Hi all, Building on that, I made Postgres run in the browser using a x86 JavaScript emulator, with ZeroFS mounted in that vm through vsock-virtio that channels back to a 9P websocket wrapper: https://www.zerofs.net/postgresql-in-the-browser
Best, Pierre On Mon, Feb 16, 2026, at 12:06, Pierre Barre wrote: > Hi all, > > Circling back on this thread, ZeroFS now supports placing its WAL on > local storage (or something like S3 Express One Zone). ZeroFS wal is > sub-gigabyte and just there to handle frequent syncs, it doesn't act as > writeback caching. > > Here are pgbench results with synchronous_commit = on, WAL on local > NVMe, on a 6-core / 32GB RAM machine with a 4 Gb/s pipe: > > $ pgbench -c 100 -T 100 --protocol=prepared > > transaction type: <builtin: TPC-B (sort of)> > scaling factor: 100 > query mode: prepared > number of clients: 100 > number of threads: 1 > duration: 100 s > number of transactions actually processed: 1,578,675 > number of failed transactions: 0 (0.000%) > latency average = 6.312 ms > tps = 15,843 (without initial connection time) > > Best, > Pierre > > On Fri, Jul 25, 2025, at 00:03, Jeff Ross wrote: >> On 7/24/25 13:50, Pierre Barre wrote: >> >>> It’s not “safe” or “unsafe”, there’s mountains of valid workloads which >>> don’t require synchronous_commit. Synchronous_commit don’t make your system >>> automatically safe either, and if that’s a requirement, there’s many >>> workarounds, as you suggested, it certainly doesn’t make the setup useless. >>> >>> Best, >>> Pierre >>> >>> On Thu, Jul 24, 2025, at 21:44, Nico Williams wrote: >>>> On Fri, Jul 18, 2025 at 12:57:39PM +0200, Pierre Barre wrote: >>>>> - Postgres configured accordingly memory-wise as well as with >>>>> synchronous_commit = off, wal_init_zero = off and wal_recycle = off. >>>> Bingo. That's why it's fast (synchronous_commit = off). It's also why >>>> it's not safe _unless_ you have a local, fast, persistent ZIL device >>>> (which I assume you don't). >>>> >>>> Nico >>>> -- >> This then begs the obvious question of how fast is this with >> synchronous_commit = on?
