Crash-only confidence, part 1: from random kills to exact boundaries
A crash test that cannot explain itself is mostly theater.
aalhour
notes on software, systems, books, and curiosity.
Latest posts
Making the on-disk state real: Sorted-String Tables (SSTables)
Files are easy; files you can trust, inspect, and recover from are the real step.
The Memtable: where writes go to wait
Before the disk gets involved, memory has to learn the rules.
The syscall I forgot: directory fsync
Sometimes the missing durability bug is one directory above where you were looking.
Durability is a promise you can't hand-wave: Write-Ahead Log (WAL)
Once bytes leave your process, the comforting story gets complicated.