Mysql2::Error occured

[tackeyy]

I got below error when I run bundle exec rake db:migrate .

SSHKit::Command::Failed: rake exit status: 1
rake stdout: == 20170615082743 CreateOkuribitoRailsMethodCallSituations: migrating =========
-- create_table(:okuribito_rails_method_call_situations)
   -> 0.1109s
-- add_index(:okuribito_rails_method_call_situations, :class_name)
rake aborted!
StandardError: An error has occurred, all later migrations canceled:

Mysql2::Error: Index column size too large. The maximum column size is 767 bytes.: CREATE  INDEX `index_okuribito_rails_method_call_situations_on_class_name`  ON `okuribito_rails_method_call_situations` (`class_name`)

Enviroment

DB: AWS RDS
Gemfile:

'rails', '4.2.0'
'mysql2', '~> 0.3.17'

Ruby: 2.3.4

[tackeyy]

It depends on my mysql config.