Rails: How to split write/read query across master/slave databases.

My website has a very heavy read traffic than write traffic.To improve the performance of my website i have decided to go with master/slave database configuration.

while searching on the internet about master/slave configuration for rails i came across the octopusgem. This gem is very nice and provide the great interface for distributing query across different master and slave servers.

But the issue is that my rails application is very big and if i use octopus gem then i can’t go though a millions of source code line to change the query distribution(sending read query to slave server and write query to master server) across master and slave servers.MySQL Proxy seems to be a great way to resolve this issue but since it is in alpha version i don’t want to use it.

So my question is what is the best way to split read/write query across master/slave server?? is it possible to split read/write query without using any gems in rails??