benjojo.co.uk

benjojo posted 11 Oct 2025 21:08 +0000

Me setting up corp XMPP server a few months ago, noticing this in the config file

  ##   ## Mnesia is limited to 2GB, better to use an SQL backend
  ##   ## For small servers SQLite is a good fit and is very easy
  ##   ## to configure. Uncomment this when you have SQL configured:

You will never guess what Ben decided to defer until now

tom scott says "That was a problem for future me, and now I am future me"

29821632@noc.social replied 12 Oct 2025 02:18 +0000
in reply to: https://noc.social/users/29821632/statuses/115358781970203527

@benjojo
I loved doing that unified comms internal DB integration dev work. Call coming in to a user's desktop SIP handset, quick callback function to local intranet and render XML for phone screen with incoming caller detail So good!

benjojo replied 13 Oct 2025 09:53 +0000
in reply to: https://noc.social/users/29821632/statuses/115358781970203527

@29821632 Nice, yeah ejabberd is a bit of a hulk of a application, kinda like a messaging version of ceph.

I moved all of bgp.tools's internal notifications/message streams (basically system->ben comms) to XMPP, because using a 3rd party for it didn't make sense, also doenst align with my goal of getting to offer a "0% USA data involvement" type product

benjojo replied 11 Oct 2025 21:09 +0000
in reply to: https://benjojo.co.uk/u/benjojo/h/382763MxkNl47c1fBj

Mnesia in ejabberd is weird, like a 2GB Mnesia history file is only a 400~ MB sqlite file (unless I really fucked something up), how is mnesia this bad at disk storage

tef@mastodon.social replied 11 Oct 2025 21:18 +0000
in reply to: https://benjojo.co.uk/u/benjojo/h/FRm57Q2rvc559s5tJp

@benjojo guessing it's copy on write database

benjojo replied 11 Oct 2025 21:21 +0000
in reply to: https://mastodon.social/users/tef/statuses/115357615922274926

@tef yeah and I assume because it's index'd for a bunch of ejabberd reasons, it's more index than data

joew@hachyderm.io replied 11 Oct 2025 21:16 +0000
in reply to: https://benjojo.co.uk/u/benjojo/h/FRm57Q2rvc559s5tJp

@benjojo mnesia is meant to be distributed and store Erlang terms (objects) so it's doing something very different from sqlite. I haven't been in the Erlang scene in years but I recall everyone running into problems with it.