pub struct PeakEwma<S, C = CompleteOnResponse> { /* private fields */ }
Available on crate feature load only.
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

Wraps an S-typed service so that its load is tracked by the EWMA of its peak latency.

Trait Implementations

Formats the value using the given formatter. Read more

A comparable load metric. Read more

Estimate the service’s current load.

Responses given by the service.

Errors produced by the service.

The future response value.

Returns Poll::Ready(Ok(())) when the service is able to process requests. Read more

Process the request and return the response asynchronously. Read more

Auto Trait Implementations

Blanket Implementations

Gets the TypeId of self. Read more

Immutably borrows from an owned value. Read more

Mutably borrows from an owned value. Read more

Returns the argument unchanged.

Instruments this type with the provided Span, returning an Instrumented wrapper. Read more

Instruments this type with the current Span, returning an Instrumented wrapper. Read more

Calls U::from(self).

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

Available on crate feature util only.

Yields a mutable reference to the service when it is ready to accept a request.

👎 Deprecated since 0.4.6:

please use the ServiceExt::ready method instead

Available on crate feature util only.

Yields a mutable reference to the service when it is ready to accept a request.

Available on crate feature util only.

Yields the service when it is ready to accept a request.

Available on crate feature util only.

Consume this Service, calling with the providing request once it is ready.

Available on crate feature util only.

Process all requests from the given Stream, and produce a Stream of their responses. Read more

Available on crate feature util only.

Executes a new future after this service’s future resolves. This does not alter the behaviour of the poll_ready method. Read more

Available on crate feature util only.

Maps this service’s response value to a different value. This does not alter the behaviour of the poll_ready method. Read more

Available on crate feature util only.

Maps this service’s error value to a different value. This does not alter the behaviour of the poll_ready method. Read more

Available on crate feature util only.

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

Available on crate feature util only.

Composes a function in front of the service. Read more

Available on crate features util and filter only.

Composes this service with a Filter that conditionally accepts or rejects requests based on a predicate. Read more

Available on crate features util and filter only.

Composes this service with an AsyncFilter that conditionally accepts or rejects requests based on an [async predicate]. Read more

Available on crate feature util only.

Composes an asynchronous function after this service. Read more

Available on crate feature util only.

Composes a function that transforms futures produced by the service. Read more

Available on crate feature util only.

Convert the service into a Service + Send trait object. Read more

Available on crate feature util only.

Convert the service into a Service + Clone + Send trait object. Read more

The type returned in the event of a conversion error.

Performs the conversion.

The type returned in the event of a conversion error.

Performs the conversion.

Attaches the provided Subscriber to this type, returning a WithDispatch wrapper. Read more

Attaches the current default Subscriber to this type, returning a WithDispatch wrapper. Read more