5.6 KiB
| id | title |
|---|---|
| toggle_variants | Feature Toggle Variants |
Every toggle in Unleash can have something called variants. Where feature toggles allow you to decide which users get access to a feature, toggle variants allow you to further split those users into segments. Say, for instance, that you're testing out a new feature, such as an alternate sign-up form. The feature toggle would expose the form only to a select group of users. The variants could decide whether the user sees a blue or a green submit button on that form.
Variants facilitate A/B testing and experimentation by letting you create controlled and measurable experiments. Check our blog post on using Unleash for A/B/n experiments for some more insights into how you can set it up.
What are variants?
Whenever you create a feature toggle, you can assign it any number of variants. This is commonly done in cases where you want to serve your users different versions of a feature to see which performs better.
A variant has four components that define it:
-
a name:
This must be unique among the toggle's variants. When working with a toggle with variants in a client, you will typically use variant name to find out which variant it is.
-
a weight:
The weight is the likelihood of any one user getting this specific variant. See the weights section for more info.
-
an optional payload:
A variant can also have an associated payload. Use this to deliver more data or context. See the payload section for a more details.
-
an optional override
Overrides let you specify that certain users (as identified either by their user ID or by another custom stickiness value) will always get this variant, regardless of the variant's weighting.
Variant weight
A variant's weight determines how likely it is that a user will receive that variant. It is a numeric value between 0 and 100 (inclusive) with one decimal's worth of precision.
When you have multiple variants, the sum of all their weights must add up to exactly 100. Depending on the weight type, Unleash may automatically determine the weight of the new variant and balance it out with the other variants.
Weight types
There are two kinds of variant weight types: variable and fixed. Unleash requires you to always have at least one variable weight variant.
The default weight type is variable. This means that the variant's weight will automatically adjust based on the number of other variable weight variants. All variable weight variants will receive an equal weighting (or as close as we can get with rounding) based on the available, non-fixed weight space. <— whew, rewrite this.
When creating a variant, you can also give it a fixed weight.
Variant payload
Overrides
Stickiness
Do you want to facilitate more advanced experimentations? Do you want to use Unleash to handle your A/B experiments? Say hello to feature toggle variants!
You can now extend feature toggles with multiple variants. This feature enables you to extend a feature toggle to divide your traffic among a set of variants.
How do I configure variants
How does it work?
Unleash will first use activation strategies to decide whether a feature toggle is considered enabled or disabled for the current user.
If the toggle is considered enabled, the Unleash client will select the correct variant for the request. Unleash clients will use values from the Unleash context to make the allocation predictable. UserId is the preferred value, then sessionId and remoteAdr. If no context data is provided, the traffic will be spread randomly for each request.
If the toggle is considered disabled you will get the built-in disabled variant.
A json representation of the empty variant will be the following:
{
"name": "disabled",
"enabled": false
}
The actual representation of the built-in the client SDK will vary slightly, to honor best practices in various languages.
If you change the number of variants, it will affect variant allocations. This means that some of the users will be moved to the next variant.
Java SDK example:
Variant variant = unleash.getVariant("toggle.name", unleashContext);
System.out.println(variant.getName());
Variant payload types
Client SDK Support
To make use of toggle variants, you need to use a compatible client. Client SDK with variant support:
- unleash-client-node (from v3.2.0)
- unleash-client-java (from v3.2.0)
- unleash-client-ruby (from v0.1.6)
- unleash-client-python (from v3.3.0)
- unleash-client-dotnet (from v1.3.6)
- unleash-client-go (from v3 branch)
- unleash-client-php (from v1.0.0)
If you would like to give feedback on this feature, experience issues or have questions, please feel free to open an issue on GitHub.