r2d2 0.6.0

A generic connection pool


A generic connection pool for Rust.

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Opening a new database connection every time one is needed is both inefficient and can lead to resource exhaustion under high traffic conditions. A connection pool maintains a set of open connections to a database, handing them out for repeated use.

r2d2 is agnostic to the connection type it is managing. Implementors of the ManageConnection trait provide the database-specific logic to create and check the health of connections.

The r2d2-postgres crate provides a ManageConnection implementation for rust-postgres.


Using an imaginary "foodb" database.

use std::thread;

extern crate r2d2;
extern crate r2d2_foodb;

fn main() {
    let config = r2d2::Config::builder()
    let manager = r2d2_foodb::FooConnectionManager::new("localhost:1234");

    let pool = r2d2::Pool::new(config, manager).unwrap();

    for _ in 0..20i32 {
        let pool = pool.clone();
        thread::spawn(move || {
            let conn = pool.get().unwrap();
            // use the connection
            // it will be returned to the pool when it falls out of scope.