Update methods sent to read-only database with identity_cache gem

[gaga5lala]

Hi, I've encountered a shard mismatch problem when using octopus with identity_cache gem.

Environment

Databases:

• master * 1
• replica * 1

Config:

• replicated: true
• fully_replicated: false (set replicated_model by ourself)

Gems:

• rails 4.2.11
• octopus: 0.10.2
• identity_cache: 0.4.1

Scenario

Model

• User (replicated_model)
  • has_one :setting
• Setting (replicated_model)

When I want to update the setting record fetched from cache, the update query will be sent to the replica shard.

# in controller

# first request works, later requests all failed
User.fetch(1).setting.update(some_attribute)

By using binding.pry I found that first time .current_shard will return :master, record fetched by another request will get :replica then the update query sent to wrong replica database.

But if I using normal Active Record method (e.g. Member.find(1).setting.update(some_attribute)) all request are success.

Is there some class variables stored across requests but computing after ActiveRecord instance initialize, but record initialized by IdentityCache cause the problem?

Thanks