A full-featured connection pool, designed for asynchronous connections(using tokio). Originally based onr2d2.

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

bb8 is agnostic to the connection type it is managing. Implementors of theManageConnection trait provide the database-specific logic to create andcheck the health of connections.

§Example

Using an imaginary “foodb” database.

#[tokio::main]async fnmain() {letmanager = bb8_foodb::FooConnectionManager::new("localhost:1234");letpool = bb8::Pool::builder().build(manager).await.unwrap();for _ in0..20{letpool = pool.clone();        tokio::spawn(async move{letconn = pool.get().await.unwrap();// use the connection            // it will be returned to the pool when it falls out of scope.});    }}