Manifest — SegmentedArray Fixes & Discussion on Two-Phase Transfers

We started fleshing out the fuzz test harness, then realized that our assumptions around helpers for an empty SegmentedArray were not correct and that we had over-factored out the helper methods.

Rather than relying on our fuzz test to find these bugs, we decided to "do what would make for the most assurance":

1. review the code again to correct our understanding,
2. build up assertions, and then
3. fuzz!

This had a significant result already before the day was done, and the code is now much better for it. We realized that time in development is not considered equal with time in production, because a production fix takes much longer to apply and costs more all-in-all.

We also figured out an ideal type system for converting indexes into counts and doing comparisons between them :-)

See also 3:40 into the stream for a fun discussion on TigerBeetle's two-phase transfer as an accounting primitive, and how TigerBeetle runs at the intersection of accounting books + accounting policy + distributed systems reality.

Видео Manifest — SegmentedArray Fixes & Discussion on Two-Phase Transfers канала TigerBeetle