Storage Service

The SDK operates in a stateless mode by default, meaning each get_flag call triggers a fresh evaluation of the flag against the current user context.

To optimize performance and maintain consistency, you can implement a custom storage mechanism by passing a storage parameter during initialization. This allows you to persist feature flag decisions in your preferred database system (like Redis, MongoDB, or any other data store).

Key benefits of implementing storage:

1. Improved performance by caching decisions
2. Consistent user experience across sessions
3. Reduced load on your application

The storage mechanism ensures that once a decision is made for a user, it remains consistent even if campaign settings are modified in the VWO Application. This is particularly useful for maintaining a stable user experience during A/B tests and feature rollouts.

How to Implement a Storage Service

Storage Service is optional while instantiating the VWO SDK. However, to ensure sticky variation assignments, we recommend implementing it.

Usage

using System;
using System.Collections.Generic;
using VWOFmeSdk.Packages.Storage;

public class StorageConnector : Connector
{
   public override object Get(string featureKey, string userId)
   {
       // Retrieve data based on featureKey and userId
       return null;
   }

   public override void Set(Dictionary<string, object> data)
   {
       // Store data based on data["featureKey"] and data["userId"]
   }
}

var vwoInitOptions = new VWOInitOptions
{
   SdkKey = "32-alpha-numeric-sdk-key",
   AccountId = 123456,
   Storage = new StorageConnector()
};

Storage Service should expose two methods: get and set. These methods are used by VWO whenever there is a need to read or write from the storage service.