Struct RetryPolicy 

pub struct RetryPolicy {
    pub max_attempts: u32,
    pub initial_delay: Duration,
    pub max_delay: Duration,
    pub backoff_factor: f64,
    pub jitter: f64,
    pub retry_on: RetryOn,
}

Available on crate feature graph only.

How many times a node is attempted, and how long between attempts.

Fields

max_attempts: u32

Total attempts, including the first. 1 means no retry.

initial_delay: Duration

Delay before the second attempt.

max_delay: Duration

Ceiling on any single delay.

backoff_factor: f64

Multiplier applied to the delay after each attempt.

jitter: f64

Fraction of the delay to vary randomly, so retries from many nodes do not align. 0.0 is exact, 1.0 varies the delay across its whole width.

retry_on: RetryOn

Which failures to retry.

Implementations

impl RetryPolicy

pub fn new(max_attempts: u32) -> RetryPolicy

A policy allowing max_attempts in total, with the other defaults.

pub fn with_initial_delay(self, delay: Duration) -> RetryPolicy

Set the delay before the second attempt.

pub fn with_max_delay(self, delay: Duration) -> RetryPolicy

Set the ceiling on any single delay.

pub fn with_backoff_factor(self, factor: f64) -> RetryPolicy

Set the multiplier applied after each attempt.

pub fn with_jitter(self, jitter: f64) -> RetryPolicy

Set how much the delay varies randomly, as a fraction of itself.

pub fn with_retry_on(self, retry_on: RetryOn) -> RetryPolicy

Set which failures to retry.

pub fn allows_another_attempt(&self, attempts_so_far: u32) -> bool

Whether another attempt is allowed after attempts_so_far failures.

pub fn delay_for_attempt(&self, attempt: u32) -> Duration

The delay before attempt number attempt, counting the first attempt as zero, so delay_for_attempt(1) precedes the second attempt.

The delay grows by backoff_factor each time, is clamped to max_delay, and is then varied by up to jitter of itself. A backoff_factor at or below zero is treated as 1.0, giving a constant delay rather than collapsing to nothing.

The clamp happens before the jitter, so a jittered delay can sit slightly above max_delay only when jitter is positive; with jitter at zero the ceiling is exact.

Trait Implementations

impl Clone for RetryPolicy

fn clone(&self) -> RetryPolicy

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for RetryPolicy

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl Default for RetryPolicy

Ten attempts, one second of initial delay, doubling to a sixty-second cap.

The nine sleeps between ten attempts total about 243 seconds, so a node that keeps failing takes roughly four minutes to give up, plus the time each attempt itself takes. Lower max_attempts where a caller is waiting.

Attaching no policy at all is still one attempt: this default applies only to a policy you construct.

fn default() -> RetryPolicy

Returns the “default value” for a type.