Variation Distribution

When running an A/B Test, you need to assign users to Variations and implement logic for each Variation. You can use the Hackle SDK to handle this user distribution.

variation

When using the Java/Kotlin SDK, duplicate exposure events for the same A/B Test distribution result triggered consecutively by the same user within 1 minute are removed.

Events within 1 minute are counted as 1 occurrence.

Cohort Targeting is not supported in the Server SDK. If the Targeting includes a cohort, please run the test using the Client SDK.

Pass the Experiment Key and User Identifier to the variation() method to assign users to a Variation and receive the result. Then implement logic for each Variation.

In the example code below, Experiment Key 42 is passed and the User Identifier is "ae2182e0". There are two Variations: A and B.

Kotlin

import io.hackle.sdk.HackleClient
import io.hackle.sdk.common.Variation

// Determines which Variation to show to the user identified as "ae2182e0"
// in the A/B Test with Experiment Key 42.
// Returns Variation A if a decision cannot be made.
val variation: Variation = hackleClient.variation(42, "ae2182e0")

// Logic for the assigned Variation
if (variation == Variation.A) {
  // Group A logic
} else if (variation == Variation.B) {
  // Group B logic
}

Java

variationDetail

The variationDetail() method works the same as variation() but additionally provides the reason for being assigned to a specific group. This method is useful for verifying that distribution is working correctly. You must pass the Experiment Key as a parameter. In the example code below, Experiment Key 42 is passed.

Kotlin

import io.hackle.sdk.HackleClient
import io.hackle.sdk.common.Variation
import io.hackle.sdk.common.decision.Decision
import io.hackle.sdk.common.decision.DecisionReason

// Variation distribution decision detail
val decision: Decision = hackleClient.variationDetail(42, "ae2182e0")

// Assigned Variation
val variation: Variation = decision.variation

// Decision reason
val reason: DecisionReason = decision.reason

Java

The decision reason is returned in a format such as SDK_NOT_READY. Refer to the table below for details.

Distribution Reason	Description	Distribution Result
SDK_NOT_READY	The SDK is not ready to use. (e.g., initialization attempted with an invalid SDK Key)	A (Control Group)
EXPERIMENT_NOT_FOUND	No A/B Test was found for the provided Experiment Key. The Experiment Key may be incorrect, or the experiment may be archived.	A (Control Group)
NOT_IN_MUTUAL_EXCLUSION_EXPERIMENT	The experiment is included in Mutually Exclusive Settings, but the user was not assigned to that Mutually Exclusive Group.	A (Control Group)
EXPERIMENT_DRAFT	The A/B Test is in draft state.	A (Control Group)
EXPERIMENT_PAUSED	The A/B Test is paused.	A (Control Group)
EXPERIMENT_COMPLETED	The A/B Test has ended.	Winning Variation selected at completion
OVERRIDDEN	The user was assigned to a specific group by Override.	Override-assigned group
NOT_IN_EXPERIMENT_TARGET	The user is not an A/B Test target.	A (Control Group)
TRAFFIC_NOT_ALLOCATED	The A/B Test is running, but the user was not allocated to the test.	A (Control Group)
TRAFFIC_ALLOCATED	The user has been allocated to the A/B Test.	Allocated group
VARIATION_DROPPED	The originally allocated group has been removed from the test.	A (Control Group)
INVALID_INPUT	The input value is invalid.	A (Control Group)
EXCEPTION	An unknown error occurred.	A (Control Group)

Parameters

• You can also receive the parameter values for the assigned Variation through the variationDetail() method.

• The Decision instance returned by variationDetail() contains a ParameterConfig object with the full parameter configuration.

• Since parameter values configured in the Hackle A/B Test screen are stored as key-value pairs, use the methods below according to the parameter type to retrieve the configured values.

Kotlin

getString

• Returns parameter values configured as STRING or JSON type.

• Returns the value configured for the assigned Variation.

import io.hackle.sdk.HackleClient
import io.hackle.sdk.common.decision.Decision
import io.hackle.sdk.common.decision.DecisionReason

val decision: Decision = hackleClient.variationDetail(42, "ae2182e0")
val config: ParameterConfig = decision.config

val strValue: String = decision.getString("parameter_key_string_type", "defaultValue")
val strValueInConfig: String = config.getString("parameter_key_string_type", "defaultValue")

val jsonValue: String = decision.getString("parameter_key_json_type", "defaultValue")
val jsonValueInConfig: String = config.getString("parameter_key_json_type", "defaultValue")

getInt

• Returns parameter values configured as Number type as an Int.

• Returns the value configured for the assigned Variation.

import io.hackle.sdk.HackleClient
import io.hackle.sdk.common.decision.Decision

val decision: Decision = hackleClient.variationDetail(42, "ae2182e0")
val config: ParameterConfig = decision.config

val intValue: Int = decision.getInt("parameter_key_number_type", 0)
val intValueInConfig: Int = config.getInt("parameter_key_number_type", 0)

getDouble

• Returns parameter values configured as Number type as a Double.

• Returns the value configured for the assigned Variation.

import io.hackle.sdk.HackleClient
import io.hackle.sdk.common.decision.Decision

val decision: Decision = hackleClient.variationDetail(42, "ae2182e0")
val config: ParameterConfig = decision.config

val doubleValue: Double = decision.getDouble("parameter_key_number_type", 0.0)
val doubleValueInConfig: Double = config.getDouble("parameter_key_number_type", 0.0)

getLong

• Returns parameter values configured as Number type as a Long.

• Returns the value configured for the assigned Variation.

import io.hackle.sdk.HackleClient
import io.hackle.sdk.common.decision.Decision

val decision: Decision = hackleClient.variationDetail(42, "ae2182e0")
val config: ParameterConfig = decision.config

val longValue: Long = decision.getLong("parameter_key_number_type", 0L)
val longValueInConfig: Long = config.getLong("parameter_key_number_type", 0L)

getBoolean

• Returns parameter values configured as Boolean type.

• Returns the value configured for the assigned Variation.

import io.hackle.sdk.HackleClient
import io.hackle.sdk.common.decision.Decision

val decision: Decision = hackleClient.variationDetail(42, "ae2182e0")
val config: ParameterConfig = decision.config

val booleanValue: Boolean = decision.getBoolean("parameter_key_boolean_type", false)
val booleanValueInConfig: Boolean = config.getBoolean("parameter_key_boolean_type", false)

Java