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Chess.com stopped working on 32bit iPads because 2^31 games have been played

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Re: Chess.com stopped working on 32bit iPads because 2^31 games have been played

#81

Post by fpgaminer »

rdtsc wrote: post #53
cm2187 wrote: post #8

Self-confidence as a programmer is when starting a new project, storing the transaction ID as a long rather than an int...

> Self-confidence as a programmer is when starting a new project, storing the transaction ID as a long rather than an int... uint64_t even Or a UUID as others have suggested. Technically C spec doesn't really say exactly how many bits int, long and long long should be. If you want specific sizes and your code to be somewhat portable use the specific bit sizes to make that clear. There are also types for size-like thi…

> If you want specific sizes

I would go further and say you should _always_ use specific sizes, unless forced otherwise. There's no reason not to.

Re: Chess.com stopped working on 32bit iPads because 2^31 games have been played

#82

Post by justin66 »

davidgerard wrote: post #64
justin66 wrote: post #62

Earlier quoted context omitted.

- Who among us is writing code today worried about how it will be used in 2052? The good programmers who are fortunate enough to be working on software that matters.

In my experience it's not the good systems that stick around - they're cleanly replaceable. It's the quick hacks and bodges that stick around forever.

Well, yeah, I absolutely agree. Replaceability and maintainability go hand in hand in a system. It's a cruel irony that the code that sticks around, often sticks around because it's crap.

(that doesn't stop me from sometimes having a weird admiration for incomprehensible software kept going forever with weird hacks. It's like with movies, sometimes they're so uniquely awful that you have to admire the art of them)

Re: Chess.com stopped working on 32bit iPads because 2^31 games have been played

#83

Post by reformatt »

abalone wrote: post #50

So they probably just need to use longs instead of ints. But I'm curious, if you were really stuck with a 32-bit limit on data types, what's your preferred workaround? I'm thinking I'd add another field that represents a partition. Are there other "tricks"?

If you could only use 32-bit data types, you can get 64-bits from using 2 integers together like a long number. So the right integer would hit the max, start over at 0, and increment the left integer. Then, using this idea you can create a class of numbers that can have however many bits you want by using more ints.

Re: Chess.com stopped working on 32bit iPads because 2^31 games have been played

#85

Post by fpgaminer »

pram wrote: post #55

I recently experienced a nasty bug with BLOB in MySQL. The software vendor was storing a giant json which contained the entire config in a single cell. It ran fine for months, and then when it was restarted it totally broke. Reason was: the json had been truncated the entire time in the database, so it was gone forever. It was only working because it used the config stored in memory on the local system. Nasty!

For those, like my, that didn't recall off the top of their heads: BLOB in MySQL can usually only hold ~64KB.

EDIT: Though I am curious why MySQL doesn't throw an error when you try to store more than 64KB in BLOB?

Re: Chess.com stopped working on 32bit iPads because 2^31 games have been played

#86

Post by ww520 »

chesserik wrote: post #74
windowshopping wrote: post #70

Earlier quoted context omitted.

We can help you understand how and why! Computers set limits internally on how big numbers can be when they're keeping track of stuff. Your developers had given each game a number to identify it. So your first game was #1, the 40th game was #40, and so on. The limit for how big the number could be was a bit over 2 billion, and your players have just now played a bit over 2 billion games, and so that id number suddenl…

Yes - I understand HOW it happened, just not sure WHY. Meaning, I'm not sure what the developer was thinking, and at this point, I'm not going to track down exactly who it was and point fingers. I think everyone has learned enough through this highly interesting bug. It certainly was interesting to see the slack room exploding with theories and debugging. A new iOS client has been submitted to Apple (hurry plz!!!), a…

It's most likely for efficiency and performance reason. 64-bit doubles the storage requirement of 32-bit and would have impact on database's utilization of memory, querying window size, cache, and storage.

Edit: 32 bits worth of games played means about 4 billion games. 4 billion X 4 bytes for 32-bit = 16GB just for the 32-bit ID's. 64-bit ID's would need 32GB for the 4 billion games. I guess memory and storage weren't that cheap back then.

Re: Chess.com stopped working on 32bit iPads because 2^31 games have been played

#87

Post by wongarsu »

wpietri wrote: post #56
justin66 wrote: post #36

Earlier quoted context omitted.

> I sometimes think it would've been better if a few things had visibly failed in January 2000. Having to spend billions of dollars on programmers' goofy means of saving a few bytes of memory is a pretty visible failure.

Nope. Definitely not goofy. My dad was a programmer in the early days. The machines he started on in the 1960s had 8 KB of RAM. Saving a byte then is the equivalent today of saving 1 MB on an 8 GB machine. Multiply that times, say, the thousands of customer orders you're trying to process and the goofy thing would be burning a lot of additional RAM because it might help somebody 35 years later. Who among us is writin…

>Who among us is writing code today worried about how it will be used in 2052?

This decade I knowingly wrote code that will break in 2036 [1]. My supervisor was against investing the time to do it future-proof (he will be retired by 2036), and I have good reason to believe the code will still be around by that time. I don't think I'm the only programmer in that position.

[1] Library specific variant of the y2038 problem https://en.wikipedia.org/wiki/Year_2038_problem

Re: Chess.com stopped working on 32bit iPads because 2^31 games have been played

#88

Post by justin66 »

Retric wrote: post #72
justin66 wrote: post #36

Earlier quoted context omitted.

> I sometimes think it would've been better if a few things had visibly failed in January 2000. Having to spend billions of dollars on programmers' goofy means of saving a few bytes of memory is a pretty visible failure.

It really depends on how much data and how old. My dad's first programming job was initially to mechanically change how variables where stored thus saving 1 and only 1 byte of disk space . Someone ran the numbers and having someone do that for a few months was a net savings. A few years after that he was talking about some relatively minor optimizations that saved a full million dollars worth of hardware costs by del…

Regarding the point I was speaking to: it's undoubtedly true that some of those hacks were initially worthwhile. Keeping them going until the year 2000 was, by that same standard of cost effectiveness, pretty definitely a visible failure.

Re: Chess.com stopped working on 32bit iPads because 2^31 games have been played

#89

Post by DCoder »

pram wrote: post #55

I recently experienced a nasty bug with BLOB in MySQL. The software vendor was storing a giant json which contained the entire config in a single cell. It ran fine for months, and then when it was restarted it totally broke. Reason was: the json had been truncated the entire time in the database, so it was gone forever. It was only working because it used the config stored in memory on the local system. Nasty!

MySQL's silent data truncation is such a nuisance. It's off by default in 5.7, and can be disabled in earlier versions by adding STRICT_ALL_TABLES/STRICT_TRANS_TABLES to sql_mode [1].

I inherited a system where, among other things, the entire response body from a payment gateway callback is saved into a text field using utf8 character set, despite the fact that most of the supported payment gateways send data in iso-8859-x (and indicate the used charset inside the body itself, how's that for a chicken-and-egg problem). Of course when the data gets truncated due to not actually being utf8, nobody notices. Fun times.

[1]: https://dev.mysql.com/doc/refman/5.7/en/sql-mode.html#sql-mo...

Re: Chess.com stopped working on 32bit iPads because 2^31 games have been played

#90

Post by nashashmi »

sbov wrote: post #46
glhaynes wrote: post #34

Earlier quoted context omitted.

Similar to how much effort goes into dealing with things like dangerous strains of bird flu, only to have people complain about how much money was spent on "nothing" when an outbreak doesn't occur.

This is a whole class of problem - I wonder if there's a name for it. More examples include: talking about welfare being unnecessary because no one is starving. Or people on medications stopping because they feel better (while still on them).

A more relevant way of putting it for me: Why do we have to have so many different corporate rules and processes when everything is working anyways?
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