Struct futures_backoff::Strategy

pub struct Strategy { /* fields omitted */ }

Configurable retry strategy.

Implements Default, which returns an exponential backoff strategy with a delay of 1 second and a maximum of 5 retries.

Example

let strategy = Strategy::default()
    .with_max_retries(3);

let future = strategy.retry(|| {
    // do some real-world stuff here...
    future::ok::<u32, ::std::io::Error>(42)
});

Methods

impl Strategy

pub fn exponential(delay: Duration) -> Strategy

Creates a retry strategy driven by exponential back-off.

The specified duration will be multiplied by 2^n, where n is the number of failed attempts.

pub fn fibonacci(delay: Duration) -> Strategy

Creates a retry strategy driven by a fibonacci back-off.

The specified duration will be multiplied by fib(n), where n is the number of failed attempts.

Depending on the problem at hand, a fibonacci retry strategy might perform better and lead to better throughput than the ExponentialBackoff strategy.

See "A Performance Comparison of Different Backoff Algorithms under Different Rebroadcast Probabilities for MANETs." for more details.

pub fn fixed(delay: Duration) -> Strategy

Creates a retry strategy driven by a fixed delay.

pub fn with_max_delay(self, duration: Duration) -> Self

Sets the maximum delay between two attempts.

By default there is no maximum.

pub fn with_max_retries(self, retries: usize) -> Self

Sets the maximum number of retry attempts.

By default a retry will be attempted 5 times before giving up.

pub fn with_jitter(self, jitter: bool) -> Self

Enables or disables jitter on the delay.

Jitter will introduce a random variance to the retry strategy, which can be helpful to mitigate the "Thundering Herd" problem.

pub fn retry<A: Action>(&self, action: A) -> Retry<A>

Run the given action, and use this strategy to retry on failure.

pub fn retry_if<A: Action, C>(&self, action: A, condition: C) -> RetryIf<A, C> where
    C: Condition<A::Error>, 

Run the given action, and use this strategy to retry on failure if the error satisfies a given condition.

Trait Implementations

impl Debug for Strategy

fn fmt(&self, __arg_0: &mut Formatter) -> Result

Formats the value using the given formatter.

impl Default for Strategy

fn default() -> Strategy

Returns the "default value" for a type.