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The 32-Bit Dog Ate 16 Million Kids' CS Homework (code.org)
"Any student progress from 9:19 to 10:33 a.m. on Friday was not saved..." explained the embarrassed CTO of the educational non-profit Code.org, "and unfortunately cannot be recovered."
Slashdot reader theodp writes:
Code.org CTO Jeremy Stone gave the kids an impromptu lesson on the powers of two with his explanation of why The Cloud ate their homework. "The way we store student coding activity is in a table that until today had a 32-bit index... The database table could only store 4 billion rows of coding activity information [and] we didn't realize we were running up to the limit, and the table got full. We have now made a new student activity table that is storing progress by students. With the new table, we are switching to a 64-bit index which will hold up to 18 quintillion rows of information.
The issue also took the site offline, temporarily making the work of 16 million K-12 students who have used the nonprofit's Code Studio disappear. "On the plus side, this new table will be able to store student coding information for millions of years," explains the site's CTO. But besides Friday's missing saves, "On the down side, until we've moved everything over to the new table, some students' code from before today may temporarily not appear, so please be patient with us as we fix it."
The issue also took the site offline, temporarily making the work of 16 million K-12 students who have used the nonprofit's Code Studio disappear. "On the plus side, this new table will be able to store student coding information for millions of years," explains the site's CTO. But besides Friday's missing saves, "On the down side, until we've moved everything over to the new table, some students' code from before today may temporarily not appear, so please be patient with us as we fix it."
At least there was a back-up... Or not... Not even a 24-hour transaction log... Or not... Way to go code.org... set that example...
Don't trust the cloud as the only place you store your work.
Consider this a real-world lesson for our youth in the ways that design choices can have unanticipated effects on implementation, manageability and viability of software in the long haul. For extra credit, the kids that are affected should be encouraged to explore what they could have done to mitigate the risk caused by some grown-up's oversight.
It is no surprise to me that the ones creating and operating this platform are just as incompetent as the "graduates" they produce. Mediocrity breeds mediocrity...
Most ACs are not even worth the keystrokes to insult them. Be generically insulted by this and ignored otherwise.
"The way we store student coding activity is in a table that until today had a 32-bit index... The database table could only store 4 billion rows of coding activity information
if it can only store four billion rows, it isnt "the cloud." its just a KVM instance running on a shared hosting facility then, isnt it.
we didn't realize we were running up to the limit, and the table got full.
so not only were you incapable of scaling your infrastructure or your program to handle four billion rows --something every sysadmin on the planet is capable of-- you weren't even competent enough to set up monitoring for it.
We have now made a new student activity table that is storing progress by students.
the ones that lost all their data dont care. the students will leave to try something else, the educators will fall back on lesson plans that werent written by a corporate think tank, and your 'hour of code' will remain just another hour of minecraft in a kids life.
With the new table, we are switching to a 64-bit index which will hold up to 18 quintillion rows of information.
you dont get it. no one fucking cares about your SQL table limits but you, and youre oblivious to the fact that a table with eighteen quintillion rows would never load. code.org will be no different than the spanish or french class in a kids life. a fractional percentage of them will actually go on to use it as a career.
Good people go to bed earlier.
Thank you for teaching the kids the importance of taking responsibility and being honest and open about your mistakes. It's okay to make mistakes as long as we learn from them. Too many people today are afraid of making mistakes and cover them up.
What sort of DBMS are they using that doesn't notify the admin when a table is nearly full? What sort of client are they using that doesn't tell the user when an attempt to write to a DB fails?
If God forks the Universe every time you roll a die, he'd better have a damned good memory.
Code.org CTO Jeremy Stone gave the kids an impromptu lesson on the powers of two with his explanation of why The Cloud ate their homework. "The way we store student coding activity is in a table that until today had a 32-bit index... The database table could only store 4 billion rows of coding activity information [and] we didn't realize we were running up to the limit, and the table got full. We have now made a new student activity table that is storing progress by students. With the new table, we are switching to a 64-bit index which will hold up to 18 quintillion rows of information.
The of seeing a programming education site using 32-bit indexes without any form of index space monitoring is both hilarious and surreal.
Who the hell runs a cloud-based, massively accessible operation with 32-bit indexes? And who the hell runs a production system without database monitoring?
Are you kidding or just have no memory of the past? Sites were incredibly fragile from before. Outages were the norm and you could take down most weak terribly written PHP sites by sneezing at them the wrong way. Maybe you haven't been here long, but we used to have this thing called "Slashdotting" which would take websites down just by being linked to by this webpage. Nothing had any ability to scale and of it did 99â... of the time that hardware was wildly over provisioned.
This has nothing to do with your "hur Hur millennials" bullshit. 32 bit and 64 bit numbers, and problems with picking the right one had been around since the beginning of time. The person that picked 32 bit instead of 64 bit was more likely to be some grizzly old-timer used to drive and memory space being the main constraint. The evil millennial characatur you hate so much would have made it 128 bit and wasted all that space because in this day and age, why the fuck not?
But starting with the assumption "4 billion is enough" when some people have more than 4bn in their bank account
Yep, I should bog down my computer processes because someone else is rich. Incidentally how many bits does it take to represent the number 4bn? While we're at it do you realise that the number of planets that humans have colonised is 1? Let's build a database with a 25 year life expectancy, how many bits would you assign to the index? 64bits? Your approach is the reason computers are frigging slow. It's the reason why I wait for ages to open up Chrome on a Quad 1.4Ghz Snapdragon.
How about instead of just blindly wasting resources you actually learn about statements of requirements and project scopes.
Supercomputer architectures did this a long time ago, translating and assuming everything is 128-bit so that you never have to worry about a limit.
Didn't you just say we should use 64bit for everything by default?
Why does it take so long for basics like web servers and databases to get there? 64-bit by default, MINIMUM.
No thanks. I'll target 8bit minimum and scale up as needed.