Persistent Assignment
Persistent assignment allows you to ensure that a user's variant stays consistent while an experiment is running, regardless of changes to allocation or targeting.
Persistent Storage Adapter
The persistent storage adapter allows you to plug in your own storage solution that Statsig SDK uses to persist user assignments.
The storage interface consists of just a load
and save
API for read/write operations.
info
Currently only supported in Go
, Ruby
, Node
Persistent Storage Logic
- Providing a storage adapter on Statsig initialization will give the SDK access to read & write on your custom storage
- Providing user persisted values to
get_experiment
will inform the SDK to- save the evaluation of the current user on first evaluation
- load the previously saved evaluation of a persisted user on subsequent evaluations
Example usage
Statsig.initialize(
'secret-key',
StatsigOptions.new(
user_persistent_storage: DummyPersistentStorageAdapter.new
)
)
persisted_user = StatsigUser.new({ 'userID' => 'test-123' })
exp = Statsig.get_experiment( # User gets saved to persisted storage
persisted_user,
'active_experiment',
Statsig::GetExperimentOptions.new(
user_persisted_values: Statsig.get_user_persisted_values(persisted_user, 'userID')
)
)
puts exp.group_name # 'Control'
exp = Statsig.get_experiment( # User evaluates using values from persisted storage
StatsigUser.new({'userID' => 'unknown'}),
'active_experiment',
Statsig::GetExperimentOptions.new(
user_persisted_values: Statsig.get_user_persisted_values(persisted_user, 'userID')
)
)
puts exp.group_name # 'Control'