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by empthought 1328 days ago
Right, there are failure modes that have to be tested and accounted for, and one of them is the state being inconsistent after a shutdown.

The previous poster seemed to advocate for not thinking of this as a failure mode at all but rather normal operation, which I just don’t see as true.
2 comments
tokenrove 1328 days ago
This paper was influential with regards this idea: https://www.usenix.org/conference/hotos-ix/crash-only-softwa...

I don't think it's that unusual, but obviously there are tradeoffs.

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bravetraveler 1328 days ago
Totally, it's certifiably untrue!

Take the InnoDB storage engine in MySQL/MariaDB for example.

For performance (and likely other) reasons, this file only grows. It never shrinks... it will only go to 0 or grow.

The DB (or individual tables, depending on config) have to be truncated/emptied to reclaim those blocks.

Stop it uncleanly and there's a good chance you'll have to sacrifice a considerable amount of the data just to get the engine to start

This and countless other things have to make consistency trade-offs. While everything could be written to only operate atomically, it will also slow to a crawl.

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