Multiple database connection

Question

I'm trying to understand the best way to get the connection to my databases.

At the moment I've got a method which parses the URL (depending on the URL called the application has to connect to a different database, like customer1.example.com will connect to the customer1 database) and calls

ActiveRecord::Base.establish_connection(conn_string)

where conn_string contains the name of the database.

This method (set_db) is called with a

before_filter :set_db

in my Application controller, so basically for each request I get, the URL is parsed and the application try to do an establish_connection.

I was wondering if I can have a connection pool somewhere....do you have any suggestion about that? Is it better to have a Singleton which keep all the connections made and gives back the right one?

Thanks! Roberto

Answer 1

Are the databases on the same server?

I have a application where some of the model objects are from one database and others are from a different database. I override the table_name function to specify the database. Won't work if they are different servers but will work for different databases in the same server.

class xx < ActiveRecord.base

def self.table_name
  "otherdatabase.table"
end

It also looks like database pooling may be on the way for an upcomming version of rails.

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