This is the only comment worth a thing here. Unless mongodb causes irrevocable data loss, eventual consistency is easily mitigated using an accounting service. I have seen one of them at work. Transaction amount comes in, it is compared with initial value and the session is kept open until the quantity is fulfilled. If there is a timeout, secondary systems try to recover or alert. Recovery can even deduct overfills or complete fills.
This seems ridiculously complicated and unnecessary for something that should be as easy as having a proper RDMS that is ACID compliant. I guess now we have one additional reason why banking has stagnated for so long.
Just in case you (or someone else) don't know why you are being downvoted, I'll give you a few reasons:
- Banks have to put these double-checking and reporting systems in place because the law mandates them to. No amount of ACID compliance in your database is freeing you from that.
- These requirements are not stupid either: assuming you had a perfect system with perfect ACID compliance and 0 bugs ever (which we all know is impossible), a random hardware failure (or cosmic ray) can flip a bit somewhere and you are screwed.
- Your comment reads as extremely condescending, which is never good to get your point across.
- Not only that, but you dismissed the work of some of the best people money can buy in two sentences with 0 rationale. Next time you think you know better than an entire extremely well funded industry, think again, and again, and again. If you are still convinced you know better, please open shop because if you are right you'll not just make yourself the next self-made billionaire, but also probably improve our lives in the process.
This comment gives me hope that there are at least some decent people on Hacker News.
Every time I read an article here I am put off from participating further because the comments are usually filled with toxic spew from peacock fan boys Who think they know better.
It is complicated, but necessary. You will get to the ridiculous part once you realize that executing brokers don't care about your acid guarantees or whatever.
