Could someone enlighten me, how Exposed offers reader/writer node splitting, and if there are any re...

# exposed

[Dio]

Could someone enlighten me, how Exposed offers reader/writer node splitting, and if there are any recommended practices for handling this efficiently?

[spand]

If you mean writes go to one database and reads to another then it doesnt. You need to do it manually by passing an explicit Database to the transaction function

[Dio]

...That's so sad.
I used sequelize that support automatically depends on query type(select or insert).
select query goes to reader node,
insert query goes to writer node.

const sequelize = new Sequelize('database', null, null, {
  dialect: 'mysql',
  port: 3306,
  replication: {
    read: [
      { host: '8.8.8.8', username: 'read-1-username', password: process.env.READ_DB_1_PW },
      { host: '9.9.9.9', username: 'read-2-username', password: process.env.READ_DB_2_PW }
    ],
    write: { host: '1.1.1.1', username: 'write-username', password: process.env.WRITE_DB_PW }
  },
  pool: { // If you want to override the options used for the read/write pool you can do so here
    max: 20,
    idle: 30000
  },
})

[spand]

I dont really see much need for this in the framework? Its just something like:

transaction(masterDb) {
 // DO stuff
}
transaction(readDb) {
 // Do stuff
}

You can even get the read pool by:

transaction(masterDb) {
 // DO stuff
}
transaction(readDbList.random()) {
 // Do stuff
}

[spand]

Then its explicit without violating the transaction and isolation level guarantees of the database

[Dio]

I somewhat agree with your opinion, too.
But, manual is manual, you know 😹
Do you know any github repo using similar mothod?

[spand]

No but havent really looked outside exposed

[Arjan van Wieringen]

Just make function “write { … }” and “read { … }” and it is more explicit. Otherwise make a custom implementation for the Connection that delegates based on the action to inner Connection.

I believe that is how Sequalize does it.

[Arjan van Wieringen]

Actually…. Hikari supports this and I think you can just use the HikariPool for this

[spand]

Can you link to Hikari documentation of this ?

[Arjan van Wieringen]

I am searching but only finding obscure GitHub issues… so maybe not the best route

[Dio]

Does HikariCP supports this function?