Apparently when using the Octopus gem to do Postgres replication everything should be plug and play. However I can't seem to find what I'm doing wrong.
This is my config/shards.yml
octopus:
environments:
- development
replicated: true
development:
slave1:
adapter: postgresql
host: localhost
database: slaveapp_development
username: pguser
password: pgpass
The AR model Provider(I create the exact same tables in each app via Rake tasks) I'd like to sync/replicate to my slave:
class Provider < ActiveRecord::Base
has_many :products
replicated_model()
end
I boot both apps via Rails server and enter Masterapp's console and from there:
> Provider.using(:slave1).create({provider_params...})
#=> works! I get a new record in slave1's DB.
> Provider.using(:master).create({provider_params...})
#=> works partly. Creates record only in master's DB.
The problem is that when calling Provider.using(:master)... I'm expecting:
1 - Create record at master's DB.
2 - Replicate same record at slave1's DB. <--- This is NOT happening.
That is not the purpose of the Octopus gem.
It redirects the database requests, depending on whether it is a read or write operation. That way you can use your Rails models without thinking about the current database connection and if it fits the intended operation.
It does not copy the data to the slaves.
To perform the actual replication, i.e. the data transfer from the master to the slaves, you have to set it up yourself.
There are several options with PostgreSQL. If you are using a newer version (9.1+) you can use the integrated streaming replication in "hot standby" mode. There are tutorials on how to set it up, e.g.
If you are stuck with an older version of PostgreSQL have a look at the alternatives.