Pony’s Postgres Driver Grows Up
Pony has had a Postgres driver since 2023. It didn’t do much for most of those three years. That’s been changing over the last couple of months.
Libraries¶
Pony Gets a Template Engine
If you’ve been following along, you know the story. Lori for networking. Stallion for HTTP. JSON back in the standard library. Pony’s web development stack is coming together piece by piece. But a web stack that only speaks JSON is an API server with aspirations. At some point, someone is going to want an actual page.
ponylang/templates handles that.
Pony Gets a New JSON Library
For the first time in three years, Pony has a json package in its standard library. And this one has some tricks the old one never did.
Stallion: An HTTP Server Built Different
Last week I wrote about lori and the architecture behind Pony’s new networking stack. The short version: your actor is the connection, the protocol machinery is a class you own, no hidden internal actors between you and the socket. If you haven’t read that post, go do that first. Everything here builds on it.
Stallion is an HTTP/1.1 server built on lori. Red has been running benchmarks comparing it against the old http_server package. Here’s what he found, using 50 concurrent connections:
16-byte response body:
| Metric | http_server | stallion |
|---|---|---|
| Requests/s | 441,570 | 710,416 |
| 50% Latency | 106µs | 49µs |
| 75% Latency | 125µs | 84µs |
| 90% Latency | 151µs | 97µs |
| 99% Latency | 1.89ms | 1.45ms |
| Transfer/s | 34.11MB/s | 54.88MB/s |
100KB response body:
| Metric | http_server | stallion |
|---|---|---|
| Requests/s | 160,052 | 192,069 |
| 50% Latency | 254µs | 211µs |
| 75% Latency | 375µs | 315µs |
| 90% Latency | 0.97ms | 0.9ms |
| 99% Latency | 3.07ms | 2.69ms |
| Transfer/s | 15.27GB/s | 18.33GB/s |
A few caveats. These numbers only mean something relative to each other. The server and the wrk client were running on the same machine over localhost with keep-alive enabled, so don’t go comparing them to your favorite web framework’s benchmarks. And this is actually the best-case matchup for the old stack. The benchmark is dead simple. Turn off keep-alive and most of the difference disappears because socket open/close overhead dominates everything else.
Pony Networking, Take Two
Pony’s standard library has a networking package. It works. If you’re writing a simple TCP server or client, it’ll get you there. But if you’ve ever tried to build something serious on top of it, something with real protocol logic, backpressure that you control, or TLS upgrades mid-connection, you know where the walls are.
I hit those walls years ago at Wallaroo. We ended up forking the standard library’s TCP code and writing our own. That experience is where lori came from.