sequelize/sequelize

# Connection Pool

If you're connecting to the database from a single process, you should create only one Sequelize instance. Sequelize will set up a connection pool on initialization. This connection pool can be configured through the constructor's `options` parameter (using `options.pool`), as is shown in the following example:

```js
const sequelize = new Sequelize(/* ... */, {
  // ...
  pool: {
    max: 5,
    min: 0,
    acquire: 30000,
    idle: 10000
  }
});
```

Learn more in the [API Reference for the Sequelize constructor](../class/lib/sequelize.js~Sequelize.html#instance-constructor-constructor). If you're connecting to the database from multiple processes, you'll have to create one instance per process, but each instance should have a maximum connection pool size of such that the total maximum size is respected. For example, if you want a max connection pool size of 90 and you have three processes, the Sequelize instance of each process should have a max connection pool size of 30.