pub struct PeakEwma<S, C = CompleteOnResponse> { /* private fields */ }Expand description
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
This is derived from Finagle, which is distributed under the Apache V2 license. Copyright 2017, Twitter Inc.
Implementations
Trait Implementations
sourceimpl<S, C, Request> Service<Request> for PeakEwma<S, C> where
S: Service<Request>,
C: TrackCompletion<Handle, S::Response>,
impl<S, C, Request> Service<Request> for PeakEwma<S, C> where
S: Service<Request>,
C: TrackCompletion<Handle, S::Response>,
type Response = <C as TrackCompletion<Handle, <S as Service<Request>>::Response>>::Output
type Response = <C as TrackCompletion<Handle, <S as Service<Request>>::Response>>::Output
Responses given by the service.
type Future = TrackCompletionFuture<<S as Service<Request>>::Future, C, Handle>
type Future = TrackCompletionFuture<<S as Service<Request>>::Future, C, Handle>
The future response value.
Auto Trait Implementations
impl<S, C> RefUnwindSafe for PeakEwma<S, C> where
C: RefUnwindSafe,
S: RefUnwindSafe,
impl<S, C> Send for PeakEwma<S, C> where
C: Send,
S: Send,
impl<S, C> Sync for PeakEwma<S, C> where
C: Sync,
S: Sync,
impl<S, C> Unpin for PeakEwma<S, C> where
C: Unpin,
S: Unpin,
impl<S, C> UnwindSafe for PeakEwma<S, C> where
C: UnwindSafe,
S: UnwindSafe,
Blanket Implementations
sourceimpl<T> BorrowMut<T> for T where
T: ?Sized,
impl<T> BorrowMut<T> for T where
T: ?Sized,
const: unstable · sourcefn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more
sourceimpl<T> Instrument for T
impl<T> Instrument for T
sourcefn instrument(self, span: Span) -> Instrumented<Self>
fn instrument(self, span: Span) -> Instrumented<Self>
Instruments this type with the provided Span, returning an
Instrumented wrapper. Read more
sourcefn in_current_span(self) -> Instrumented<Self>
fn in_current_span(self) -> Instrumented<Self>
sourceimpl<T, Request> ServiceExt<Request> for T where
T: Service<Request> + ?Sized,
impl<T, Request> ServiceExt<Request> for T where
T: Service<Request> + ?Sized,
sourcefn ready(&mut self) -> Ready<'_, Self, Request>ⓘNotable traits for Ready<'a, T, Request>impl<'a, T, Request> Future for Ready<'a, T, Request> where
T: Service<Request>, type Output = Result<&'a mut T, T::Error>; where
Self: Sized,
fn ready(&mut self) -> Ready<'_, Self, Request>ⓘNotable traits for Ready<'a, T, Request>impl<'a, T, Request> Future for Ready<'a, T, Request> where
T: Service<Request>, type Output = Result<&'a mut T, T::Error>; where
Self: Sized,
T: Service<Request>, type Output = Result<&'a mut T, T::Error>;
Yields a mutable reference to the service when it is ready to accept a request.
sourcefn ready_and(&mut self) -> ReadyAnd<'_, Self, Request> where
Self: Sized,
fn ready_and(&mut self) -> ReadyAnd<'_, Self, Request> where
Self: Sized,
please use the ServiceExt::ready method instead
Yields a mutable reference to the service when it is ready to accept a request.
sourcefn ready_oneshot(self) -> ReadyOneshot<Self, Request>ⓘNotable traits for ReadyOneshot<T, Request>impl<T, Request> Future for ReadyOneshot<T, Request> where
T: Service<Request>, type Output = Result<T, T::Error>; where
Self: Sized,
fn ready_oneshot(self) -> ReadyOneshot<Self, Request>ⓘNotable traits for ReadyOneshot<T, Request>impl<T, Request> Future for ReadyOneshot<T, Request> where
T: Service<Request>, type Output = Result<T, T::Error>; where
Self: Sized,
T: Service<Request>, type Output = Result<T, T::Error>;
Yields the service when it is ready to accept a request.
sourcefn oneshot(self, req: Request) -> Oneshot<Self, Request>ⓘNotable traits for Oneshot<S, Req>impl<S, Req> Future for Oneshot<S, Req> where
S: Service<Req>, type Output = Result<S::Response, S::Error>; where
Self: Sized,
fn oneshot(self, req: Request) -> Oneshot<Self, Request>ⓘNotable traits for Oneshot<S, Req>impl<S, Req> Future for Oneshot<S, Req> where
S: Service<Req>, type Output = Result<S::Response, S::Error>; where
Self: Sized,
S: Service<Req>, type Output = Result<S::Response, S::Error>;
Consume this Service, calling with the providing request once it is ready.
sourcefn call_all<S>(self, reqs: S) -> CallAll<Self, S> where
Self: Sized,
Self::Error: Into<BoxError>,
S: Stream<Item = Request>,
fn call_all<S>(self, reqs: S) -> CallAll<Self, S> where
Self: Sized,
Self::Error: Into<BoxError>,
S: Stream<Item = Request>,
sourcefn and_then<F>(self, f: F) -> AndThen<Self, F> where
Self: Sized,
F: Clone,
fn and_then<F>(self, f: F) -> AndThen<Self, F> where
Self: Sized,
F: Clone,
Executes a new future after this service’s future resolves. This does
not alter the behaviour of the poll_ready method. Read more
sourcefn map_response<F, Response>(self, f: F) -> MapResponse<Self, F> where
Self: Sized,
F: FnOnce(Self::Response) -> Response + Clone,
fn map_response<F, Response>(self, f: F) -> MapResponse<Self, F> where
Self: Sized,
F: FnOnce(Self::Response) -> Response + Clone,
Maps this service’s response value to a different value. This does not
alter the behaviour of the poll_ready method. Read more
sourcefn map_err<F, Error>(self, f: F) -> MapErr<Self, F> where
Self: Sized,
F: FnOnce(Self::Error) -> Error + Clone,
fn map_err<F, Error>(self, f: F) -> MapErr<Self, F> where
Self: Sized,
F: FnOnce(Self::Error) -> Error + Clone,
Maps this service’s error value to a different value. This does not
alter the behaviour of the poll_ready method. Read more
sourcefn map_result<F, Response, Error>(self, f: F) -> MapResult<Self, F> where
Self: Sized,
Error: From<Self::Error>,
F: FnOnce(Result<Self::Response, Self::Error>) -> Result<Response, Error> + Clone,
fn map_result<F, Response, Error>(self, f: F) -> MapResult<Self, F> where
Self: Sized,
Error: From<Self::Error>,
F: FnOnce(Result<Self::Response, Self::Error>) -> Result<Response, Error> + Clone,
Maps this service’s result type (Result<Self::Response, Self::Error>)
to a different value, regardless of whether the future succeeds or
fails. Read more
sourcefn map_request<F, NewRequest>(self, f: F) -> MapRequest<Self, F> where
Self: Sized,
F: FnMut(NewRequest) -> Request,
fn map_request<F, NewRequest>(self, f: F) -> MapRequest<Self, F> where
Self: Sized,
F: FnMut(NewRequest) -> Request,
Composes a function in front of the service. Read more
sourcefn then<F, Response, Error, Fut>(self, f: F) -> Then<Self, F> where
Self: Sized,
Error: From<Self::Error>,
F: FnOnce(Result<Self::Response, Self::Error>) -> Fut + Clone,
Fut: Future<Output = Result<Response, Error>>,
fn then<F, Response, Error, Fut>(self, f: F) -> Then<Self, F> where
Self: Sized,
Error: From<Self::Error>,
F: FnOnce(Result<Self::Response, Self::Error>) -> Fut + Clone,
Fut: Future<Output = Result<Response, Error>>,
Composes an asynchronous function after this service. Read more
sourcefn map_future<F, Fut, Response, Error>(self, f: F) -> MapFuture<Self, F> where
Self: Sized,
F: FnMut(Self::Future) -> Fut,
Error: From<Self::Error>,
Fut: Future<Output = Result<Response, Error>>,
fn map_future<F, Fut, Response, Error>(self, f: F) -> MapFuture<Self, F> where
Self: Sized,
F: FnMut(Self::Future) -> Fut,
Error: From<Self::Error>,
Fut: Future<Output = Result<Response, Error>>,
Composes a function that transforms futures produced by the service. Read more