4 ms·

Here's my write-up of how I learned about this phenomenon in a specific software system: https://www.solipsys.co.uk/new/GracefulDegradation.html?UI10HNa https:

Here's my write-up of how I learned about this phenomenon in a specific software system: https://www.solipsys.co.uk/new/GracefulDegradation.html?UI10HNa https://www.solipsys.co.uk/new/GracefulDegradation.html?UI10... In all the systems I've been involved with since, "Discontinuous Behaviour" is a failure mode we've explicitly analysed, and "Graceful Degradation" is a technique we've often implemented. In case people want to discuss that separately I've submitted it here: https://news.ycombinator.com/item?id=28478909 https://news.ycombinator.com/item?id=28478909

thaumasiotes 5y ago
I feel like the "graceful degradation" writeup is incomplete. The obvious solution -- to me -- would be to have the tills continue operating as normal while their queue is full, but stop trying to write to the queue. This would allow you to sell as many items as people desire to buy, but you lose the ability to keep track electronically of what's been sold. The ideal solution presented here is instead that the tills should bottleneck the customers so that they collectively can't buy more items than the central computer is capable of logging in amortized real time. This preserves the ability to keep electronic track of everything the store sells. But it does it by preventing the store from selling its inventory to customers! Instead of a loss in real-time recordkeeping, we have a hard cap on the amount of money the store can earn during the Christmas season. And the reason we've put the cap in place is that otherwise we'd blow right past it! That solution is so anomalous-seeming that I want to see a discussion of what exactly the store's goals are, and why refusing to sell your inventory to customers in December is a good idea for a retail store.
- TeMPOraL 5y ago
  It makes sense if: - Reconciling electronic inventory numbers with the real ones will cost more than the store will earn from uncapping the sales, and/or - There's a potential legal/tax risk involved with having stock numbers be bad, and/or - There's a risk of losing customers and reputation when stock of a product physically runs out while the tracking system isn't aware of this, and a bunch of customers have to have their orders cancelled because there's nothing to fulfill them with.
  - thaumasiotes 5y ago
    It might make sense. But it probably doesn't. Without a discussion between the store and the IT guy, this looks like the store having a problem of "we want to sell our items, but the till isn't letting us" and the IT guy having a problem of "when the till locks up, the store's problem is obviously my fault", and the IT guy solving his personal problem at the store's expense because the store doesn't know any better.
    - ColinWright 5y ago
      I feel like you're not giving enough credit to a professional programmer.

thaumasiotes 5y ago

I feel like the "graceful degradation" writeup is incomplete. The obvious solution -- to me -- would be to have the tills continue operating as normal while their queue is full, but stop trying to write to the queue. This would allow you to sell as many items as people desire to buy, but you lose the ability to keep track electronically of what's been sold. The ideal solution presented here is instead that the tills should bottleneck the customers so that they collectively can't buy more items than the central computer is capable of logging in amortized real time. This preserves the ability to keep electronic track of everything the store sells. But it does it by preventing the store from selling its inventory to customers! Instead of a loss in real-time recordkeeping, we have a hard cap on the amount of money the store can earn during the Christmas season. And the reason we've put the cap in place is that otherwise we'd blow right past it! That solution is so anomalous-seeming that I want to see a discussion of what exactly the store's goals are, and why refusing to sell your inventory to customers in December is a good idea for a retail store.

TeMPOraL 5y ago
It makes sense if: - Reconciling electronic inventory numbers with the real ones will cost more than the store will earn from uncapping the sales, and/or - There's a potential legal/tax risk involved with having stock numbers be bad, and/or - There's a risk of losing customers and reputation when stock of a product physically runs out while the tracking system isn't aware of this, and a bunch of customers have to have their orders cancelled because there's nothing to fulfill them with.
- thaumasiotes 5y ago
  It might make sense. But it probably doesn't. Without a discussion between the store and the IT guy, this looks like the store having a problem of "we want to sell our items, but the till isn't letting us" and the IT guy having a problem of "when the till locks up, the store's problem is obviously my fault", and the IT guy solving his personal problem at the store's expense because the store doesn't know any better.
  - ColinWright 5y ago
    I feel like you're not giving enough credit to a professional programmer.