search the ror trac for 'replication' http://dev.rubyonrails.org/ticket/2041
hth -- courtenay On 11/23/05, Robert Cottrell <[EMAIL PROTECTED]> wrote: > I've been thinking about this as well, as our sites are now starting > to push the limits of a single MySQL database. > > I think, however, that the selection of master or slave database has > to persist for the entire page request or you risk inconsistent data > and transactions (even reads within a transaction can have locking > implications). Pages would probably need to be designated as read- > only or read-write and use the same throughout the page serve. > > I was thinking that one way of doing this in a backwards compatible > manner would be specify that certain actions in the controller were > guaranteed to be read only, any other actions would be presumed to > require the master database. An exception could be generated if a > write were attempted with a read-only connection. Maybe something > like this: > > class Entry < ApplicationController > read_only :index, :view > > def index; end > def view; end > def add; end > def delete; end > end > > The read_only attribute could set a thread-local flag that would > cause ActiveRecord::Base#connection to choose either a master or one > of several configured slave databases. > > -Bob. > > > On Nov 23, 2005, at 1:57 PM, Ryan Carver wrote: > > > Hi all, > > > > We're thinking of moving mysql to master/slave. What I'd like to do > > is configure a reader and writer db in database.yml, then > > AR::Base#create and AR::Base#update would use the writer > > connection. Initially we'd just do 1 reader db. A more complex > > solution might configure more and have each fcgi choose one at > > random at startup. > > > > If internally AR had the concept of reader_connection and > > writer_connection, it would be easy to build plugins around this. > > > > Seems like this would be pretty easy to do, but are there > > complications I'm ignoring? Has anyone already done this? Good? Bad? > > > > - Ryan > > > > _______________________________________________ > > Rails-core mailing list > > [EMAIL PROTECTED] > > http://lists.rubyonrails.org/mailman/listinfo/rails-core > > _______________________________________________ > Rails-core mailing list > [EMAIL PROTECTED] > http://lists.rubyonrails.org/mailman/listinfo/rails-core > _______________________________________________ Rails-core mailing list [EMAIL PROTECTED] http://lists.rubyonrails.org/mailman/listinfo/rails-core
