r2d2

A generic connection pool for Rust.

Documentation

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.

A (possibly not exhaustive) list of adaptors for different backends:

Backend | Adaptor Crate ------------------------------------------------------------------- | ------------- rust-postgres | r2d2-postgres redis-rs | r2d2-redis rust-mysql-simple | r2d2-mysql rusqlite | r2d2-sqlite rusted-cypher | r2d2-cypher diesel | r2d2-diesel

Example

Using an imaginary "foodb" database. ```rust use std::thread;

extern crate r2d2; extern crate r2d2_foodb;

fn main() { let config = r2d2::Config::builder() .poolsize(15) .errorhandler(Box::new(r2d2::LoggingErrorHandler)) .build(); let manager = r2d2_foodb::FooConnectionManager::new("localhost:1234");

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

for _ in 0..20 {
    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.
    })
}

} ```