Cargo.toml

[package]
name = "sqlx-nagle"
version = "0.1.0"
edition = "2024"

[dependencies]
anyhow = "1.0.103"
chrono = "0.4.45"
sqlx = { version = "0.9.0", features = ["mysql", "runtime-tokio", "tls-rustls"] }
tokio = { version = "1.52.3", features = ["full"] }

# [patch.crates-io.sqlx]
# git = "https://github.com/dmitryvk/sqlx.git"
# branch = "opt-tcpnodelay"

main.rs

use std::{str::FromStr, time::Instant};

use sqlx::{
    ConnectOptions,
    mysql::{MySqlConnectOptions, MySqlSslMode},
};

#[tokio::main]
async fn main() -> anyhow::Result<()> {
    let options = MySqlConnectOptions::from_str("mysql://...:...@127.0.0.1:13506/...")?
        .ssl_mode(MySqlSslMode::Required);

    for i in 1..10 {
        let start = Instant::now();
        let mut conn = options.connect().await?;
        let _row: Option<(i64,)> = sqlx::query_as("SELECT 1").fetch_optional(&mut conn).await?;
        let duration = start.elapsed();
        println!("{i}: {duration:?}");
    }

    Ok(())
}

stdout

1: 47.614553ms
2: 47.927839ms
3: 46.50919ms
4: 46.086652ms
5: 47.159015ms
6: 54.992702ms
7: 54.220359ms
8: 47.192027ms
9: 47.582144ms

stdout with `[patch.crates-io.sqlx]` uncommented

1: 9.487389ms
2: 5.12714ms
3: 5.251148ms
4: 4.052201ms
5: 4.289836ms
6: 5.130867ms
7: 4.108613ms
8: 4.106108ms
9: 5.223923ms