Override master db selection method not working

[aman199002]

I need to modify the default condition for master db selection in my application based on some cached value. I have defined a custom proxy class as mentioned in documentation in config/initializers directory.

class MyAwesomeSqlProxy < ::Makara::Proxy
  hijack_method :select, :ping
  send_to_all :connect, :reconnect, :disconnect, :clear_cache

  def connection_for(config)
    ::Sql::Client.new(config)
  end

  def needs_master?(method_name, args)
    # Modified this method for testing to always route to master    
    return true  
  end
end

Any changes in this class does not seem to work. Do I need to define this class at some other location and load explicitly? Or this feature to override db selection is not supported as mentioned in documentation?

[bleonard]

It's been awhile for sure, but I don't see your database.yml here. There is some thing to set this Proxy to the adapter: in your database.yml.

I'd consider extending to one you need, too. For example if you are using MySQL, do

module ActiveRecord
  module ConnectionAdapters
    class MakaraTestingAdapter < ActiveRecord::ConnectionAdapters::MakaraMysql2Adapter
       def needs_primary?(method_name, args)
          # Modified this method for testing to always route to primary    
          return true  
      end
  end
end

database.yml

production:
  adapter: 'testing'

  makara:
   ...

[aman199002]

I tried the same with postgresql as mentioned below.

config/initializes/postgresql_makara_custom_adapter.rb

module ActiveRecord
  module ConnectionAdapters
    class PostgresqlMakaraCustomAdapter < ::Makara::Proxy
      
      def needs_primary?(method_name, args)
          # Modified this method for testing to always route to primary    
          return true  
      end

    end
  end
end
  

database.yml

production:
  adapter: 'postgresql_makara_custom'
  makara:
   ...

Getting active_record error on load when running the application: activerecord-5.1.4/lib/active_record/connection_adapters/connection_specification.rb:196:in `spec': undefined method `config' for #<Hash:0x00007fc4a0e036e0> (NoMethodError)

However I checked the code inside gem and tried by overriding the makara_abstract_adapter class via monkey patching in my application as mentioned below: config/initializes/makara_abstract_adapter.rb

module ActiveRecord
  module ConnectionAdapters
    class MakaraAbstractAdapter < ::Makara::Proxy

      protected

      def needs_master?(method_name, args)
        return true if replication_lag?
        sql = coerce_query_to_sql_string(args.first)
        return true if sql_master_matchers.any?{|m| sql =~ m }
        return false if sql_slave_matchers.any?{|m| sql =~ m }
        true
      end
      
      private

      def replication_lag?
        ....
      end

    end
  end
end

database.yml

production:
  adapter: postgresql_makara
  makara:
   ...

The same is working and I can modify the condition inside needs_master method.