"throw er; // Unhandled 'error' event" when authenticate to a disable server.

I have many databases and want to connect them simultaneously in my application. Some of them may be disable at some moment. When I use the “sequelize.authenticate” command to connect and save them to the variable “sequelizes” some of them connect errors. I use async await and try to catch but finally loop still get the error.

What are you doing?

var sequelizes = [];

const getSequelize = async (server) => {

    let sequelize = new Sequelize({
        database: server.database,
        username: server.username,
        password: server.password,
        host: server.host,
        port: server.port ,
        dialect: "mssql",
        logging: false,
        // operatorsAliases: false,
        define: {
            freezeTableName: true,
            timestamps: false
        },
        dialectOptions: {
            encrypt: true,
            requestTimeout: 200000
        },
    });

    try {
        await sequelize.authenticate();
        console.log('Connected to ' + server.name);
        return [null, sequelize];
    } catch (err) {
        return [err];
    }
}

for (const server of servers) {
        const [err, sequelize] = await getSequelize(server);
        if (err) {
            console.log(err.message);
            continue;
        }
        sequelizes.push(sequelize);
}

What do you expect to happen?

events.js:167 throw er; // Unhandled ‘error’ event ^ ConnectionError: Connection lost - connect ETIMEDOUT xxxxx:xxx at ConnectionError (/…/node_modules/tedious/lib/errors.js:13:12) at Connection.socketError (/…/node_modules/tedious/lib/connection.js:1151:26) at Connector.execute (/…/node_modules/tedious/lib/connection.js:988:21) at Socket.onError (/…/node_modules/tedious/lib/connector.js:30:7) at Socket.emit (events.js:182:13) at emitErrorNT (internal/streams/destroy.js:82:8) at emitErrorAndCloseNT (internal/streams/destroy.js:50:3) at process._tickCallback (internal/process/next_tick.js:63:19) Emitted ‘error’ event at: at Connection.socketError (/…/node_modules/tedious/lib/connection.js:1151:12) at Connector.execute (/…/node_modules/tedious/lib/connection.js:988:21) [… lines matching original stack trace …] at process._tickCallback (internal/process/next_tick.js:63:19)

What is actually happening?

Dialect: mssql Dialect version: tedious@5.0.3 Database version: SQL Server 2014 Sequelize version: sequelize@5.1.0

[sushantdhiman]

🎉 This issue has been resolved in version 5.3.5 🎉

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

Your semantic-release bot 📦🚀

[sushantdhiman]

Duplicate of https://github.com/sequelize/sequelize/issues/10406