google-adk-kotlin-core/com.google.adk.kt.retry/ExponentialBackoff

ExponentialBackoff

data class ExponentialBackoff(val maxAttempts: Int = DEFAULT_MAX_ATTEMPTS, val initialDelay: Duration = DEFAULT_INITIAL_DELAY, val maxDelay: Duration = DEFAULT_MAX_DELAY, val backoffFactor: Double = DEFAULT_BACKOFF_FACTOR, val jitter: Double = DEFAULT_JITTER) : RetryPolicy

A RetryPolicy that retries every failure with exponentially growing, capped and jittered delays.

Constructors

ExponentialBackoff

constructor(maxAttempts: Int = DEFAULT_MAX_ATTEMPTS, initialDelay: Duration = DEFAULT_INITIAL_DELAY, maxDelay: Duration = DEFAULT_MAX_DELAY, backoffFactor: Double = DEFAULT_BACKOFF_FACTOR, jitter: Double = DEFAULT_JITTER)

Types

Builder

class Builder

Fluent builder for ExponentialBackoff, provided primarily for Java callers. Any property left unset falls back to the same default as the constructor.

Companion

object Companion

Properties

backoffFactor

val backoffFactor: Double

Multiplier applied to the delay after each retry. Defaults to 2.0.

initialDelay

val initialDelay: Duration

Delay before the first retry. Defaults to 1 second.

jitter

val jitter: Double

Randomness factor, not a duration: each delay is multiplied by a random factor in [1 - jitter, 1 + jitter], never going below zero, after being capped low enough that the result stays within maxDelay; 0 removes randomness. Defaults to 1.0.

maxAttempts

val maxAttempts: Int

Attempts including the first, so 1 disables retries. Defaults to 5.

maxDelay

val maxDelay: Duration

Upper bound on any single delay. Defaults to 60 seconds.

Functions

initialDelayMillis

fun initialDelayMillis(): Long

Returns initialDelay in whole milliseconds. Java cannot read initialDelay (mangled).

maxDelayMillis

fun maxDelayMillis(): Long

Returns maxDelay in whole milliseconds. Java cannot read maxDelay (mangled).

nextRetryDelay

open override fun nextRetryDelay(failedAttempts: Int): Duration

Returns the delay before the next attempt once failedAttempts attempts have failed, and is called only after shouldRetry returned true. A zero or negative delay retries at once, and Duration.INFINITE waits until the retrying coroutine is canceled.

shouldRetry

open override fun shouldRetry(failure: Exception, failedAttempts: Int): Boolean

Returns whether to retry once failedAttempts attempts (at least 1) have failed, the last with failure.

toBuilder

fun toBuilder(): ExponentialBackoff.Builder

Returns a Builder initialized with this instance's properties, primarily for Java callers. Prefer it over copy from Java: copy takes every property positionally, so its signature changes whenever a property is added.