Laravel

Laravel has built-in read/write splitting for database connections.

Read replica routing

Set up read and write connections in config/database.php, pointing both at halephant with different users:

config/database.php

'pgsql' => [
    'read' => [
        'username' => 'myapp_ro',
    ],
    'write' => [
        'username' => 'myapp',
    ],
    'host' => 'halephant',
    'port' => 6432,
    'database' => 'myapp',
    'password' => '...',
    'sslmode' => 'disable',
    'sticky' => true,
],

Laravel sends SELECT queries to the read connection and writes to the write connection. The sticky option makes sure reads after a write in the same request go through the write connection, avoiding stale reads.

Laravel doesn't send BEGIN READ ONLY. The separate user approach lets halephant handle routing. See the read replica guide for halephant configuration.