The Smart Router: How Your API Becomes a Traffic Director

function getShardForUser(userId) {
  if (userId >= 1 && userId <= 500000) {
    return 'shard-1.<TopicPreview slug="database">database</TopicPreview>.com';
  } else if (userId >= 500001 && userId <= 1000000) {
    return 'shard-2.database.com';
  }
}

const userShard = getShardForUser(userId);
const userData = await userShard.query('SELECT * FROM users WHERE id = ?', [userId]);

function getShardForUser(userId) {
  if (userId >= 1 && userId <= 500000) {
    return 'shard-1.<TopicPreview slug="database">database</TopicPreview>.com';
  } else if (userId >= 500001 && userId <= 1000000) {
    return 'shard-2.database.com';
  }
}

const userShard = getShardForUser(userId);
const userData = await userShard.query('SELECT * FROM users WHERE id = ?', [userId]);