Managing application settings for AB testing

Question

Pulumi · Accepted Answer

AB testing is a technique used to measure and compare the performance of different versions of an application or a web page by splitting the traffic among those versions and evaluating their impact on the user experience. When you want to manage application settings for AB testing, you typically need a way to dynamically adjust features and configuration settings without deploying new code.

For cloud applications, this often means using feature flags or similar toggles that can be controlled outside the application code, allowing teams to turn features on or off for specific segments of users. One tool that provides this capability is AWS AppConfig which is designed to enable developers to manage application configurations and feature flags safely, at scale, and without the need to deploy code or re-deploy the application.

Below is a Pulumi program in TypeScript that demonstrates how to create an AWS AppConfig configuration for managing application settings for AB testing. This program presupposes that you have an application that can be configured via AppConfig. The example focuses on creating an environment, a configuration profile, and a deployment strategy that could be used for AB testing:

```typescript
import * as pulumi from '@pulumi/pulumi';
import * as aws from '@pulumi/aws';

// Create an AppConfig application, which represents a logical unit of code such as a microservice.
const appConfigApplication = new aws.appconfig.Application('my-app-config', {
    // Application name.
    name: 'MyAppConfigApplication',
    // Application description.
    description: 'An AppConfig Application used for AB testing',
});

// Create an AppConfig environment, which represents a deployment target (such as a particular environment).
const appConfigEnvironment = new aws.appconfig.Environment('my-app-config-env', {
    // Reference to the AppConfig application ID.
    applicationId: appConfigApplication.applicationId,
    // Environment name.
    name: 'MyAppConfigEnvironment',
    // Environment description.
    description: 'An environment for AB testing',
});

// Create an AppConfig configuration profile, which is a schema that defines the configuration structure.
const appConfigProfile = new aws.appconfig.ConfigurationProfile('my-app-config-profile', {
    // Reference to the AppConfig application ID.
    applicationId: appConfigApplication.applicationId,
    // Configuration profile name.
    name: 'MyAppConfigProfile',
    // Format of the configuration (either `json` or `yaml`).
    locationUri: 'hosted', // Using AWS-hosted configuration
    // Configuration profile description.
    description: 'A configuration profile for AB testing',
});

// Create an AppConfig deployment strategy that defines how the configuration changes will be deployed.
const appConfigStrategy = new aws.appconfig.DeploymentStrategy('my-app-config-strategy', {
    // Deployment strategy name.
    name: 'MyAppConfigStrategy',
    // Deployment strategy description.
    description: 'A strategy for deploying AB testing configurations',
    // The minimum amount of time in minutes that AppConfig monitors for alarms before considering the deployment to be complete.
    deploymentDurationInMinutes: 0,
    // The amount of time AppConfig monitors for configuration changes.
    finalBakeTimeInMinutes: 0,
    // The percentage of targets to receive a deployed configuration during each interval of the deployment.
    growthFactor: 50,
    // The method used to distribute the deployment (can be either `linear` or `exponential`).
    growthType: 'linear',
    // The amount of time AppConfig waits for the configuration to propagate to the Amazon CloudWatch alarms.
    replicateTo: 'NONE', // Not replicating to multiple AWS Regions
});

// Example usage: Assume you have a JSON configuration for your application that you want to manage through AppConfig.
// You would put that configuration into an S3 bucket and then create an AppConfigHostedConfigurationVersion
// to point to it, and start a deployment to update your environment with that configuration.

export const applicationId = appConfigApplication.applicationId;
export const environmentId = appConfigEnvironment.environmentId;
export const configurationProfileId = appConfigProfile.configurationProfileId;
export const deploymentStrategyId = appConfigStrategy.deploymentStrategyId;
```

In this program:

- We use the `aws.appconfig.Application` resource to create our application's configuration container.
- We establish an environment with `aws.appconfig.Environment` which could represent a physical deployment stage like 'development', 'staging', or 'production'.
- The `aws.appconfig.ConfigurationProfile` defines the structure for a configuration, and in this case, we specify a hosted configuration which means AWS will host the content of our configuration.
- `aws.appconfig.DeploymentStrategy` allows us to set up rules for how changes to our configuration will be deployed. For AB testing, you might gradually increase the percentage of users who receive the new configuration.

This would set up the basic infrastructure for AB testing, and you'd dynamically adjust the configurations using AWS AppConfig during your tests. Remember, any changes to application settings require effective monitoring and data gathering to analyze the impact; ensure that your application is instrumented appropriately to collect this data.