)

codegladiator4• 6 years ago

Computers are just too complex and there are days when the complexity gremlins win.
However, we will figure out what went wrong and ensure that that particular error doesn’t happen again.

How can you say statement 2 just after statement 1 ? Isn't statement 1 just plain acceptance of defeat ?

And looking at all the replies here, is this a feel good thread for the mistakes you made ?

ssalka• 6 years ago

I like to think that, by addressing the known bugs as they pop up, over time you can box the complexity gremlins into tighter and more predictable spaces. Though as long as humans are building these systems, that box will always be there, and the predictability of those gremlins' behavior will only go so far.

codegladiator4• 6 years ago

I am not sure what the bug was here ? Everything worked as intended to be.

caconym_• 6 years ago

In context, statement 1 regards proactively eliminating all bugs and risks. Statement 2 regards understanding the root cause of this particular incident and reactively fixing it so it won’t happen again.

Acknowledging statement 1 doesn’t mean giving up—it simply means being clear and realistic about the nature and scale of the problem we’re facing when we try to build complex software systems. In the face of that we can give up, or we can just do the best we can, and it sounds more like these people are doing the latter.

suzzer99• 6 years ago

We have something similar with AWS Cognito. If a user signs up but doesn't go through with the verification process, there's no setting to say "remove them after X days". So we have to run a batch job.

If I screw up one parameter, instead of deleting only unconfirmed users, I could delete all users. I have two redundant checks, first when the query is run to get the unconfirmed users, and then again checking the user's confirmed status before deleting them. And then I check one more time further down in the code for good measure. Not because I think the result will be different, but just in case one of the lines of code is altered somehow.

I put BIG LOUD comments everywhere of course. But it still terrifies me.

6nf• 6 years ago

Soft deletes reduces the scariness

fideloper• 6 years ago

RDS is so very worth paying for this type of issue (in many cases, obviously $60 to multiple thousands a month isn’t great for everything).

Otherwise having a binlog based backup (or WAL, I guess, but i don’t know PG that well) is critical.

The key point there is they provide point in time recovery possibilities (and even the ability to rewrite history).

latch• 6 years ago

Barman (1) is really easy to setup and lets you avoid the many pitfalls of RDS (lower performance, high cost, no superadmin, no arbitrary extensions, waiting for releases, bad log interface).

(1) https://www.pgbarman.org/

exabrial• 6 years ago

If you keep configuration in the environment (/etc/default/app-name) rather than in the application package, it's nearly impossible to make this mistake (especially with proper firewall rules). You can even package your config as a deb and keep it encrypted version control.

danellis• 6 years ago

after a couple of glasses of red wine, we deleted the production database by accident
It’s tempting to blame the disaster on the couple of glasses of red wine. However, the function that wiped the database was written whilst sober.

It was _written_ then, but you're still admitting to the world that your employees do work on production systems after they've been drinking. Since they were working so late, one might think this was emergency work, but it says "doing some late evening coding". I think this really highlights the need to separate work time from leisure time.

beervirus• 6 years ago

Sounds like they weren't trying to do work on production.

cle2• 6 years ago

No. Your systems and processes should protect you from doing something stupid, because we’ve all done stupid things. Most stupid things are done whilst sober.

In this case there were like 10 relatively easy things that could have prevented this. Your ability to mentally compile and evaluate your code before you hit enter is not a reliable way to protect your production systems.

Coding after drinking is probably not a good idea of course, but “think better” is not the right takeaway from this.

TedDoesntTalk• 6 years ago

Coding after drinking is probably not a good idea

I’ve done some of my most productive work this way. Not on production systems fortunately, and not in a long time.

bigbubba2• 6 years ago

You know it's totally feasible to make a car that won't turn on for drunk people. Should those systems be installed on all cars, in pursuit of creating systems that don't permit stupid actions?

Maybe such a breathalyzer interlock could be installed on your workstation too. After all, your systems and processes should prevent you from stupid things.

watwut3• 6 years ago

Most stupid things are done whilst sober.

That is because most companies these days have processes around drinking in workplace, coming in drunk and working drunk.

Most mistakes are done sober only in environments where drinking couple of vine cups and then doing production change is considered unacceptable. In environment where drunk people work, mistakes are made when drunk.

bstar772• 6 years ago

I am not a drinker myself (drink 1-3 times a year), but in the past I have coded while slightly buzzed on a few occasions. I could not believe the level of focus I had. I never investigated it further, but I'm pretty sure the effects of alcohol on our coding abilities is not nearly as bad as it affects our motor skills. Imo, fatigue is far worse.

emodendroket6• 6 years ago

I've found just the opposite. Any booze at all and I basically can't work for hours.

henearkr• 6 years ago

When I was not yet a teetotaler, each time I was hitting my maths textbooks after a few drinks, I could not believe my level of focus, and everything was clear and obvious. Textbook pages were flying at a speed never seen.

Of course the next day, when re-reading the same pages, I was always discovering that the previous day I had everything wrong, nothing was obvious, and all my reasoning when with alcohol was false because simplistic and oblivious of any mathematical rigor.

3np3• 6 years ago

For me it's really hit and miss - it can either increase focus and motivation, invigorate the mind, while reducing distractions. Other times it has the opposite effect. Same with cannabis. The cannabis absolutely took a decade or so of recreational use until I discovered/developed coding well under the influence.

Though I'm talking one or two drinks here, not firing up vscode after a night out or going through a bottle of rum.

jnsaff22• 6 years ago

https://xkcd.com/323/

cranekam• 6 years ago

The whole piece has a slightly annoying flippant tone to it. We were drunk! Computers just.. do this stuff sometimes! Better to sound contrite and boring in such a situation IMO.

Also I agree with other comments: doing some work after a glass or two should be fine because you should have other defences in place. “Not being drunk” shouldn’t be the only protection you have against disaster.

danjac• 6 years ago

The Exxon Valdez comes to mind - the company blamed the drunk captain, but this was just part of huge systemic failures and negligence.

caspii3• 6 years ago

Yeah, I agree I'm being slightly flippant.

But it's just a side-project and I will continue late night coding with a glass of wine. I find it hugely enjoyable.

I would have a different mind-set if I was writing software for power stations as a professional.

murillians• 6 years ago

I think it's just a joke

danielh• 6 years ago

According to the about page, "the employees" consist of one guy working on it in his spare time.

caspii3• 6 years ago

I have no employees. I only have myself to blame

mbroshi• 6 years ago

I love this post. This sort of thing happens to everyone, most people just are not willing to be so open about it.

I was once sshed to the production server, and was cleaning up some old files that got created by an errant script, one which file was '~'. So, to clean it up, I type `rm -rf ~`.

meowface• 6 years ago

Somewhat similar story from many years ago. Was in ~/somedirectory, wanted to clear the contents, ran `rm -rf *`. Turns out somewhere in between I had done a `cd ..`, but I thought I was still in the child directory. Fastest Ctrl+C ever once I saw some permission errors, but most of the home directory was wiped in that second or two.

Didn't have a backup of it unfortunately, though thankfully there wasn't anything too critical in there. Mostly just lost a bunch of utility scripts and dotfiles. I feel like it's beneficial in the long run for everyone to make a mistake like this once early on in their career.

wruza2• 6 years ago

It would be beneficial for `rm` to have a way for making `trash` mode the default mode of operation. Unix shell is prone to errors like this beyond all reason. And nobody would die typing:

  fs.delete(shell.expand('*'), recursive:yes)
  fs.undo()

or something like that with completion helpers. Our instruments usually lack any safety in general, and making them safe is hard, especially when you're just a worker and not a safety expert. All the world today benefits from mistake-friendly software, except for developers who constantly walk on ui minefields.

anonunivgrad• 6 years ago

I wouldn’t want to be on the wrong side of a lawsuit, defending drunk employees working on production data. What outrageous recklessness. And how imprudent to admit this to the public. Some things are best kept to yourself. No one needs to know that.

tedk-422• 6 years ago

If you built good systems that have reliable backups or rollback mechanisms, dev should be able to have a beer on a friday and do a deployment without worrying about the fire they just caused.

I'd rather a culture where people admit to their mistakes than one where they try hide or get whipped for owning up to them.

We're people after all and some of us like a glass of wine and unwind while still performing our duties as engineers. After all, it's not like we're in charge of life support or critical systems which absolutely cannot fail.

robjan2• 6 years ago

This is someone's side project. I'm doubtful there will be any lawsuits involved

john_moscow4• 6 years ago

Just my 2 cents. I run a small software business that involves a few moderately-sized databases. The day I moved from a fully managed hosting to a Linux VPS, I have crontabbed a script like this to run several times a day:

    for db in `mysql [...] | grep [...]`
    do
        mysqldump [...] > $db.sql
    done
    
    git commit -a -m "Automatic backup"
    git push [backup server #1]
    git push [backup server #2]
    git push [backup server #3]
    git gc

The remote git repos are configured with denyNonFastForwards and denyDeletes, so regardless of what happens to the server, I have a full history of what happened to the databases, and can reliably go back in time.

I also have a single-entry-point script that turns a blank Linux VM into a production/staging server. If your business is more than a hobby project and you're not doing something similar, you are sitting on a ticking time bomb.

Ayesh• 6 years ago

This is what I do too.

The mysqldump command is tweaked to use individual INSERT clauses as opposed to one bulk one, so the diff hunks are smaller.

You can also sed and remove the mysqldump timestamp, so there will be no commits if there are no database changes, saving the git repo space.

mgkimsal• 6 years ago

Any issues with the privacy aspect of that data that's stored in multiple git repos? PII and such?

john_moscow4• 6 years ago

These are private repos on private machines communicating over SSL on non-standard ports with properly configured firewall. The risk is always there, but it's low.

bufferoverflow• 6 years ago

You should really compress them instead of dumping them raw into Git. LZ4 or ZStandard are good.

adzm• 6 years ago

But then you don't have good diffs.

hinkley• 6 years ago

Git repositories are compressed.

candiddevmike2• 6 years ago

Anyone reading the above: please don't do this. Git is not made for database backups, use a real backup solution like WAL archiving or dump it into restic/borg. Your git repo will balloon at an astronomical rate, and I can't imagine why anyone would diff database backups like this.

john_moscow4• 6 years ago

It really depends on your database size. This works just fine for ~300MB databases. Git gc takes pretty good care of the fluff and once every couple of years I reset the repository to prune the old snapshots. The big plus is that you can reuse your existing git infrastructure, so the marginal setup costs are minimal.

You can always switch to a more specialized solution if the repository size starts bugging you, but don't fall into the trap of premature optimization.

jugg1es2• 6 years ago

Not every database is huge. It could be a good solution in certain circumstances.

wolfgang000• 6 years ago

I don't believe having a massive repo with backups would be the ideal solution. Couldn't you just upload the backup to an s3 bucket instead?

michelpp• 6 years ago

Computers are just too complex and there are days when the complexity gremlins win.

I'm sorry for your data loss, but this is a false and dangerous conclusion to make. You can avoid this problem. There are good suggestions in this thread, but I suggest you use Postgres's permission system to REVOKE DROP action on production except for a very special user that can only be logged in by a human, never a script.

And NEVER run your scripts or application servers as a superuser. This is a dangerous antipattern embraced by many and ORM and library. Grant CREATE and DROP to non-super users.

sushshshsh4• 6 years ago

As a mid level developer contributing to various large corporate stacks, I would say the systems are too complex and it's too easy to break things in non obvious ways.

Gone are the days of me just being able to run a simple script that accesses data read only an exports the result elsewhere as an output.

Nextgrid3• 6 years ago

This is why I am against the current trend of over-complicating stacks for political or marketing reasons. Every startup nowadays wants microservices and/or serverless and a mashup of dozens of different SaaS (some that can't easily be simulated locally) from day 1 while a "boring" monolithic app will get them running just fine.

theamk4• 6 years ago

Why are these days gone?

Just a few weeks ago, I set up a read-only user for myself, and moved all modify permission to role one must explicitly assume. Really helped me with peace of mind while developing the simple scripts that access data read only. This was on our managed AWS RDS database,

akerro• 6 years ago

I'm on similar position as you, but I say systems are as complex as their designed made them and it's on you to change it.

moksly• 6 years ago

Why are those days gone? I do it all the time in an organisation with 10,000 employees. I obviously agree with the parent poster in that you should only do such things with users that have only the right amount of access, but that’s what having many users and schemas are for. I don’t, however, see why you’d ever need to complicate your stack beyond a simple python/powershell script, a correct SQL setup, an official sql driver and maybe a few stores procedures.

I build and maintain our entire employee database with a python script, from a weird non-standard XML”like” daily dump from our payment system, and a few web-services that hold employee data in other requires systems. Our IT then builds/maintains our AD from a few powershell scripts, and finally we have a range of “micro services” that are really just independent scripts that send user data changes to the 500 systems that depend on our central record.

Sure, sure, we’re moving it to azure services for better monitoring, but basically it’s a few hundred lines of scripting that, combined with AD and ADDS, does more than a 1 million USD a year license IDM.

bsder• 6 years ago

You can avoid this problem.

No, you can't. No matter how good you are, you can always "rm -rf" your world.

Yes, we can make it harder, but, at the end of the day, some human, somewhere, has to pull the switch on the stuff that pushes to prod.

You can clobber prod manually, or you accidentally write an erroneous script that clobbers prod. Either way--prod is toast.

The word of the day is "backups".

ikiris2• 6 years ago

excuse me, but no. this is harmful bullshit.

Yes, backups are vitally important, but no it is not possible to accidentally rm -rf with proper design.

It's possible to have the most dangerous credentials possible and still make it difficult to do catastrophic global changes. Hell it's my job to make sure this is the case.

centimeter2• 6 years ago

but this is a false and dangerous conclusion to make

Until we get our shit together and start formally verifying the semantics of everything, their conclusion is 100% correct, both literally and practically.

thih9• 6 years ago

You can avoid this problem.

The article isn’t claiming that the problem is impossible to solve.

On the contrary: “However, we will figure out what went wrong and ensure that this particular error doesn’t happen again.”.

auroranil• 6 years ago

Tom Scott made a mistake with a similar outcome as this article, but with an SQL query that is much more subtle than DROP.

https://www.youtube.com/watch?v=X6NJkWbM1xk

By all means, find ways to fool-proof the architecture. But be prepared for scenarios where some destructive action happens to a production database.

heavenlyblue4• 6 years ago

He would not have done that if he were simply using a database transaction for this operation.

DelightOne• 6 years ago

If you use terraform to deploy the managed production database, do you use the postgresql terraform provider to create roles or are you creating them manually?

dvdbloc• 6 years ago

At my job, the company computers are configured to send “localhost” to the local company DNS servers, of which they happily reply with the IP address of the last machine that’s gotten a DHCP lease with the hostname “localhost”. Which happens often. Needless to say, our IT dept isn’t the best.

jzer0cool2• 6 years ago

Could someone explain more what caused the prod wipe? The snip here indicates it is using a 'dev' credential (it is a different pass than prod right?) - how does a db connection occur at all?

fma3• 6 years ago

Good catch. Wouldn't surprise me if there's 1 username/password for all their DB environments.

jzer0cool2• 6 years ago

When looking at the snip again, there is a note that says it uses different a username / password for prod & dev.

I can't see how the OP indicates making a connection to db without the correct credentials to begin with.

heelix• 6 years ago

Ah man, these things happen. One of our developers - very new to elastic - was asked to modify some indexes. Folks were a bit too busy to help or heading out on holiday. One stack overflow answer later... delete and recreate it... and she was off to the races. When the test was tried, it looked like things still worked. A quick script did the same to stage and prod, in both data centers. Turns out that is not a great way to go about it. It deleted the documents. We got lucky, as we still had not killed off the system we were migrating off of and it only took three days of turn and burn to get the data back on the system.

So many lessons learned that day. I trust her with the master keys at this point, as nobody is more careful with production than her now. :)

yla92• 6 years ago

I am sorry this happens.

local_db = PostgresqlDatabase(database=database, user=user, password=password, host='localhost', port=port)

I am guessing this part. Even though the host is hardcoded as "localhost" , when you do a ssh port-forwarding, the localhost might actually be the real production. e.g sudo ssh user@myserverip -L 3333:localhost:3306

sergiotapia• 6 years ago

I did the same thing once by accident and thankfully only lost 1 hour of data. The single lowest point of my career and thinking about the details of that day makes my stomach sink even now as I type this.

I ran a rake db schema dump command of some kind and instead of it returning the schema of the database, it decided to just completely nuke my entire database. Instantly. It's very easy to fuck up so cover your ass gents, and backup often and run your restores periodically to make you can actually do them in case of an emergency.

colechristensen• 6 years ago

This is bad operations.

That it happened meant that there were many things wrong with the architecture, and summing up the problem to “these things happen” is irresponsible, most importantly your response to a critical failure needs to be in the mindset of figuring out how you would have prevented the error without knowing it was going to happen and doing so in several redundant ways.

Fixing the specific bug does almost nothing for your future reliability.

bArray• 6 years ago

Hmm, there seems to be some holes in their system. A database might go down for any reason.

I also have daily backups, but I write logs (locally and regularly copy from the production server) for all database actions to disk for the purpose of checking through them if something goes wrong, or having the option to replay them encase something like this happens. SO you have your database backups as "save points" and the logs to replay all the "actions" for that day.

emodendroket6• 6 years ago

This post is embarrassing. "yeah we were drinking and accidentally nuked the prod DB. Not sure why. Shit happens!" Who would read this and think they should trust this company? Any number of protections could have been taken to prevent this and production access in any state other than fully alert and attentive shouldn't happen unless it is absolutely necessary for emergency reasons

bstar772• 6 years ago

I think it's kind of funny they chose to post this story rather than do a typical post mortem.

tcbasche2• 6 years ago

Yeah why should I treat anything this company does with any level of seriousness? Why should anyone?

It's lucky it's just some online scoreboard because I'm sure as shit this stuff has happened before with more critical systems and it scares the hell out of me that engineers are fine blaming "gremlins" instead of taking responsibility for their own incompetence.

Aeolun6• 6 years ago

taking responsibility for their own incompetence.

I think they’re doing that with this post? At least I find it hard to imagine myself writing down that I’d drunk a few glasses of wine and dropped the production database.

You cannot expect all engineers to be fully versed in the vagarities of database administration. Especially if they’re the only ones working on something.

corobo3• 6 years ago

This reply is embarrassing. It's a person working on their side project. Have a glass of wine mate.

emodendroket6• 6 years ago

A previous post said it was "almost free" and I feel like a less cavalier attitude is called for if people are paying for the service. Otherwise sure it doesn't matter

prh8• 6 years ago

Very unsettled by the flippancy of the entire article

3np3• 6 years ago

And all the emojis on top of that

jugg1es2• 6 years ago

I totally sympathize with you and yours, I've made sphincter-clenching mistakes a handful of times during my 20 years of experience.

This is an abject lesson that understanding human psychology is actually a huge part of good architecture. Automating everything you do in production with a script that is QA tested prior to use is the best way to avoid catastrophic production outages.

It does take a bit longer to get from start to finish, and younger devs often try to ignore it, but it is worth putting a layer of oversight between your employees and your source of revenue.

lysp• 6 years ago

I had a client who had prod database access due to it being hosted internally. They called up saying "their system is no longer working".

After about an hour of investigation, I find one of the primary database tables is empty - completely blank.

I then spend the next hour looking through code to see if there's any chance of a bug that would wipe their data and couldn't find anything that would do that.

I then had to make "the phone call" to the client saying that their primary data table had been wiped and I didn't know what we did wrong.

Their response: "Oh I wrote a query and accidentally did that, but thought I stopped it".

luord• 6 years ago

This is what nightmares are made of.

We’ve learned that having a function that deletes your database is too dangerous to have lying around.

Indeed, anything that might compromise the data, anything that might involve deletion anyway, should require manual confirmation whether you manage the database or it's a service provided.

Sadly, I learned this the hard way too, but at least it was a single column with a non-critical date and not the entire database.

ummonk• 6 years ago

What a frustrating post :( Provides just enough technical detail to pique our curiosity then leaves us hanging.

oppositelock• 6 years ago

You have to put a lot of thought into protecting and backing up production databases, and backups are not good enough without regular testing of recovery.

I have been running Postgres in production supporting $millions in business for years. Here's how it's set up. These days I use RDS in AWS, but the same is doable anywhere.

First, the primary server is configured to send write ahead logs (WAL) to a secondary server. What this means is that before a transaction completes on the master, she slave has written it too. This is a hot spare in case something happens to the master.

Secondly, WAL logs will happily contain a DROP DATABASE in them, they're just the transaction log, and don't prevent bad mistakes, so I also send the WAL logs to backup storage via WAL-E. In the tale of horror in the linked article, I'd be able to recover the DB by restoring from the last backup, and applying the WAL delta. If the WAL contains a "drop database", then some manual intervention is required to only play them back up to the statement before that drop.

Third is a question of access control for developers. Absolutely nobody should have write credentials for a prod DB except for the prod services. If a developer needs to work with data to develop something, I have all these wonderful DB backups lying around, so I bring up a new DB from the backups, giving the developer a sandbox to play in, and also testing my recovery procedure, double-win. Now, there are emergencies where this rule is broken, but it's an anomalous situation handled on a case by case basis, and I only let people who know what they're doing touch that live prod DB.

azeirah2• 6 years ago

Quick tip for anyone learning from this thread.

If you're using MySQL, it's called a binary log and not a Write Ahead Log, it was very difficult to find meaningful Google results for "MySQL WAL"

x87678r• 6 years ago

Interesting, I immediately thought they would have a transaction log, I didn't think it would have the delete as well.

Its a real problem that we used to have trained DBAs to own the data where now devs and automatic tools are relied upon, there isn't a culture or toolset built up yet to handle it.

mr_toad3• 6 years ago

I have all these wonderful DB backups lying around, so I bring up a new DB from the backups

It’s nice to have that capability, but some databases are just too big to have multiple copies lying around, or to able to create a sandbox for everyone.

tzs• 6 years ago

Here is how we had our database deletion error, about 15 years ago. Our DBs had been on leased servers at a hosting company in New York City. They were getting out of the datacenter business so we had to move. We were moving to colocated servers at a Seattle datacenter.

This was the procedure:

1. Restore DB backups in Seattle.

2. Set up replication from NYC to Seattle.

3. Start changing things to read from Seattle, with writes still going to NYC.

4. After everything is reading from Seattle and has been doing so with no problems for a while, change the replication to be two-way between NYC and Seattle.

5. Start switching writes to Seattle.

6. After both reads and writes are all going to Seattle and it has been that way for a while with no problems, turn off replication.

7. Notify me that I can wipe the NYC servers, for which we had root access but not console access. I wasn't in the IT department and wasn't involved in the first 6 steps, but had the most Unix experience and was thought to be the best at doing a thorough server wipe.

My server wipe procedure was something like this.

8. "DELETE FROM table_name" for each DB table.

9. "DROP TABLE table_name" for each DB table.

10. Stop the DB server.

11. Overwrite all the DB data files with random data.

12. Delete all the DB data files.

13. Delete everything else of ours.

14. Uninstall all packages we installed after the base system install.

15. Delete every data file I could find that #14 left behind.

16. Write files of random data to fill up all the free space.

The problem was with step #6. They declared it done and turned it over to me for step #7 without actually having done the "turn off replication" part of step #6. Step #8 was replicated to Seattle.

It took them a while to figure out that data was being deleted and why that was happened.

We were split across three office buildings, and the one I was in had not yet had phones installed in all the offices, and mine was one of the ones with a phone. None of the people whose offices did have phones were in, so they lost a few more minutes before realizing that someone would have to run a couple blocks to my office to tell me to stop the wipe.

It took about 12 hours or so afterwards for them to restore Seattle from the latest backup, and then replay the logs from between the backup time and the start of the deletes.

After that they were overly cautious, taking a long time to let me resume the NYC wipe. They went right up to the point where I told them if we didn't start now we might not finish, and reminded them that those machines had sensitive customer personal information on them and were probably going to end up being auctioned off on eBay by the hosting company. They came to their senses and told me to go ahead.

jw360• 6 years ago

If your script connects to a production database by accident, you have a whole different issue.

boltefnovor• 6 years ago

Companies tend to get really good at backups after events like this.

ineedasername2• 6 years ago

Related: Little Bobby Tables (https://xkcd.com/327/)

rawgabbit2• 6 years ago

The article should be renamed to “We coded a function that drops database tables and were surprised when it broke production.”

aszen3• 6 years ago

I had a narrow escape once doing something fancy with migrations.

We had several MySQL string columns as long text type in our database but they should have been varchar(255) or so. So I was assigned to convert these columns to their appropriate size.

Being the good developer I was, I decided to download a snapshot of the prod database locally and checked the maximum string length we had for each column via a script. Using this script it made a migration query that would alter column types to match their maximum used length keeping the minimum length as varchar (255).

I tested that migration and everything looked good, it passed code review and was run on prod. Soon after we start getting complaints from users that their old email texts have been truncated. I then realize the stupidity of the whole thing, the local dump of production database always wiped out many columns clean for privacy like the email body column. So the script thought it had max length of 0 and decided to convert the column to varchar(255).

I realize the whole thing may look incredibly stupid, that's only because the naming for db columns was in a foreign european language so I didn't know even know the semantics of each column.

Thankfully my seniors managed to restore that column and took the responsibility themselves since they had passed the review.

We still did fix those unusually large columns but this time by simple duplicate alter queries for each of those columns instead of using fancy scripts.

I think a valuable lesson was learned that day to not rely on hacky scripts just to reduce some duplicate code.

I now prefer clarity and explicitness when writing such scripts instead of trying to be too clever and automating everything.

heavenlyblue4• 6 years ago

And you didn’t even bother to do a query of the actual maximum length value of the columns you were mutating? Or at least query and see the text in there?

Basically you just blindly ran the migration on the data and checked if it didn’t fail?

The lesson here is not about cleverness unfortunately.

detaro• 6 years ago

The comment clearly states that they did.

aszen3• 6 years ago

I did see some values and found them reasonable, problem of the whole thing was there were atleast 200 or so tables with dozens of columns each and only two or so tables were excluded from being dumped locally.

So yes I could have noticed their length 0 if I had looked carefully amidst hundreds of rows but since my faulty logic of prod db = local db didn't even consider this possible I didn't bother.

If it had been just 10 to 20 migrations queries that would have been a lot easier to validate but then I wouldn't even have attempted to write a script

EugeneOZ• 6 years ago

I love the honesty, self-irony and transparency of the article. It's sad and annoying to see so many young naive devs writing ”oh they are so bad, it will never happen to me”.

Yes, people are not perfect and computer systems are complex. Admit it and don't be so overconfident.

”Errare humanum est”, prepare your backups.

beefbroccoli• 6 years ago

Anyone else think this is just a clever ad for DigitalOcean?

info7812• 6 years ago

Not really they lost a day of data, toy database.

tijuco2• 6 years ago

That's the reason I never authorize dev machines connect to production. And that's the reason developers hate my security team.

unnouinceput• 6 years ago

Quote: "Note that host is hardcoded to localhost. This means it should never connect to any machine other than the developer machine. Also: of course we use different passwords and users for development and production. We’re too tired to figure it out right now.

The gremlins won this time."

No they didn't. Instead one of your gremlins ran this function directly on the production machine. This isn't rocket science, just the common sense conclusion. Now it would be a good time to check those auditing logs / access logs you're suppose to have them enabled on said production machine.

toredash• 6 years ago

2 cents his hosts file points localhost to the prod db IP

pvorb2• 6 years ago

Yep. Nowadays a kubectl port-forward makes something like this all too easy. They accidentally had the kubecontext point at the production cluster instead of dev, set up the port-forward to the database, and whoops! At least that's how this could happen to me, even with my years of experience in doing unexpected things to production databases.

kjaftaedi• 6 years ago

I think so as well.

It doesn't even make sense to connect to a managed database using 'localhost'.

Managed databases are never localhost. They are hosted outside your VPS and you use a DNS name to connect to them.

dingdingdang• 6 years ago

Yeah, my guess would be that the script got executed on prod server by, ups was I in that terminal window, accident! Localhost is after all the-local-host, no matter what server it's on. Better to also have clear convention regarding name of prod db name versus test db (i.e. "test_mysaas" versus "mysaas").

Plus of course using git with a hook specifically for preview versus production (i.e. "git push production") that way local specific scripts can be stripped even if in same repo.

radu_floricica• 6 years ago

I'm betting on a tunnel, myself. And grandparent is probably wrong, they most likely have dedicated mysql machines so "localhost" will never be the db.

robryan2• 6 years ago

One solution to this is to make sure only the production servers can connect to the production database.

buzer• 6 years ago

My guess would be something like PgBouncer. Someone may have installed it to the production server at some point in the past.

ir123• 6 years ago

If managed DBs on DigitalOcean are anything like those on AWS, you can not run commands directly on them since SSH is prohibited. EDIT: there's also the deal with different credentials for dev and prod envs.

skytreader• 6 years ago

Instead one of your gremlins ran this function directly on the production machine.

Exactly my first hypothesis too. But then keepthescore claims,

of course we use different passwords and users for development and production.

How would this hypothesis explain that?

---

Metadialogue:

John Watson: "I deduce that someone changed the dev config source so that it uses the production config values."

Sherlock Holmes: "My dear Watson, while that is sensible, it seems to me that the balance of probability leans towards their production instance also having the development access credentials."

---

Just my way of saying, I think this case isn't as shut and closed as most comments (including parent) imply. I personally find the /etc/host mapping a likelier hypothesis but even that can't explain how different credentials failed to prevent this. Without more details coming from a proper investigation, we are just piling assumptions on top of assumptions. We are making bricks, without enough clay, as Holmes would say.

thamer• 6 years ago

Agreed, it seems like most people making suggestions above are missing the point about credentials. The code they present explicitly references `config.DevelopmentConfig`:

    database = config.DevelopmentConfig.DB_DATABASE
    user = config.DevelopmentConfig.DB_USERNAME
    password = config.DevelopmentConfig.DB_PASSWORD

One way this could happen is if the objects under `config` were loaded from separate files, and the dev file was changed to a symlink to the prod file. So `config.DevelopmentConfig` always loads /opt/myapp/config/dev.cfg but a developer had dev.cfg -> prod.cfg and the prod credentials and connection details were loaded into `config.DevelopmentConfig`.

Just an idea.

dschuetz2• 6 years ago

As someone else said it below: "hardcoded to localhost" doesn't mean it's hardcoded. It means it goes to whatever localhost resolves to. Really hardcoded should ALWAYS mean: 127.0.0.1

tus88• 6 years ago

Well u have backups right...or did the gremlins eat them?

axegon_• 6 years ago

I did something similar once - I had fiddled with my /etc/hosts and subsequently connected to the production database without realizing. I dropped a table but thankfully it wasn't much of a deal - the monitoring rang the bell and I recreated it a few seconds later. All that happened was that I had logged out several hundred users.

skrebbel• 6 years ago

I'm appalled at the way some people here receive an honest postmortem of a human fuck-up. The top 3 comments, as I write this, can be summarized as "no, it's your fault and you're stupid for making the fault".

This is not good! We don't want to scare people into writing less of these. We want to encourage people to write more of them. An MBA style "due to a human error, we lost a day of your data, we're tremendously sorry, we're doing everything in our power yadayada" isn't going to help anybody.

Yes, there's all kinds of things they could have done to prevent this from happening. Yes, some of the things they did (not) do were clearly mistakes that a seasoned DBA or sysadmin would not make. Possibly they aren't seasoned DBAs or sysadmins. Or they are but they still made a mistake.

This stuff happens. It sucks, but it still does. Get over yourselves and wish these people some luck.

t0mas885• 6 years ago

The software sector needs a bit of aviation safety culture: 50 years ago the conclusion "pilot error" as the main cause was virtually banned from accident investigation. The new mindset is that any system or procedure where a single human error can cause an incident is a broken system. So the blame isn't on the human pressing the button, the problem is the button or procedure design being unsuitable. The result was a huge improvement in safety across the whole industry.

In software there is still a certain arrogance of quickly calling the user (or other software professional) stupid, thinking it can't happen to you. But in reality given enough time, everyone makes at least one stupid mistake, it's how humans work.

suzakus2• 6 years ago

It's a piece of software for scoreboards. Not the Therac-25, nor an airplane.

watwut3• 6 years ago

Yeah, but "pilot was drinking alcohol" would be considerate issue, would lead to fired pilot and would lead to more alcohol testing.

I understand what you are taking about, but aviation has also strong expectations on pilots.

neillyons2• 6 years ago

This sounds quite interesting. Any books you could recommend on the "pilot error" topic.

janoc7• 6 years ago

It is not only that but also realizing that there is never a single cause to an accident or incident.

Even when it was a suicidal pilot flying the plane into a mountain on purpose. Someone had to supervise him (there are two crew members in the cockpit for a reason), someone gave him a medical, there is automation in the cockpit that could have at least caused an alarm, etc.

So even when the accident is ultimately caused by a pilot's actions, there is always a chain of events where if any of the segments were broken the accident wouldn't have happened.

While we can't prevent a bonkers pilot from crashing a plane, we could perhaps prevent a bonkers crew member from flying the plane in the first place.

Aka the Swiss cheese model. You don't want to let the holes to align.

This approach is widely used in accident investigations and not only in aviation. Most industrial accidents are investigated like this, trying to understand the entire chain of events in order that processes could be improved and the problem prevented in the future.

Oh and there is one more key part in aviation that isn't elsewhere. The goal of an accident or incident investigation IS NOT TO APPORTION BLAME. It is to learn from it. That's why pilots in airlines with a healthy safety culture are encouraged to report problems, unsafe practices, etc. and this is used to fix the process instead of firing people. Once you start to play the blame game, people won't report problems - and you are flying blind into a disaster sooner or later.

oblio2• 6 years ago

The user? Start a discussion about using better programming language and you'll see people, even here, blaming the developer.

The common example is C: "C is a sharp tool, but with a sufficiently smart, careful and experienced developer it does what you want (you're holding it wrong").

Developers still do this to each other.

m463• 6 years ago

That reminds me of the time during the rise of the PC when windows would do something wrong, from a confusing interface all the way up to a blue screen of death.

What happened is that users started blaming themselves for what was going wrong, or start thinking they needed a new PC because problems would become more frequent.

From the perspective of a software guy, it was obvious that windows was the culprit but people would assign blame elsewhere and frequently point the finger at themselves.

so yes - an FAA investigation would end up unraveling the nonsense and point to windows.

That said, aviation level of safety is reliable and dependable and few single points of failure and... there are no private kit jets darnit!

There is a continuum from nothing changes & everything works to everything changes & nothing works. You have to choose the appropriate place on the dial for the task. Sounds like this is a one-man band.

ENOTTY• 6 years ago

The idea that multiple failures must occur for catastrophic failure is found in certain parts of the computing community. https://en.wikipedia.org/wiki/Defense_in_depth_(computing)

qz210• 6 years ago

I disagree.

Culturally speaking we like to pat people on their back when they do something stupid and comfort them. But most of the time this isn’t productive because it doesn’t instil the requisite fear required when working out what decision to make.

What happens is we have growing complacency and disassociation from consequences.

Do you press the button on something potentially destructive because your are confident it is ok through analysis, good design and testing or confidence it is ok through trite complacency?

The industry is mostly the latter and it has to stop. And the first thing is calling bad processes, bad software and stupidity out for what it is.

Honestly these guys did good but most will try and hide this sort of fuck up or explain it away with weasel words.

jurre• 6 years ago

You should have zero fear instilled when pressing any button. The system or process has failed if a single person pressing a button can bring something down unintended. Fix the system/process, don’t “instill fear” onto the person, it’s toxic, plus now you have to make sure any new person on boarded has “fear instilled”, and that’s just hugely unproductive

corobo3• 6 years ago

Most will hide it away because being truthful will hurt current business or future career prospects because people like yourself exist who want everyone shitting themselves at the prospect of being honest.

In a blame free environment you find the underlying issue and fix it. In a blame full environment you cover up the mistake to avoid being fired and some other person does it again later down the line

MaxBarraclough• 6 years ago

You're speaking to the mistake. The comment you're replying to is speaking to the write-up analysing the mistake.

Blog posts analysing real-world mistakes should not be met with beratement.

ClumsyPilot3• 6 years ago

"fear required when working out what decision to make"

People like you keep making the same mistake, creating companies/organisations/industries/societies that run on fear of failure. We've tried it a thousand times, and it never works.

You can't solve crime by making all punishments hearsh death, we've tried that in 1700 in Britain and crimerate was sky high.

This culture gave us disasters in USSR and famine in China.

The only thing that can solve this problem is structural change.

hightekredneck• 6 years ago

Exactly right.

The "comfort" will come from taking responsibility and owning and correcting the problem such that you have confidence it won't happen again.

Platitudes to make someone feel better without action helps nobody.

The fear is a valuable feedback mechanism and shouldn't been ignored. It's there to remind you of the potential consequences of a careless fuckup.

Lots here misunderstood this I think.. clearly the point is not to berate people for making mistakes or to foster a "fear culture" insofar as fear of personal attack but rather to not ignore the internal/personal fear of fucking up because you give a shit.

caspii3• 6 years ago

Thanks

ordu• 6 years ago

I'm appalled at the way some people here receive an honest postmortem of a human fuck-up. The top 3 comments, as I write this, can be summarized as "no, it's your fault and you're stupid for making the fault".

It seems that people annoyed mostly by "complexity gremlins". They are so annoyed, that they miss previous sentence "we’re too tired to figure it out right now." Guys fucked up their system, they restored it the best they could, they tried to figure out what happened, but failed. So they decided to do PR right now, to explain what they know, and to continue the investigation later.

But people see just "complexity gremlins". The lesson learned is do not try any humor in a postmortem. Be as serious, grave, and dull as you can.

ganafagol• 6 years ago

It's good to have a post mortem. But this was not actually a post mortem. They still don't know how it could happen. Essentially, how can they write "We’re too tired to figure it out right now." and right after attempt to answer "What have we learned? Why won’t this happen again?" Well obviously you have not learned the key lesson yet since you don't know what it is! And how can you even dream of claiming to guarantee that it won't happen again before you know the root cause?

Get some sleep, do a thorough investigation, and the results of that are the post mortem that we would like published and where you learn from.

Publishing some premature thoughts without actual insight is not helping anybody. It will just invite the hate that you are seeing in this thread.

rawgabbit2• 6 years ago

For me, this is an example of DevOps being carried too far.

What is to stop developers for checking into Github "drop database; drop table; alter index; create table; create database; alter permission;"? They are automating environment builds and so that is more efficient right? In my career, I have seen a Fortune 100 company's core system down and out for a week because of hubris like this. In large companies, data flows downstream from a core system. When you have to restore from backup, that cascades into restores in all the child systems.

Similarly, I once had to convince a Microsoft Evangelist who was hired into my company, not to redeploy our production database, every-time we had a production deployment. He was a pure developer and did not see any problems of dropping the database, recreating the database, and re-inserting all the data. I argued that a) this would take 10+ hours b) the production database has data going back many years and that the schema/keys/rules/triggers have evolved during that time-- meaning that many of the inserts would fail because they didn't meet the current schema. He was unconvinced but luckily my bosses overruled him.

My bosses were business types and understood accounting. In accounting, once you "post" a transaction to the ledger that becomes permanent. If you need to correct that transaction, then you create a new one that "credits" or corrects the entry. You don't take out the eraser.

bromuro• 6 years ago

I think you should wait 10+ hours to read different kind of comments on HN.

For example, if i open the comments about a “14 hours ago” post, I usually see a top comment about other comments (like yours).

I then feel so out of the loop because i don’t see the “commenters” your are referring too - so the thread that follows seem off topic to me.

throwdbaaway• 6 years ago

The script also unnecessary complicates things. If it just does the equivalent of rake db:drop, this incident wouldn't have happened, since postgres wouldn't allow a database with active connections to be dropped.

glintik• 6 years ago

"at around 10:45pm CET, after a couple of glasses of red wine, we deleted the production database by accident". That's not an accident, guys..

Stop drink and deploy something on production, especially at late evening time.

madsbuch• 6 years ago

Things like these happen, and we should be compassionate towards them.

Often small changes to the structure drastically reduce probability of stuff like this happening.

Eg. we use docker to setup test and dev databases and seed from (processed) dumps. When we need to clean our database, we simply put down the docker container. Ie. we do not need to implement destructive database cleanup eliminating structure that could potentially fail.

Having policies about not accessing production database directly (and allow the extra time for building tooling around that policy), good preview / staging environments, etc. All fail eliminating structure.

restlessbytes• 6 years ago

While I'm very sympathetic to "we accidentally nuked our prod DB" because, let's admit it: we've all been there at some point, I'm also a bit baffled here because I don't think that the problem lies with too much wine, Postgres permissions or scripts on localhosts but the fact that recreating a database by FIRST dropping all tables and THEN recreating them is like deliberately inviting those gremlins in.

But, as I said, that happens and blaming doesn't fix anything, so, for the future:

1. make a temporary backup of your database 2. create tables with new data 3. drop old tables

ing33k• 6 years ago

I run a replicated ClickHouse server setup, Clickhouse uses zookeeper to enable replication. The zookeeper instance was not replicated.it was a single node. The server on which zookeeper was running ran out of hard disk and Clickhouse went into read only mode. Luckily,no data was lost while this happened because we use RabbitMq to store the messages before it gets written to the db. Thanks to RabbitMq's ACK mechanism.

gcc_programmer2• 6 years ago

The maturity of the article is laughable. I'm sure my age is the same as the people who wrote it, but this is unacceptable: dropping databases in prod is a serious issue, not a joke. I think the culture of the company is toxic and not professional at any level. #change-my-mind

azeirah2• 6 years ago

It's one individual's side-project, chill.

gcc_programmer2• 6 years ago

It's not a side project, it's a production database owned by a company... I hope I never have to use products you buils either...

noja• 6 years ago

A function called database_model_create() should not drop something.

Here it would have failed to create the already existing tables and raised an error.

zerr• 6 years ago

It reads like the db was deleted intentionally for the sake of blog post - marketing that is. :)

dschuetz2• 6 years ago

Someone might have copy&pasted it elsewhere and that propagated away. This is why writing code can also be dangerous in open dev. Whoever programmed anything also should be sensible enough to judge their own code whether it could be dangerous in the wild. Once out there (or worse: on stackoverflow) it could wreak havoc.

vox17• 6 years ago

This line's the winner for me : "Thankfully nobody’s job is at risk due to this disaster. The founder is not going to fire the developer – because they are one and the same person."

ClumsyPilot3• 6 years ago

To be fair he could, and least in theory - he could get someone else to do development, for money or equity, for the project and do something else himself.

benhurmarcel• 6 years ago

It's just one guy working in the evening on a side project. There's no revenue, and it runs on $171/month [1]. He's not going to hire anyone.

[1] https://keepthescore.co/blog/posts/monetizing-keepthescore/

nix23• 6 years ago

To all the people who say "that could never happen to me" work less then 5y in the industry. That can happen to anyone anytime.

Remember: You just fix the errors YOU can think of.

majkinetor• 6 years ago

Once it happened to me, and now all scripts in last 10 years have

    if (Env.Name -like '*prod*' ) { then throw }

and similar to all destructive stuff.

ricksharp• 6 years ago

Are you sure it was the production database that was affected?

If you are not sure how a hard coded script that was targeting localhost affected a production database, how do you know you were even viewing the production database as the one dropped?

Maybe you were simply connected to the wrong database server?

I’ve done that many times - where I had an initial “oh no“ moment and then realized I was just looking at the wrong thing, and everything was ok.

I’ve also accidentally deployed a client website with the wrong connection string and it was quite confusing.

In an even more extreme case: I had been deploying a serverless stack to the entirely wrong aws account - I thought I was using an aws named profile and I was actually using the default (which changed when I got a new desktop system). I.e. aws cli uses —profile flag, but serverless cli uses —aws-profile flag. (Thankfully this all happened during development.)

I now have deleted default profiles from my aws config.

jbverschoor• 6 years ago

Why? This is something we’re still trying to figure

Probably the admin has set the hba config to trust localhost. Solution - don't use the same db name in prod jsut to be sure

flurdy• 6 years ago

In one of my first jobs I deleted the last 30 days of our production data.

Shit happens. You learn and try to never repeat it. And share with others so hopefully they learn.

Ps. Don't do knee-jerk late at night quick patches. For example don't stop a database that has run out of disk space, try to migrate the data in memory first... And also do proper backup monitoring, and restores. Having 30 days of 0 byte backups is not that helpful. :)

rafamvc• 6 years ago

A very similar thing happened to living social during their brightest years, but the replication and the backups had failed too. The oldest valid backup was about a week old. It took the whole company offline for 2 days. It took a team of 10 people and some extra consultants to come up with a half backed version of the latest database based on elastic cache instances, redis caches and other "not meant to be a backup" services. It was insane walking in an office that had hundreds of employees and see they all gone while we rebuild this cobbled together db.

At one point someone called it "good enough" and they basically had to honor the customer word if they had purchased something and it wasn't there.

It was a mess.

It was on all major news, and it was really bad press. In the end, they actually had a massive bump in their sales afterwards. Everyone went to checkout their own purchases and ended up buying something else, and the news was like free ads.

https://www.washingtonpost.com/business/capitalbusiness/the-...

info7812• 6 years ago

Why did they not have archive log mode on in production? Losing a db is one thing, but should have only been one hour of data lost.

AdrianB14• 6 years ago

Focus, time, expertise and cost. For a side project with no revenue, cost is a very important factor. The others come with having side projects.

pachico2• 6 years ago

I still remember how many years ago, when someone in my team told me one Friday afternoon "there's not something like 'undo' for 'drop table', right?". He spent the weekend recreating the data.

pachico2• 6 years ago

Yes, Manuel, I'm talking about you! :)

ystad• 6 years ago

Thankfully our database is a managed database from DigitalOcean, which means that DigitalOcean automatically do backups once a day. Do cloud providers provide a smaller window for backup. Are there better ways to reduce the backup window here for DBs? Would love to understand any techniques folks use to minimize the backup window?

minkeymaniac• 6 years ago

That is why we can only access the prod db from a jump box in our shop.... And even then it's just certain people with less privileges than a sysadmin account. No way you can do this accidentally from your laptop then...

jrochkind1• 6 years ago

The lack of the seriousness/professionalism of the postmortem seemed odd to me too. So, okay, what is this site?

KeepTheScore is an online software for scorekeeping. Create your own scoreboard for up to 150 players and start tracking points. It's mostly free and requires no user account.

And also:

Sat Sep 5, 2020, Running Keepthescore.co costs around 171 USD each month, whilst the revenue is close to zero (we do make a little money by building custom scoreboards now and then). This is an unsustainable situation which needs to be fixed – we hope this is understandable! To put it another way: Keepthescore.co needs to start making money to continue to exist.

https://keepthescore.co/blog/posts/monetizing-keepthescore/

So okay, it's basically a hobby site, for a service that most users probably won't really mind losing 7 hours of data, and that has few if any paying customers.

That context makes it make a little bit more sense.

smarx007• 6 years ago

A question to the DBA experts from a developer: is there a way in MySQL and Postgres to configure a log specifically for destructive SQL queries so that it's easier to investigate a situation like this? I.e. to log most queries except for usual SELECT/INSERTs.

Also, @oppositelock pointed out that WAL would contain the destructive query too. How does one remove a single query from a WAL for replay or how does one correctly use WAL to recover after a 23-hour old backup was restored?

Finally, how does one work on the WAL level with managed DBs on AWS or DO if they block SSH access?

fallingfrog• 6 years ago

I once replaced a bunch of customer photos with a picture of Spock as part of a test on my first week on the job.. The dB admin had just overwritten a sales force dev dB from production and a previous developer had hardcoded the IP address of production in the code of a script somewhere..

gregors• 6 years ago

Github did something similar. https://github.blog/2010-11-15-today-s-outage/

aerxes• 6 years ago

This postmortem is incomplete: it fails to address the main three roots of the problem:

1. This business is too flippant with their write-able production access.

2. No user should have DROP DATABASE grants on production.

3. Clearly one of their employees was using a port forward to access production.

cmeacham98• 6 years ago

While several other users have posted takeaways for how to prevent this from happening, I'd be interested in if anybody has an idea of how this happened given the code that was posted?

Presumably, a managed DB service should essentially never be available on `localhost`. Additionally, it would be very weird for `config.DevelopmentConfig` to return the production database credentials.

0kl• 6 years ago

Note that host is hardcoded to localhost. This means it should never connect to any machine other than the developer machine.

Just to help with the postmortem:

1) “localhost” is just a loopback to whatever machine you’re on

2) the user and pw are pulled from config

So someone was running this from the production server or had the production DB mapped to localhost and ran it with a production config for some reason (working with prod data maybe). The hard coding to localhost will only ensure that it works for the machine it’s called on - in this case the prod server.

Things you might do to avoid this in the future include a wide spread of things, the main recommendations I’d have are:

1) only put production artifacts on prod

2) limit developer access to prod data

Best of luck

xupybd• 6 years ago

I don't understand how this happened if localhost is hard coded and the password is different. I don't think they fully understand why this happened. At least enough to prevent it from happening again.

We deleted the production database by accident

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