A generic connection pool, designed for asynchronous tokio-based connections This is an asynchronous tokio-based version of r2d2.

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.

bb8 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.

Example

Using an imaginary "foodb" database.

use bb8;
use bb8_foodb;

#[tokio::main]
async fn main() {
let manager = bb8_foodb::FooConnectionManager::new("localhost:1234");
let pool = bb8::Pool::builder().build(manager).await.unwrap();

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