Enum JitterPolicy 

#[non_exhaustive]
pub enum JitterPolicy {
    None,
    Full,
    Equal,
    RandomizedBand,
}

Policy controlling randomization of retry delays.

Most users configure this through BackoffPolicy.

Trade-offs

• RandomizedBand: can exceed the base delay when used by BackoffPolicy.
• Equal: balanced; keeps about 75% of the base delay on average.
• None: predictable, but retries can line up.
• Full: widest spread below the base delay.

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

None

No jitter: use exact backoff delay.

Use when:

• Only one task retrying (no herd risk)
• Predictable timing required
• Testing/debugging

Full

Full jitter: random delay in [0, backoff_delay].

Most aggressive jitter, can significantly reduce delay. Use when maximum load spreading is needed.

Equal

Equal jitter: delay/2 + random[0, delay/2].

Balances predictability with randomness (recommended default). Preserves ~75% of the original backoff on average.

RandomizedBand

Randomized wideband.

When used by BackoffPolicy::next, the delay is drawn from:

[first, min(base * 3, max)]

Here base is the current retry delay before jitter: first * factor^attempt, capped at max.

Implementations

impl JitterPolicy

pub fn apply(&self, delay: Duration) -> Duration

Applies context-free jitter to delay.

RandomizedBand needs first and max to build its full band. This method does not have that context, so RandomizedBand falls back to Full-style jitter: [0, delay].

For full band behavior, use Self::apply_randomized_band.

pub fn apply_randomized_band( &self, lower: Duration, upper_seed: Duration, max: Duration, ) -> Duration

Draws a uniform random delay over the band [lower, min(upper_seed × 3, max)].

Trait Implementations

impl Clone for JitterPolicy

fn clone(&self) -> JitterPolicy

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for JitterPolicy

impl Debug for JitterPolicy

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

Formats the value using the given formatter.

impl Default for JitterPolicy

fn default() -> Self

Returns JitterPolicy::None as default (backwards compatible).

impl Eq for JitterPolicy

impl PartialEq for JitterPolicy

fn eq(&self, other: &JitterPolicy) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for JitterPolicy