how to keep alive when the mysql connect timeout?

[heliping]

I use mysql for database, when the connect timeout, the panic will stop the main.
Actually, the database connection is not so important, I want to main can alive even the connection is lost.
Is there any solution?

let  pool:Pool<MySql> = db::db_init().await.expect("PoolTimedOut");
     info!("Starting server...");
    HttpServer::new(move || {
        App::new()
            .app_data(web::Data::new(pool.clone()))
            .service(web::scope("/api/v1").service(
                web::resource("/newc/unparsed").route(web::post().to(controllers::index::index)),
            ))
    })
    .bind(("0.0.0.0", 9080))?
    .run()
    .await

error info

thread 'main' panicked at 'PoolTimedOut: PoolTimedOut', src/router/router.rs:12:49
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

[fakeshadow]

Then just don't panic and handle the error?

[heliping]

How to catch the error when database lost?
like when error, donot use app_data?

  let  pool:Pool<MySql> = db::db_init().await.expect("PoolTimedOut");
 /*   match db::db_init().await {
        Ok(p) => {pool= p},
        Err(e) =>{error!("{:?}", e); } 
        }  */
    info!("Starting server...");
    HttpServer::new(move || {
        App::new()
            .app_data(web::Data::new(pool.clone()))  ----> neednot run!
            .service(web::scope("/api/v1").service(
                web::resource("/newc/unparsed").route(web::post().to(controllers::index::index)),
            ))
    })

[heliping]

I want to fulfill this:
when mysql ok ---> add the connect ---> use app_data;
when mysql fail ----> logging ----> not use app_data.

[fakeshadow]

#[derive(Clone)]
struct DbPool {
    pool: Option<SqlPool>
}

impl DbPool {
    async fn init() -> Self {
        let pool = db::db_init().await {
            Ok(ppool => Some(pool),
            Err(e) => {
                error!("{:?}", e); 
                None
            };
        Self { pool } 
    }

    fn try_get(&self) -> Option<&SqlPool> {
        self.pool.as_deref()
    }
}

Use Option and Result type to represent a possible or branched on error type.