We scaled PgBouncer to 4x throughput
93 points - today at 3:28 PM
SourceJust use https://github.com/yandex/odyssey :) It's a scalable PgBouncer.
saisrirampur
today at 5:25 PM
We started with the most battle-tested and native option to Postgres, which is PgBouncer and tried tuning it the right way. Also now that long due kinks like support for prepared statements are solved, itβs been working really well. There are many customers scaling well with 10K+ Postgres connections. We will consider other options like odyssey, pgdog in the future!
Side note: Iβm not a big fan of having 10K+ connections on Postgres, 100s are more than enough to scale Postgres well. But thatβs a story for another day. ;)
Fun (semi-related) fact, ClickHouse was originally developed by Yandex :)
Interesting. We run pgbouncer via kubernetes so it was straightforward to make multiple pgbouncer processes on one machine. Also straightforward to get them running on multiple machines, which helps because we run on Azure and they like to cause rolling outages across our fleet via VM maintenance...
saisrirampur
today at 5:20 PM
Ack, makes sense. Iβm very curious on how this affects throughput due to a potential extra network hop from pgbouncer to Postgres. Expecting it to have a minor difference, but still curious.
Was there a disadvantage to using HAProxy + multiple PGBouncer instances?
SO_REUSEPORT[1] pretty much does all we want in kernelspace vs unnecessary userspace hop inbetween. These all run on same VM
1: https://lwn.net/Articles/542629
jauntywundrkind
today at 4:01 PM
This was more for fun than real use, but I greatly enjoyed hacking something similar into rqbit bittorrent client.
I wanted to run an instance of 'rqbit download' per torrent via so_reuseport. When a peer tries to connect, it gets sent to a random instance. So I built a whole rendezvous system, where instances find each other & either proxy data to each other or fd pass the socket to each other directly to get the peer socket to the instance that needs it. It uses postcard rpc to chat between instances.
Clickhouse's so_reuseport rendezvous needs are obviously for a very different, but fun to see some so_reuseport coordination like this (for a much more practical use)!
It'd be really neat to have some kind of general peering protocol that different apps could use. This whole exercise was gratuitous as heck for my application, I don't even really intend to use this, but it was a fun path to walk down. So I don't really know what the broader protocol would really be for, what we would use it for. But it seems like such a cool idea! A shared Turso database would probably be a bit more practical than the rpc system, honestly. Ha.
https://github.com/rektide/rqbit/tree/peering
Article should show the config:
[pgbouncer]
listen_addr = 0.0.0.0
listen_port = 6432
so_reuseport = 1
peer_id = 1
unix_socket_dir = /tmp/pgbouncer1
[peers]
1 = host=/tmp/pgbouncer1
2 = host=/tmp/pgbouncer2
3 = host=/tmp/pgbouncer3
4 = host=/tmp/pgbouncer4