wow-api/me.ahoo.wow.api.annotation/Retry

Retry

@Target(allowedTargets = [AnnotationTarget.FUNCTION])

annotation class Retry(val enabled: Boolean = true, val maxRetries: Int = DEFAULT_MAX_RETRIES, val minBackoff: Int = DEFAULT_MIN_BACKOFF, val executionTimeout: Int = DEFAULT_EXECUTION_TIMEOUT, val recoverable: Array<KClass<out Throwable>> = [], val unrecoverable: Array<KClass<out Throwable>> = [])

Enables retry mechanism for annotated functions with configurable retry policies.

This annotation provides resilient error handling by automatically retrying failed operations according to specified policies. It's essential for handling transient failures in distributed systems, network operations, and external service calls.

The retry mechanism supports:

Exponential backoff with jitter
Configurable retry counts and timeouts
Selective exception handling (recoverable vs unrecoverable)
Circuit breaker patterns integration

Example usage:

class PaymentService {

    @Retry(
        maxRetries = 3,
        minBackoff = 1,
        recoverable = [IOException::class, TimeoutException::class],
        unrecoverable = [IllegalArgumentException::class]
    )
    fun processPayment(request: PaymentRequest): PaymentResult {
        // Network call that might fail temporarily
        return paymentGateway.charge(request)
    }

    @Retry(enabled = false)  // Disable retries for this operation
    fun validatePayment(request: PaymentRequest) {
        // Validation that should fail fast
        require(request.amount > 0) { "Amount must be positive" }
    }
}

Parameters

enabled

Whether retry functionality is enabled. Defaults to true.

maxRetries

Maximum number of retry attempts. Defaults to DEFAULT_MAX_RETRIES.

minBackoff

Minimum backoff duration in seconds before first retry. Uses exponential backoff for subsequent retries. See java.time.temporal.ChronoUnit.SECONDS for time units.

executionTimeout

Maximum timeout in seconds for each execution attempt. Prevents hanging operations. See java.time.temporal.ChronoUnit.SECONDS.

recoverable

Array of exception types that should trigger retries when encountered. Only these exceptions will cause retry attempts.

unrecoverable

Array of exception types that should NOT trigger retries. These exceptions fail immediately without retry.