Struct `PeakEwma`

struct PeakEwma<S, C = super::completion::CompleteOnResponse> { ... }

Measures the load of the underlying service using Peak-EWMA load measurement.

PeakEwma implements Load with the Cost metric that estimates the amount of pending work to an endpoint. Work is calculated by multiplying the exponentially-weighted moving average (EWMA) of response latencies by the number of pending requests. The Peak-EWMA algorithm is designed to be especially sensitive to worst-case latencies. Over time, the peak latency value decays towards the moving average of latencies to the endpoint.

When no latency information has been measured for an endpoint, an arbitrary default RTT of 1 second is used to prevent the endpoint from being overloaded before a meaningful baseline can be established..

Note

Implementations

`impl<S, C> PeakEwma<S, C>`

fn new(service: S, default_rtt: Duration, decay_ns: f64, completion: C) -> Self: Wraps an S-typed service so that its load is tracked by the EWMA of its peak latency.

`impl<M, S, Target, Request> MakeService for PeakEwma<S, C>`

fn poll_ready(self: &mut Self, cx: &mut Context<'_>) -> Poll<Result<(), <M as MakeService<Target, Request>>::MakeError>>
fn make_service(self: &mut Self, target: Target) -> <M as MakeService<Target, Request>>::Future

`impl<S, C> Freeze for PeakEwma<S, C>`

`impl<S, C> Load for PeakEwma<S, C>`

fn load(self: &Self) -> <Self as >::Metric

`impl<S, C> RefUnwindSafe for PeakEwma<S, C>`

`impl<S, C> Send for PeakEwma<S, C>`

`impl<S, C> Sync for PeakEwma<S, C>`

`impl<S, C> Unpin for PeakEwma<S, C>`

`impl<S, C> UnwindSafe for PeakEwma<S, C>`

`impl<S, C, Request> Service for PeakEwma<S, C>`

fn poll_ready(self: &mut Self, cx: &mut Context<'_>) -> Poll<Result<(), <Self as >::Error>>
fn call(self: &mut Self, req: Request) -> <Self as >::Future

`impl<S: $crate::fmt::Debug, C: $crate::fmt::Debug> Debug for PeakEwma<S, C>`

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

`impl<T> Any for PeakEwma<S, C>`

fn type_id(self: &Self) -> TypeId

`impl<T> Borrow for PeakEwma<S, C>`

fn borrow(self: &Self) -> &T

`impl<T> BorrowMut for PeakEwma<S, C>`

fn borrow_mut(self: &mut Self) -> &mut T

`impl<T> From for PeakEwma<S, C>`

fn from(t: T) -> T: Returns the argument unchanged.

`impl<T> Instrument for PeakEwma<S, C>`

`impl<T> WithSubscriber for PeakEwma<S, C>`

`impl<T, Request> ServiceExt for PeakEwma<S, C>`

`impl<T, U> Into for PeakEwma<S, C>`

fn into(self: Self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of [From]<T> for U chooses to do.

`impl<T, U> TryFrom for PeakEwma<S, C>`

fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

`impl<T, U> TryInto for PeakEwma<S, C>`

fn try_into(self: Self) -> Result<U, <U as TryFrom<T>>::Error>