Gem for Master-slave Replication

Hi, I'm trying to make master-slave replication(One master(write/read) and one slave(read only)) for my database(mysql 8 / rails 4.2). I researched whole day but I'm still considering which gem is best for performance and reliability(makara or octopus). Those databases will using in three rails apps. Please give me the advise which gem will be more reliable or let me know if there is the better way to implement master-slave replication.