Consultas de Rails/ActiveRecord con retrasos en la replicación

I have a master database (writes) and several slave databases (reads). There are times when querying a slave will not return a record that exists on the master database. This is caused by replication delays.

I'm hoping that queries expected to return a single record (querying a unique column like 'id') would behave as follows:

record = query_slave()
if record.nil?
  record = query_master()
end

Is there a gem which alleviates replication delay issues?