Topic

In-Memory Database Persistence

The techniques by which in-memory data stores write point-in-time state to disk, commonly by forking a child process so the parent can keep serving traffic.

Current clusters

build1 publisher

Dirtying all of a 64 GB heap during a fork snapshot costs 16.8 million page faults

A dev.to walkthrough traces fork() from the cleared write bit in every PTE down to do_wp_page, where a refcount check decides whether a snapshot window costs a 4 KiB copy for each dirtied page or nothing at all.

Publishers:dev.to

Reality

Evidence48
Adoption: Insufficient
Hype gap+35
Incentives20
Confidence46